The unique aspects of many sports result in patterns of injury that are different than those of the general athletic population. It is often instructive for sports and exercise medicine physicians to have a basic understanding of the patient’s sport to adequately formulate a differential diagnosis, plan treatment, guide rehabilitation, and decide on criteria for return to play. This chapter provides a summary of how various sports are played and discusses the epidemiology and mechanisms of injury within each sport.
Baseball is thought to be the second most commonly played team sport in the United States, with approximately 19 million people involved in playing every year. It is a ball-and-bat sport played by two teams with nine players on each side. The goal is to score “runs” by hitting a thrown ball and advancing around four bases. The game is broken up into nine sections, termed “innings,” during which each team has an opportunity to play offense (“at bat”) and defense (in the field). Players are categorized by the position they play in the field. The pitcher is the person who throws the ball. The catcher is the person who receives the ball. Basemen can be first, second, or third basemen, and they predominately position themselves around these bases. The “shortstop” plays between the second and third basemen. Outfielders can be positioned in the left, center, or right part of the field and play the farthest away from the pitcher. The batter is on the opposite team. A runner is a batter who has successfully hit the ball and is on one of the initial three bases.
More than 2.6 million persons with baseball- or softball-related injuries presented to emergency departments across the United States over a span of 6 years. The majority of injuries occur by nonhuman contact (45%) or no contact at all (42%). Accordingly, collisions with high-velocity balls, bats, bases, outfield walls, and the ground play a major role in the injury patterns seen in the sport. Secondarily, the routine acts of running, throwing, and pitching also can be deleterious.
A study of Major League Baseball players showed that pitchers sustain more injuries than outfield players, with a larger percentage of their injuries affecting the upper extremity. Outfielders proportionately had a greater number of lower extremity injuries. Among all players, upper extremity and lower extremity injuries accounted for 51.4% and 30.6% of all injuries, respectively. Injuries to the spine and core musculature and other illnesses accounted for the remainder of injuries. These statistics are also supported at the collegiate level.
Given that pitchers are most commonly injured and upper extremity injuries are proportionately higher, it is important to understand the throwing motion and the forces applied to musculoskeletal structures during the phases of motion. A throwing motion begins with cocking of the arm and shoulder, followed by acceleration and ending with the follow-through. Maximum forces occur in the acceleration phase. Biomechanical studies have demonstrated forces up to 500 N at the lateral radiocapitellar joint and velocities as high as 3000 degrees per second during the late cocking and acceleration phase. These forces have a direct impact on some of the upper extremity injuries seen in the sport.
Tendinosis and tendinitis of the rotator cuff and proximal biceps tendon are common overuse baseball injuries. Maximal stress to the rotator cuff occurs during the follow-through phase of throwing, because this group of muscles decelerate the arm. The superior labrum anterior to posterior (SLAP) tear is another shoulder condition that is frequently encountered. The superior labrum is an attachment site for the long head of the biceps tendon. Consequently, repeated traction of the biceps tendon with overhead throwing can lead to SLAP tears.
The throwing motion in baseball involves large valgus forces and rapid elbow extension. This combination produces tensile forces on the medial structures of the elbow, shear stress on the posterior elements, and compression forces on lateral structures. This combination is known as the “valgus, extension overload syndrome” and explains the pathophysiology behind most throwing elbow disorders.
Medial epicondylitis is one such injury that results from recurrent valgus forces during the acceleration phase of the throw. Another is an ulnar collateral ligament (UCL) sprain or tear. The anterior fiber bundle of the UCL is the primary restraint to valgus forces applied to the elbow from 30 to 120 degrees. These fibers are subjected to very high tensile forces during the acceleration phase, which can lead to failure. Athletes usually present with sharp medial elbow pain with throwing, as well as decreased throwing distance and velocity.
Injuries to the hand can occur while sliding head first, batting, fielding, or pitching. Contusions, sprains/strains, and tendinopathies are most common; fractures, dislocations, and tendon ruptures are less frequently encountered. Tendon ruptures typically result from the ball striking an exposed hand. Tendinopathies are a consequence of batting technique, pitching grip, and failure as a result of repetitive stress.
The lower extremity is the most frequently injured body part among fielders. These injuries account for a significant portion of all baseball injuries—approximately 32% at the collegiate level and 30.6% at the professional level. Upper leg muscle and tendon strains are the most common lower extremity injury, with hamstring strains being the most common. Internal derangement of the knee and ankle and foot sprains make up the other large numbers of lower extremity injuries. Most of these injuries occur during sudden sprints, while sliding, or while attempting to catch a ball in the outfield.
It is estimated that 5 million children younger than 14 years of age participate in baseball every year in the United States. The overwhelming factor leading to injury in this age group is overuse, and an important consideration in the young thrower is that of the developing physes. It is therefore imperative that all physicians dealing with young throwers be aware of the bone maturation process, particularly for the shoulder and elbow, and maintain a high index of suspicion for injuries to the physes. The powerful throwing forces exerted on these vulnerable structures can lead to widening, demineralization, and fragmentation of the epiphyseal plate. The elbow is most commonly affected, with a spectrum of pathology that includes an apophysitis or avulsion of the medial epicondyle and osteochondritis desiccans of the capitellum or radial head. In the shoulder, an epiphysiolysis of the proximal humerus may develop. Collectively, these conditions are colloquially known as “little leaguer’s elbow” and “little leaguer’s shoulder.”
The goal of basketball is to score points by shooting a ball through a basket mounted approximately 10 feet high. Basketball can be played in a formal team setting or in “pick up” leagues with various numbers of players on each side. Most league basketball is a formalized sport with established rules, on-site referees, and penalties for infractions. However, most basketball games played in neighborhoods are unregulated, unsupervised, and informal.
The goal of the game is to score more points than the opposing team by passing the ball through a basket. The team with the ball is termed “on offense,” and the team without the ball is “on defense.” Basketball is similar to soccer and hockey insofar as possession of the ball can quickly change and the offensive team can quickly become the defensive team. To move the ball down the playing field (“court”), the ball must be either dribbled or passed from player to player.
Five players from each team are on the court—the point guard, shooting guard, small forward, power forward, and center. Centers are generally the tallest players and usually are positioned near the basket with the goal of opening for a pass, shooting, blocking defenders, and opening other players up for driving to the basket for a point. Because of their height, centers are expected to get some offensive rebounds and keep opponents from shooting by blocking shots and passes in the key area. Forwards are usually the next tallest players on the team. Although a forward may be called upon to play under the hoop, he or she also may be required to operate in the wings and corner areas. Small forwards are responsible for getting free for a pass, taking outside shots, driving for shots, and rebounding. The point guard is the “playmaker” of the team. The point guard is potentially the shortest (and fastest) player and usually excels at dribbling, setting up plays, and passing. It is the point guard’s job to bring the ball down the court and set up offensive plays. The point guard also needs to be able to drive to the basket and shoot from the perimeter. The shooting guard takes a high volume of long-range shots and guards the opponent’s best perimeter player on defense. Guards are responsible for stealing passes, contesting shots, and preventing drives to the hoop.
A significant number of studies have documented injury patterns among various groups in basketball. Basketball has consistently been one of the leading sports activities associated with injuries, with estimates of up to half a million physician visits per year. The most commonly reported injuries in basketball are ankle sprains, finger sprains/fractures, knee injury (traumatic and overuse), facial lacerations, dental injury, and concussion.
Inversion ankle sprains are the most common basketball-related injury. In crowded situations under the net, it is easy to land on an opponent’s foot in a plantar-flexed and inverted position. Use of ankle braces has been studied, with some evidence indicating that lace-up braces may reduce the incidence but not the severity of injury ; however, research showing a strong link between prophylactic bracing and injury prevention is lacking. Some promising studies have shown a decrease in the incidence of ankle sprains with a preparticipation balance training program.
Anterior cruciate ligament (ACL) tears are relatively common in basketball as a result of the quick deceleration and change of direction required in the sport. Female players have a relatively higher risk for noncontact ACL injury. Postulated mechanisms for this increased risk include increased dynamic valgus and high abduction load. Injury prevention programs focus on improving strength, core stability, balance, and biomechanics of the lower extremity.
The patellar tendon and Achilles tendon are both vulnerable to overuse tendinopathies given the repetitive jumping and eccentric loads sustained by these areas. The most common overuse injury in basketball is patellar tendinitis, or “jumper’s knee.” In junior basketball, the prevalence has been shown to be as high as 10%. Risk factors for jumpers knee have included high jumping, deep knee flexion during landing, and valgus strain during the eccentric load phase of landing. Acute Achilles tendon ruptures are not uncommon in older athletes.
Injuries to the hand are very common in basketball. Most injuries (>90%) involve sprains and volar plate injuries of the proximal interphalangeal (PIP) and metacarpophalangeal joints. Dislocations at the PIP joint are common from direct ball contact with axial load. Players are also at risk for avulsion of the extensor digitorum when the ball creates an axial load through the fingertip (“mallet finger”) and avulsion of the flexor digitorum profundus when the finger is caught on an opponent’s jersey or on the rim during a slam dunk (“jersey finger”). Boutonnière deformity can result from rupture of the extensor tendon central slip; early recognition of this condition is important. Gamekeepers’ injuries to the thumb usually occur as a result of a fall to the floor or an extension load to the thumb while blocking an opponent.
Male players are more likely to sustain facial lacerations and dental injuries than are female players. Dental injuries include fractures, avulsions, and oral lacerations. Ocular trauma is common from contact with opponents’ fingers or elbows and can result in corneal abrasions, retinal detachments, hyphemas, lacerations, contusions, and fractures. Nasal fractures may occur, either from a blow by the opponent’s elbow or head to head contact. Protective mouth gear is often worn by players.
Basketball is a contact sport and as such creates a risk for concussion, particularly under the basket, where players have an increased risk for direct blows and falls. A prior history of concussion is a predictor of repeat injury and should be evaluated during a preseason examination. Every sport concussion should be managed on site and have medical clearance before return to play.
Back pain may occur as a result of repetitive axial loading. This may lead to an increased risk for spondylolysis, particularly in the the younger athlete.
Basketball is classified as a high-intensity sport with moderate static and high dynamic demands. It is estimated that up to 35% of sudden deaths in sports occur in basketball; the majority of these deaths are due to cardiovascular causes, including hypertrophic cardiomyopathy and, less commonly, coronary anomalies, arrhythmias, and aortic root anomalies associated with Marfan syndrome. The high prevalence of tall people in basketball and the high prevalence of Marfan syndrome in tall people creates a possible cause for concern in the sport. Preparticipation screening with a cardiac-specific history and physical is advised, although it may be of limited value for many cardiac anomalies. A 12-lead electrocardiogram and an echocardiogram may provide more information, but cost-effectiveness is an issue for mass screening, and these tests currently are not recommended as routine screening.
Boxing is a combat sport in which two opponents engage in a fight using gloved fists. A match is won either when one competitor is declared physically unable to continue by the referee or by the decision of a panel of judges after the last round. Boxing has two main divisions: amateur and professional. Most epidemiologic studies focus on injuries in amateur boxing. By its inherent nature, boxing predisposes participants to serious injury. It continues to be one of the most controversial sports with regard to safety because injuries are caused by intention rather than by accident.
Punches can only be thrown above the waist, and thus injuries predominantly involve the head and upper limbs. A study of professional boxers found an overall incidence of 17.1 injuries per 100 boxer matches or 3.4 per 100 boxer rounds. The most common injury was facial laceration, which accounted for more than 50% of the total injuries. Another study of boxers with injuries who presented to an emergency department found an injury rate of 12.7 per 1000 participants, with hand fractures being the most common injury. In this study, punching-bag injuries accounted for 36.8% of the total number of injuries. When fights lost by a technical knockout or knockout (i.e., neurologic injury) were included, nearly two thirds of all professional fights resulted in injury.
Direct trauma to facial structures accounts for the majority of boxing injuries, with lacerations and epistaxis being the most common. Although epistaxis is often easily controlled, important considerations for the ringside physician include the presence of posterior bleeding, acute fracture, pulsatile arterial bleeding, or heavy venous bleeding. All boxers with epistaxis should be examined after the bout for the presence of a septal hematoma.
Ocular injuries in boxing are common and can be serious. The injury often depends on the direction of contact. Direct impact can result in soft tissue injury to the lids and corneal abrasions. Angled blows can damage deeper ocular structures and occasionally result in retinal detachment and hyphema. Any black eye should prompt a detailed examination. The presence of restricted movement, enopthalmosis, eyelid edema, ptosis, diplopia, or bony step-off deformity could signify the presence of an orbital blowout fracture.
Injuries to the ear, mouth, and jaw are seen less commonly, with each accounting for 1% to 2% of total injuries. Ringside physicians should be familiar with the initial management of auricular hematoma, mandible fracture, temporomandibular dislocation, and tooth avulsions.
The majority of musculoskeletal injuries involve the hand and wrist. In one study it was found that 39% of musculoskeletal injuries involved the thumb, 35% involved the base of metacarpals, and 26% involved the phalanges and metacarpals (excluding the bases). The majority of injuries are soft tissue sprains and strains, but fractures are not uncommon.
The most common fractures involve the metacarpal shaft, the fifth metacarpal neck (boxer’s fracture), the first metacarpal base (Bennett fracture), and the scaphoid. Many of the fractures encountered in boxing will require surgical management. Injury to the metacarpophalangeal joint (boxer’s knuckle) also may warrant surgical attention.
Soft tissue injuries in the hand also can be serious and may require urgent medical attention. Specifically, boutonnière deformity, mallet finger, and interphalangeal dislocations often necessitate reduction and splinting.
Concussion is the most common neurologic condition encountered in boxing; however, neurosurgical emergencies such as an acute subdural hematoma can occur. Even though concussion is such a common occurrence in professional boxing, very few studies have been conducted to examine the actual incidence of concussion and neuropsychiatric consequences. More attention is now being given to chronic traumatic encephalopathy, which results from repeated concussive blows. One study in which retired boxers from the British Boxing Association were examined documented that 17% had lesions to the central nervous system.
Figure skating is a unique combination of athleticism and artistry on ice. Figure skating includes four major disciplines: singles skating, pairs skating, ice dance, and synchronized skating. There is also an adult skater competition circuit. In singles skating, the individual skater performs different jumps and spins with intricate footwork connecting the different elements. In pairs skating, a male and female skater perform jumps and spins separately and in tandem, along with overhead lifts and throws. The major components of ice dancing are intricate footwork with a focus on deep edges, speed, and closeness of the two skaters. Specific rules are in place in terms of lifts and how long the skaters can be separated. Synchronized skating is a team sport. A number of skaters ranging from 8 to 24 per team skate together in different formations, performing complex footwork simultaneously.
Most figure skating injuries, both acute and chronic, occur in the lower extremity and lower back. The leather boots used by figure skaters have become stiffer over the years to accommodate the impact of increasingly difficult jumps. It has been hypothesized that the increased stiffness of the boot has contributed to a weakening of the ankle and thus an increased number of skating injuries of the foot and ankle. Bursitis is the most common skating problem related to the foot and ankle and is most often seen along the medial malleolus.
Other foot and ankle issues include pump bumps from friction of the boot along the heel; Achilles tendinitis; subcutaneous fat impingement, which can occur between the fibula and the boot rim, creating painful soft tissue swelling along the lateral supramalleolar region ; anterior tibialis and toe extensors tenosynovitis from where the laces tighten (i.e., lace bites) ; and stress fractures in the foot (most commonly the metatarsals and navicular bone).
Knee, leg, and hip conditions can range from acute muscle and ligamentous injuries to chronic tendinopathies (e.g., patellar tendinosis), joint laxities and irritations (e.g., patellofemoral syndrome and snapping hip), apophysitis (Osgood-Schlatter disease), and stress fractures.
Because of the arching and high-impact nature of the sport, spondylolysis (i.e., stress fracture of the pars articularis) can be a common cause for back pain in skaters, and female skaters are at an increased risk for this condition. Other back issues include facet joint irritations, hypomobility/hypermobility issues, and degenerative disease.
Pairs and dance skaters have a higher risk of collision during practice and warm-ups compared with singles skaters, which can lead to lacerations, fractures, and head injuries. These skaters also encounter shoulder and wrist problems as a result of the lifting and throwing elements in their discipline. Synchronized skating can be quite dangerous because of the number of skaters on the ice and the tight formations and maneuvers that they perform. A domino effect often occurs when one skater falls, creating a high risk for lacerations, finger amputations, fractures, and head injuries.
American football is a sport played between two teams of 11 players (in the United States) or 12 players (in Canada). The objective is to score points by either advancing the ball into the “end zone” of the field (i.e., scoring a “touchdown”) or kicking the ball through two raised “goal posts” (i.e., a “field goal”). The team with the ball is considered on offense and the team without the ball is on defense. In the United States, the offense has four opportunities (“downs”) to advance the ball at least 10 yards to gain a new set of downs. In Canada, only three downs are allowed. The goal of the defense is to tackle the player with the ball and bring him to the ground to end a play (or “down”). Unlike basketball or soccer, players typically play only offensive or defensive positions. Each position is highly specialized with a set of unique injuries that may occur.
Offense includes seven groups of players. The quarterback is a single individual who is the leader of the offense. He receives the ball from the center and can either throw the ball to another player, hand the ball to another player, or run with the ball himself. The offensive line is a group of five players who protect the quarterback and includes the center, who “snaps” the ball to the quarterback to start a play (or down). Running backs stand behind the quarterback and may receive the ball to run it forward. Wide receivers stand far away from the offensive line and run down the field to catch a pass thrown by the quarterback. A tight end is positioned next to the offensive line and can play either like an offensive lineman or a wide receiver.
Defense includes three groups of players. The defensive line is a series of three to six players who attempt to tackle the quarterback or running backs. The linebackers are a group of three to four players who stand behind the defensive line and may either attempt to tackle the quarterback or running backs or cover the wide receivers and prevent them from catching a thrown ball (“pass”) from the quarterback. The defensive backs (“cornerbacks” and “safeties”) stand furthest back from the defensive line and block the wide receivers.
Lastly, football includes a third group of players termed the “special team.” They predominately participate in plays that involve kicking the ball. These plays typically occur either at the start of the game, when the team has failed to advance 10 yards after three downs, or after the team has scored a touchdown and is kicking the ball through the goal posts. The punter typically kicks the ball a long distance when the team has failed to advance 10 yards. The place-kicker typically kicks the ball for field goals or to start the game by kicking the ball to the other team.
American football is the most popular contact sport in North America, with more than 2 million athletes participating each year in the United States alone. The inherent nature of any contact sports is the propensity for traumatic injuries. In addition, like other athletes, football players are susceptible to noncontact and repetitive stress injuries. The injury rates in football vary by age, level of play, and position. Lower extremity injuries account for half of all injuries, whereas the upper extremity accounts for a further 30%. The most common types of injury are sprains and strains (40%). Contusions (25%), fractures (10%), dislocations (15%), and concussions (5%) account for the remainder of the injuries.
Head and Neck Injuries
Getting a true sense of the incidence of concussions in football is difficult because of underreporting and, until recently, a lack of a standardized method to assess these injuries among coaches, trainers, and other medical staff. Concussions are estimated to account for about 5% of all football injuries. The rate of concussion varies by level of competition, with 0.47 per 1000 athlete exposures in high school students and 0.61 among collegiate athletes. Most of these concussions occur as a result of head contact during tackles and blocking plays.
Cervical spine injuries are the most common cause of catastrophic injury in football. Fortunately, because of rule changes modifying tackling and blocking techniques, the incidence of cervical spine injuries (especially the catastrophic variety) has decreased. Injuries to the cervical spine encompass a spectrum of ligament or soft tissue damage, fractures, and neurologic impairment. Fractures vary from stable to unstable fracture-dislocations and are typically the result of axial load applied to a flexed or extended spine.
One of the more commonly encountered neurologic injuries is a neurapraxia of the brachial plexus or the cervical spine nerve roots, frequently referred to as a “stinger.” It is estimated to occur in 50% to 60% of collegiate football players during a 4-year career. The injury is characterized by unilateral lancinating pain from the neck down the arm, with symptoms typically lasting from seconds to hours. The two common mechanisms of injury are a combination of neck hyperextension, lateral flexion, and axial load or a direct blow to the brachial plexus. Other neurologic injury also can occur from disc prolapse or herniation as a result of repetitive or acute trauma.
Thirty percent of all football-related injuries involve the upper extremity, with the shoulder being the most commonly affected joint (11%). The player in the quarterback position is most susceptible to shoulder injuries that can result from the throwing motion or overuse or as a result of trauma sustained during tackles. The spectrum of shoulder injuries includes but is not limited to acromioclavicular/sternoclavicular joint separations, acute rotator cuff pathology and repetitive strain injuries, subluxations/dislocations, and fractures.
Further down the arm, “wrist sprains” are another condition that is frequently encountered. A study of NFL players found that this type of injury represented 19% of all injuries to the wrist, forearm, and elbow. Most of these injuries occurred during blocking or tackling plays and included ligamentous or joint instability injuries. Fractures of the forearm and wrist were the second most common type of injury and usually resulted from impact with the ground or other players.
Lower extremity injuries are the most common type of injury in football. Injuries such as fractures, ligament disruption, and contusions can result from direct contact during tackles. Noncontact or atraumatic injuries may be associated with cutting, pivoting, sprinting, and heavy weight training. The knee (20%) and ankle (18%) are the most commonly injured parts in the lower extremity.
Different positions require specific skill sets that predispose the athletes to a particular type of injury. For example, thigh muscle strains are commonly seen in defensive backs, who have to make rapid transitions, from backpedaling to sprinting in on a tackle. Foot and ankle injuries are frequently seen in linemen because large bodies often fall on their planted legs. These forces can result in ankle sprains or dislocations and fractures of the ankle or metatarsal bones.
Knee ligament and meniscus injuries are particularly common in running backs, who do a lot of cutting and pivoting and are susceptible to tackles by much larger linemen. Damage to the ACL is the most common knee injury, which results in significant loss of playing time. For example, between 1987 and 2001, ACL reconstruction was the third most commonly reported procedure among NFL players. Most ACL tears result from a player decelerating and pivoting on a partially extended knee or from a direct blow that produces a valgus and external rotation force on a planted leg.
Finally, environmental factors also may play a role in the types of injury encountered in the sport, with “turf toe” being a prime example. Turf toe is a sprain to the plantar capsule at the first metatarsophalangeal joint as a result of a forced hyperextension. A combination of playing on artificial turf and wearing flexible cleated shoes places football players at risk for this injury. Artificial turf has a high friction coefficient and typically loses its shock absorption over time, which increases the risk of the forefoot becoming fixed to the playing surface and therefore the risk of hyperextension injuries.
Golf is typically an individual sport in which players use “clubs” to hit balls into holes in as few strokes as possible. Golf is played on a “course” with either 9 or 18 holes. It typically takes between three to five shots (“strokes”) to place the ball in the hole.
Although it is considered a low-impact sport, golf is associated with a significant number of injuries, with an annual injury rate of roughly 40%. The entire body is used to execute a golf swing in a complex and coordinated movement, which can result in injury when this movement is repeated frequently. Poor swing mechanics and overuse are frequently associated with injury. Traumatic injuries also may result from hitting the ground with the club, collision injuries entailing a club or ball, or jumping or falling from carts. Recreational golfers are more likely to experience traumatic injuries and injuries resulting from poor mechanics, especially at ball impact. Overuse injuries predominate in professional golf and tend to be due to short periods of intense play or a high number of practice hours.
The most commonly injured part of the body is the lower back, followed by the elbow, the wrist and hand, and the shoulder. Lower limb injuries are far less common but include trochanteric bursitis and aggravation of underlying knee osteoarthritis. Other less common injuries include rare but serious head and eye injuries from impact with a club or ball, stress fractures, environmental issues such as skin cancer, heat illness, or lightning strikes, and cardiovascular insufficiencies.
Lower Back Injuries
The lower back, which is reported as being the most common injury site among golfers, is subject to large ranges of forces and motions as a result of the mechanics of the golf swing. The forces that occur during a swing may be categorized as downward compression, side to side bending, and back to front shearing, with peak compressive load up to eight times one’s body weight. The result is an increased risk of strains, disc herniation, and facet arthropathy. Symptoms of lower back pain are predominantly reported as right-sided (the lead side for right-handed players), and usually occur from ball impact until follow-through and after practice sessions. A study of professional golfers compared with age-matched control subjects showed increased right-sided osteophyte formation at L3/L4 and significantly higher rates of facet joint changes in L3/L4 and L4/L5 in professional golfers.
Wrist and Hand Injuries
Overuse sprains and strains of the wrist are reported among golfers. Examples include pain in the extensor carpi ulnaris (caused by early uncocking of the wrist in the downswing) and subluxation of the fingers (thumb) or tenosynovitis of adductor tendons. The most common mechanism of injury, however, comes from the sudden decrease in movement of the accelerating hand and wrist at impact, especially when hitting the ground or objects other than the ball. In golfers, this mechanism can result in flexor carpi ulnaris injury or can cause fractures of the hook of hamate.
Elbow injuries are common in golfers, especially in amateur and female golfers. Injury to the common flexor bundle at its attachment to the medial humeral epicondyle is often referred to as “golfers’ elbow”; however, five times more golf-related injuries occur at the extensor attachment to the lateral epicondyle. Medial epicondylitis most often occurs in the lagging arm after rapid deceleration or forceful resistance from hitting the turf with the head of the club. Overuse is the most common mechanism for lateral epicondylitis and occurs with equal frequency in the leading and lagging arm.
In most cases, shoulder injury in golf is in the leading arm and is related to overuse due to excessive shoulder external rotation at the beginning of the swing and internal rotation at the end of the swing. Pain in the shoulder may be a result of acromioclavicular dysfunction, subacromial impingement, rotator cuff tendinitis or tear, posterior glenohumeral instability or arthritis, or instability resulting from isolated labrum tears.
Artistic gymnastics has 4.8 million participants in the United States at the recreational, competitive, and elite levels. It is the most popular sport for children younger than 13 years; 48% of children who play sports participate in gymnastics. Women compete in four events: vault, uneven parallel bars, beam, and floor exercises. Men compete in six events: vault, high bar, parallel bars, rings, pommel horse, and floor exercises.
Floor exercises consist of a wide range of tumbling and acrobatic movements on a 12 m 2 mat. Routines on the beam involve daring exercises performed 1.25 m above the floor on a 5 m by 10 cm beam. In both events, alteration occurs between upper and lower extremity support, resulting in high impact, axial compression, and rotation to joints of the body. This scenario is also seen in the vault, with the athlete launching from a springboard after an approach run, then pushing off from the vault table with the upper extremities. An acrobatic maneuver is performed prior to landing on both feet in the landing area. Acrobatic dismounts and landings from the rings, horizontal bar, beam, and vault table can lead to acute lower extremity injury. The change of grip on the horizontal bars and uneven bars with release and regrasp of the bar can predispose an athlete to acute injury. For the male gymnast, the rings and parallel bars involve a combination of swinging movements and handstands that are physically demanding on the upper extremities. The pommel horse has two handles, and the athlete performs circular and pendulum swings, leg circles, scissor movements, and handstands. For competitive gymnasts, training starts at a young age and involves many hours of training, which can increase the risk of overuse injuries. Areas of particular concern are the spine and growth plates of the wrist.
Injury incidence ranges from 1.4 to 3.7 injuries per 1000 participation hours. The injury rate in competition is two times higher than in practice. However, most injuries occur during practice because the exposure time is greater. Both acute and overuse injuries occur in gymnastics. In both male and female gymnasts, 60% of injuries are acute. The parts of the body that are particularly affected are the shoulder, wrist, elbow, lower back, knee, and ankle. Common injury types are strains, sprains, contusions, and less commonly fractures (acute and stress). Concussions make up 2.3% of injuries in practice and 2.6% of injuries in competition. In one study of elite and subelite female gymnasts from ages 11 to 19 years, 12.3% of injuries were to growth plates.
The lower extremity is the most common area of injury in female gymnasts, accounting for 53% of injuries in practice and 69% of injuries in competitions. In competition, 20% of injuries are internal derangement of the knee (e.g., ACL tear, medial collateral ligament [MCL]/lateral collateral ligament sprain, or meniscal tear), and 16.4% of injuries are ankle sprains. These injuries most often occur during floor routines and dismounts. Chronic injuries of the knee include patellofemoral syndrome, patellar tendonitis, and Osgood-Schlatter disease. Foot injuries include calcaneal apophysitis, foot pad contusion, sesamoiditis, planter fasciitis, and fracture (acute and stress).
Upper extremity injuries are the second most common area of injury in female gymnasts and the most common area of injury in male gymnasts at 54%. In male gymnasts the most common site is the shoulder. Shoulder injuries include rotator cuff impingement, strain, and tendinosis, labral tear, and glenohumeral dislocation. The most common sites of upper extremity injury in female gymnasts are the wrist and elbow. The elbow can be affected by acute injuries (i.e., ulnar collateral ligament sprains, fractures, and dislocations) and chronic injuries (i.e., medial epicondyle apophysitis and osteochondritis dissecans of the capitellum). Repeated loaded extension and rotation of the wrist in the gymnast predisposes him or her to a number of wrist injuries. One of the most frequent injuries in the skeletally immature gymnast is a distal radial physeal stress injury, which has been reported to occur at a rate of 1.9 to 2.7 injuries per 100 participant seasons. A complication can be arrest of the distal radius physis growth. A wrist brace to control extension can be beneficial when returning to training.
Lower back pain is a common complaint of gymnasts, with a prevalence ranging from 25% to 85%. In gymnastics the lumbar spine undergoes repeated flexion, hyperextension, rotation, and compressive and distraction loads (in hanging events) during vaults, dismounts, and acrobatic maneuvers. Gymnasts have a high prevalence of spondylolysis, which is thought to be related to the repetitive hyperextension and rotation. Careful evaluation of all back pain with consideration of the differential diagnoses of spondylolysis, disk pathology, and Scheuermann disease with appropriate imaging is imperative.
Ice hockey has been a popular sport in colder climates since the first organized game was played in Montreal, Canada, in 1875, but it is gaining worldwide popularity. Players range in age from 4 years to older than 80 years. Hockey leagues vary in the level of competition, from recreational to professional. The amount of body contact also ranges from none to sanctioned body checking and occasional fist fighting. The number of women in hockey has increased, and when played by women, the game does not include body checking or fighting at any level.
Ice hockey is played on ice rinks with rounded corners. The size varies but is based on standard international measurements of 61 × 30 m (200 × 98 ft) and North American specifications of 61 × 26 m (200 × 85 ft). The rink is surrounded by boards made of wood and plastic that are 1.02 to 1.2 m (40 to 48 in) and further topped with Plexiglas and netting to allow spectators to watch the game with limited risk of injury. The Plexiglas does not cover the boards in front of the players’ benches. Each team has six players on the ice at once: one goaltender, two defenders, and three forward players. All of the players wear skates, helmets, and protective equipment, with the goaltenders being more substantially padded. The players skate up and down the ice and use either wooden or composite sticks with a blade on the end to pass and shoot a frozen vulcanized rubber “puck” that is 25 mm (1 in) thick and 75 mm (3 in) in diameter; the puck is shot at a 1.22 m × 1.83 m (4 ft × 6 ft) net protected by the goaltender. A goal is scored when the puck crosses the goal line situated between the standards of the net. The puck can move as fast as 195 km per hour (110 mph), and the skaters can move as fast as 45 km per hour (28 mph). Although the goaltender generally plays the entire game, the players’ lines change every 30 to 90 seconds, with each team having between two to four lines. The hockey game has three periods, each lasting between 10 to 20 stop time minutes, depending on the level of competition.
Injuries in hockey are common and are reported to be as high as 16 injuries per 1000 athlete exposures during games and 1.96 injuries per 1000 athlete exposures during practice. Injuries occur more often in tournaments compared with regular season games and in preseason compared with regular season practice. Injuries peak in the 12- to 17-year age group and show a spike during the first year that body checking is introduced. More competitive leagues have a higher injury rate than do house leagues, and body checking is associated with an increased risk of injury. Women have a similar injury rate as non–body-checking leagues at four to seven injuries per 1000 athlete exposures. The types of injuries are similar in all ice hockey leagues, although the frequency varies depending on level of competition, whether body checking is allowed, and the amount of facial protection mandated. Head and neck injuries account for 20% to 30% of hockey injuries. Concussions are the most common injury, especially among women. Concussion awareness is rapidly increasing, and management strategies are evolving. Rule changes at all levels of play are being instituted with the hope that the rate of concussion will diminish. Similarly, spinal injuries decreased dramatically once hitting from behind was eliminated. Facial lacerations, contusions, globe injuries, and dental injuries are also seen, especially when full facial protection is not worn. Rarely, catastrophic neck vessel lacerations from skate blades and tracheal disruption from contact with the puck occur.
Upper extremity injuries account for 8% to 20% of injuries, with the most common being acromioclavicular separation and glenohumeral dislocation. Sprains, strains, and fractures are also common in the wrist and hand. Injuries to the torso include rib fractures and lower abdominal and groin muscle strains. An injury unique to hockey called “slapshot gut” but similar to “sports hernia” described in other sports involves injury to the external oblique muscle and ilioinguinal nerve. Lower extremity injuries account for 20% to 30% of injuries. The most common are hip pointers, quadriceps contusion, and skate bite, which is tendonitis of the ankle extensor tendons due to compression by the tightly laced skate. Medial collateral ligament sprain is the most common knee injury. ACL injuries occur, but not commonly. Ankle sprains and syndesmosis injuries usually occur as a result of a rut in the ice or direct impact with the boards after a fall.
Rowing as a competitive sport dates back several hundred years. It is one of the first sports to be part of the modern Olympics. Rowing is now enjoyed not only by amateur athletes of international level but also by more senior athletes through Masters competitive and recreational programs. An understanding of the basics of the sport and the mechanics of the rowing stroke is paramount in the assessment of rowing injuries.
Injuries differ depending on whether the athlete is rowing on water or training on stationary ergometers and also depend on the type of rowing. Rowing can be divided into sweep rowing and sculling. Sweeping uses one oar per rower (either on the starboard or port [left and right, respectively]). Sculling, on the other hand, uses two oars per rower. In competition, the rowers are divided between heavyweight and lightweight categories; the cutoff weight is 130 lb for women and 160 lb for men.
The sport of rowing encompasses both aerobic (mainly) and anaerobic exercise; the Olympic event takes place over a 2000-m course. Subsequently, it carries undeniable benefits for cardiovascular health but also subjects its athletes to specific injuries, which are for the most part chronic in nature. Overuse, changes in technique or equipment, and improper recovery are the main culprits for injuries.
Lumbar Spine Injuries
Back injuries are the most common problem in rowers (consisting of 15% to 25% of all rowing injuries). During the stroke, the back serves to transmit force from the legs to the oar. The compression load on the back can be up to 4.6-fold the rower’s body mass. The excessive and repetitive flexion (and twisting in sweep rowing) at the “catch” of the rowing stroke coupled with fatigue from long rowing sessions and muscle imbalance are often to blame. Extensive ergometer training is also responsible for back problems. The most common back issues encountered in rowers are disc herniation and other discopathy, facet joint injury, and sacroiliac joint dysfunction.
Rib stress fractures are a cause of concern for the rowing population because they account for most of the time lost from training and competition. Rib stress fractures occur at a rate of 6.1% to 12.0% (equally affecting scullers and sweep rowers) and usually are found in the fourth to eighth ribs anterolaterally. The exact incidence is unknown because these injuries are often underdiagnosed or misdiagnosed. The mechanism of injury involved remains unclear and appears to be multifactorial. Intrinsic and extrinsic factors have been mentioned: repetitive muscle contractions (especially involving the scapular retractors and abdominals), joint hypomobility, low bone mineral density—amenorrhea, excessive training, poor technique, and equipment problems. Of note, the serratus anterior muscle, which previously was believed to be part of the etiology of rib stress fractures, seems to have a protective role.
Costochondritis (from rotation of the thoracic spine at the catch position in sweep rowing), costovertebral joint subluxation, and intercostal muscle strain account for some of the remainder of rib injuries in rowing.
Injuries to the forearm and wrist are relatively common in rowing and occur as a result of excessive wrist motion and poor technique when feathering the oar during the recovery phase. The most commonly seen injuries are intersection syndrome (i.e., tenosynovitis in the first and second dorsal compartments of the wrist), chronic compartment syndrome, lateral epicondylitis, de Quervain tenosynovitis, and tenosynovitis of the extensors of the wrist (“sculler’s thumb”). The latter is the only injury characteristic of rowers and can be found in about 10% of rowing athletes.
Ligamentous and meniscal injuries occur rarely in rowing, but patellofemoral pain is a common complaint. Two instances during the rowing stroke are predisposing: (1) at the catch, with the knees in full flexion, or (2) at the finish, at which point the knees are prone to pop up early or buckle. Iliotibial band friction syndrome also can be found frequently, especially in rowers with varus knee alignment (symptoms usually are felt at the catch with knees in full flexion).
Other problems can arise from pressure wounds, calluses, and blisters. The female athlete triad and overtraining syndrome are also two important issues encountered in the sport of rowing.
Rugby is a team sport traditionally played by 2 teams of 15 players each (called a rugby union) on a field of grass or artificial turf not greater than 144 m long and 70 m wide. Play is continuous except for stoppage for a rule infarction and is divided into two 40-minute halves. Rugby includes eight forwards, whose main role is to contest the ball, and seven backs, whose main role is to run the ball and score points. The ball is advanced mainly through running, although kicking occurs in certain situations. The ball can only be passed sideways or backward. Any player can receive and pass the ball, and several passes are allowed. The forwards often create a pyramid formation to engage the opposite team in a “scrum” for possession of the ball after the play has been stopped. Rucks and mauls occur when a player has been tackled and his/her teammates create a platform to protect the ball while the opposing team tries to crash through the platform and access the ball. Line-outs consist of two players being boosted up in the air by their teammates to take possession of the ball after it has gone out of bounds. Protective gear such as that seen in American football is not allowed in rugby. The only protection players are allowed include thin shoulder and chest pads and scrum caps.
A review of English professional rugby union players found that lower extremity injuries were most common, although upper extremity injuries were more severe. Acute injuries occur more often, but recurrent injuries keep players out of the sport longer. The most common injuries include muscle and tendon injuries (50%), followed by non–bony joint and ligament injuries (41%). Collisions, tackles, and scrums are most often associated with rugby injuries.
Knee injuries account for the most number of days lost from play and practice; MCL injuries are the most common, but ACL injuries are the most serious.
Although no significant difference in injury rate or severity is found between artificial turf and grass, there seems to be trend toward a higher incidence of ACL injuries on artificial turf.
Hamstring injuries are also common because of the stop and go, sprinting, sudden changes of direction, and kicking nature of the sport. Players in the back position are at higher risk for both knee and hamstring injuries.
Shoulder injuries follow knee injuries in causing days lost from practice and play ; 97% of shoulder injuries occur during contact, with tackles causing the most injuries (43%). Acromioclavicular (AC) joint injuries are the most common shoulder injuries (32%), whereas shoulder dislocations are the most severe and recurrent injuries (62%).
Spinal injuries in rugby can be both noncatastrophic and catastrophic. In a New Zealand retrospective study that surveyed spinal injuries in rugby over the course of 20 years, 83% of spinal injuries occurred in forwards and 17% in backs. Overall, players are more likely to sustain a cervical injury during matches than in training, with inexperience being a large risk factor. Fifty-eight percent of c-spine injuries occur during the scrum, where the generated forces on engagement can reach up to 1.5 tons, far exceeding the forces needed to cause vertebral body compression or ligamentous injury. The hooker (i.e., the person at the tip of the pyramid) is most vulnerable. All scrum members (forwards) have their necks slightly flexed, putting them at risk of axial compression as they engage, but the hooker also has both arms wrapped around other players’ shoulders, limiting his or her ability to adjust his or her body in reaction to an improper engagement. Lumbar spine injuries seem to occur more often during training season, especially with weight training. Forwards are more likely to sustain this type of injury.
In a prospective study in which investigators looked at injuries sustained by elite Australian rugby union players between 1994 and 2000, it was found that head injuries were mainly closed injuries, falling into the category of mild traumatic brain injuries. Players at risk include inexperienced players (i.e., persons who have played rugby for 0 to 3 years), as well as very experienced players (who have played >8 years). This latter group’s increased risk is believed to be due to the increased intensity, aggressiveness, and speed of the game, leading to increased impact forces at higher level of competition. The use of headgear (i.e., scrum caps), although beneficial in preventing contusions and lacerations, has not been shown to clearly decrease the incidence of mild traumatic brain injury.