Football is one of the most popular sports worldwide and requires the player to have considerable stamina while superimposing sprinting, jumping, tackling, rapid changes of direction and kicking. This contact sport has a significant risk for acute and overuse injuries.

The term football injury encompasses all injuries that occur during participation which vary in terms of their anatomical location and severity. Therefore, the overall injury value does not provide enough detail into which injuries are the most common and as such isn’t particularly useful, when trying to lower the occurrence of injury. Instead, it is more valuable to identify the specific, most problematic injuries which are the largest contributor towards the high rate of injury found in football. As such, it may be possible to apply suitable interventions to lower the risk of these specific injuries [35, 36].

Due to the bipedal nature of football, many injuries occur to the lower extremity. Across this region, the ankle and knee joints are most commonly injured, with muscle and tendon strains and ligament sprains being consistently reported. However, although these sites are most common, the risk of injury to these regions can vary throughout the year [30, 32].

In sports such as football that start in summer and early autumn, the risk of injury can increase during this time. Woods et al. observed the presence of an early season bias towards certain injuries, which is not typically reported in summer football competition or indoor sports such as basketball. These injuries are generally less severe than those experienced at other times, with a significantly greater percentage of slight and minor injuries being observed. However, it has been shown that the experience of an initial injury will put the participant at a considerably greater risk of reinjury at a later date. Indeed, one third of football players who experience a minor injury in the first instance, sustaining a more serious injury at the same location. Likewise, in response to the first injury, participants may change their movement patterns. This can put other previously less used structures at an increased load and unexpected stress, accentuating the risk of a new injury to result. Therefore, much of the high injury rate observed in football may be reduced by establishing the causes of the most common injuries during the preseason period [53].

The biomechanical studies that evaluate the pelvis movement in football were poor. The pelvis contains the centre of gravity of the body and acts as the fulcrum for all athletic movement in football. Anatomically and functionally, this area is extremely complex with several mobile and fixed articulations associated with powerful muscle groups, aponeuroses and ligaments that make it difficult to calculate accurately forces and associated moments [54].

The hip joint is the main area of the pelvis that has been formally evaluated biomechanically with in vivo prosthesis monitoring. The hip effectively acts as a multiaxial ball-and-socket joint upon which the upper body is balanced during stance and gait. Stability of this joint is critical to allow motion while supporting the forces encountered during activity. Nearly all motion between the femoral head and acetabulum is rotational, with no detectable translation because of the congruency of the articulating surfaces. The high degree of articular congruency is provided by the bony architecture of the joint and the acetabular labrum, articular cartilage, joint capsule and surrounding musculature [1, 6, 16, 38, 43, 47].

The joint reactive forces calculated through the hip joint are five times the body weight while jogging and over eight times the body weight during athletic activity or stumbling. These forces are further increased in single stance, which commonly occurs in football with kicking, jumping or cutting-in.

The labrum is a complex structure consisting of a fibrocartilaginous rim composed of circumferential collagen fibres spanning the entirety of the acetabulum and becoming contiguous with the transverse acetabular ligament. The complete physiologic function of the labrum is not entirely defined, but it appears to serve multiple purposes including a limitation of extreme range of motion and deepening the acetabulum to enhance the stability of the hip joint. The labrum contributes approximately 22% of the articulating surface of the hip and increases the volume of the acetabulum by 33%. In athletic motion, the labrum undergoes shearing forces while limiting femoral head motion, which can result in acute labral tears or chronic degeneration. Indeed, in retired football players, there is a high incidence of premature hip osteoarthritis, and there is now an increasing recognition of osteochondral and labral injuries occurring during active playing careers [6].

In football, considerable reactive forces also act through the anterior pelvis, in particular the symphysis pubis, inguinofemoral aponeuroses and parasymphyseal muscles. The symphysis pubis and rami function as an effective strut modulating reactive forces between the lower limbs and axial skeleton. Biomechanical studies have attempted to reproduce running and single stance forces in fresh cadaver pelvis and measured forces of the order of 300 N across the symphysis with normal relative pubic body movement of up to 2 mm in the vertical plane. The pelvis is normally tilted anteriorly in relation to the hip and lower limb, and this relationship must be maintained through all the complex athletic movements that occur in football. This core stability is thought to be crucial for normal and repetitive athletic activity of the pelvis, which in turn acts as the stabilizer for effective athletic function of the lower limb kinetic chain. Studies have shown that preseason weakness of the hip abductors and external rotators predisposes to lower limb injury and decreased adductor function predisposes to further ipsilateral adductor injury [1, 16].

In football players, a prospective study of the elite teams in UEFA during seven seasons found a total of 628 hip/groin injuries accounting for 12–16% of all injuries per season. Acute groin injuries in football include myotendinous strain of adductor longus or abdominal muscles, but have a good response to rehabilitation. Chronic injury and pain in this region may be career ending as it can be extremely difficult to diagnose and treat effectively. The increased incidence of chronic injury in sports that require constant cutting-in may relate to chronic shearing forces being further exacerbated, if the player develops one dominant leg and is commonly in single stance. Groin injury has been described more frequently in football players and is a significant problem estimated to constitute 10% of acute and 18% of chronic football-related injuries [12, 16, 17, 54].

Knee injuries are prevalent among a variety of competitive sports, especially those that involve sprinting, jumping and landing both with and without passing a ball, cutting-in and direct impact. The incidence of knee injuries during competition is 15–19% of all injuries. Of these, 35–37% are strains, 20–21% sprains and 16–24% contusions. However, knee injuries account for 58% of all major injuries. Two of the most common sports-related knee injuries are patellofemoral pain syndrome (PFPS) and anterior cruciate ligament (ACL) injuries [14, 31].

The three main factors that contribute to an increased risk of knee injury in football are the age of the player, a previous injury and the ligamentous status of the knee. Females sustain more injuries during training than males, whereas males sustain more injuries during competition, and particularly during competition in contact situations, with the tackled player being the more susceptible to injury. The playing environment has a role, with a higher number of injuries in indoor football, of which the majority are non-contact. It is not surprising that foul play was identified as a risk for a major knee injury, with 20% of illegal activity-related knee injuries requiring surgery [15, 43].

The high incidence of major knee injuries in female players is of great concern. The majority are non-contact injuries that occur with a change in direction. Many aetiological factors have been considered and include anatomical and structural differences between men and women, muscle strength and neuromuscular activation patterns as well as hormonal influences on knee stability. Although there has been little reported gender-related difference in injury patterns elsewhere in the body, there seems to be a significant increase in the incidence of non-contact internal derangement of the knee in female football players relative to male counterparts [2].

The different biomechanics of muscle and joint recruitment in running and especially landing after jumping have been studied in female football players and matched male controls. When an athlete lands on one leg after jumping, considerable translational force is produced across the knee joint. This is increased in sports where the athlete wants to push off immediately in another direction, requiring forceful thigh muscular contraction resulting in further femur rotation and ligament stress. Muscular recruitment can significantly modify the degree of knee flexion and stress directed across the joint, with the hamstrings in particular acting to decrease tibial anterior translation. Concomitant injury or fatigue of these muscles can precipitate a serious knee injury on landing as more force is transmitted through the knee ligaments alone.