Risk of fatalities increase as a result of entrapments, either foot or full body on strainers [8], blunt head trauma and symptoms of hypothermia (disorientation, loss of consciousness) linked to sudden immersion in cold water. This can further cause hyperventilation, bronchospasm and even cardiac arrest [9]. As the formal cause of death is not always available, it is unclear whether drowning is primary or secondary to another injury. This is particularly the case when fatal injuries are reported in the media.

Fatal injuries are extremely rare with a rate of 0.16–0.27 per 100,000 participants per annum for WW rafters [10] and a rate of 2.1 per 100,000 white white-water kayakers [11]. For all white-water paddlers, an injury rate of 0.86 per 100,000 user days has been observed [11] which is similar to trekking [12].

Survey data has estimated that per 1000 paddler days, 4.5 injuries occur amongst recreational canoeist and kayakers [13] and 5.2 injuries amongst competitive slalom canoeists and kayakers [14]. When compared to other outdoor adventure sports, the incidence of injury is similar to alpine skiing but higher than cross-country skiing or windsurfing [15, 16]. The injury incidence in commercial white-water rafters which required medical attention was estimated as 26.3 per 100,000 participants [17]. A much lower injury incidence of 1.04–1.81 per 100,000 participants required hospitalisation [10]. As with most sports, the incidence of white-water injuries rises with increased exposure [13] and is much higher during competition than training (ten times higher in competitive slalom paddlers [14]).

White-water injuries and ill health can be categorised as acute trauma injuries, chronic overuse injuries and environmental injuries and ill health. Most research has involved self-report data, as opposed to clinical or medical diagnoses. What literature there is has identified the upper body as most susceptible to injury for canoeists and kayakers. This is unsurprising as it is a predominantly an upper body sport. White-water rafters, who are in close proximity with others and are more likely to fall in the river, when compared to canoeists and kayakers, have a different pattern of injury. The facial region (33 %) and lower limbs, specifically the knees (15 %), are more at risk than the shoulders (6 %) [17].

Survey data has suggested that 42–51 % of all canoe/kayak injuries require medical attention [13, 18]. The shoulder is the most common site for severe injury in canoe/kayak paddlers. One study reported 14 % of all injuries were shoulder dislocations [18]; another survey reported that 15 % of international-level elite paddlers had experienced at least one shoulder dislocation [14]. In addition, more than half of elite slalom paddlers have reported a history of shoulder injuries [19].

Injuries sustained by white-water paddlers occur:

In-boat injuries sustained by canoe/kayak paddlers tend to be in the upper body, as this is the most exposed and therefore vulnerable part of the body [8, 13, 14, 18]. Sudden internal or external forces on the body may overload a muscle group or joint resulting in muscle strain or joint sprain injuries, for example, forceful paddle strokes to make an eddy or an attempt to stay upright with a powerful support stroke. The shoulder and lower back are susceptible to strain/sprain injuries. Lacerations, contusions, abrasions and fractures to any exposed region of the body are common as a result of collisions with rocks [13]. This could be whilst upright or upside down prior to completing an Eskimo roll (a method of righting oneself following being upturned on a river) [8]. Collision injuries are the most common form of injury amongst rafters [17]. This is from colliding with other rafters (those in the middle of the raft are most at risk), especially if they are holding their paddle incorrectly, allowing the loose end to swing into others on the raft. Consequently, facial lacerations, contusions, abrasions and dental damage are common rafting injuries [17]. Lower extremity injuries can also occur whilst in boat. For example, rafters can entrap a foot in the gutter of the raft whilst being thrown out of their seat resulting in knee and ankle damage [8]. Paddling a kayak head-on into an obstacle causes a sudden deceleration that can sprain the ankles [8].

As previously mentioned, shoulder dislocations are not uncommon, e.g. 15 % of respondents of one survey had reported having at least one [14]. This is a severe injury, which typically requires several weeks of immobilisation and a prolonged absence from paddling. Strenuous high brace supports to avoid capsizing have been associated with the anterior displacement of the humeral head, resulting in either a dislocation or subluxation. Poor high brace technique is widely considered to make the shoulder vulnerable to dislocation (Fig. 23.4). A combination of shoulder abduction with external rotation and extension can lever the humeral head out of the glenoid fossa. Extension of the elbow also increases the force transmitted along the arm, increasing the risk of wrenching the humeral head out of the glenoid fossa. Good practice for a high brace involves reducing the abduction and external rotation of the shoulder, the elbow lower and further forwards than the shoulder, the hand in front of the elbow and the elbow flexed. It has been suggested that female paddlers, who generally have less muscle mass to help stabilise the shoulder, are at greater risk of shoulder dislocations [7]; however, there is little empirical evidence to support this claim.

Other extreme injuries may occur on grade V and grade VI descents and waterfall jumping. Although there are no scientific reports of these injuries, there are numerous anecdotal reports and online databases (e.g. American Whitewater) which provide some insight into such incidents. For kayak paddlers, descending waterfalls involves an inherent risk of spinal damage, including vertebral compression fractures, from the high-impact forces experienced on landing, especially if the boat lands flat [20]. Such injuries may cause paralysis. Other potential impact injuries include long bone and pelvic fractures, abdominal/chest trauma and head injuries. It is therefore important to have the relevant rescue and medical support teams available on site when attempting waterfall descents.

Turbulent water can cause craft to be unstable, resulting in a capsize and the paddler ‘falling out’ of their craft. In the event of swimming, it is important for the paddler to stay close to their craft as this provides an excellent flotation aid. In the event of ‘falling out’ of a raft, holding on to the perimeter rope whilst twisting and falling may cause contusions and abrasions on the hands, specifically around the fingers and fingernails. If the water is particularly powerful, holding on to the raft may be damaging as it puts a lot of pressure on the wrist, elbow and shoulder joints. In this situation, there is a risk of sprains.

Swimming in turbulent water is a highly unpredictable situation, where the swimmer has limited control and consequently there is a significant risk of impact with rocks and other obstacles. Frequent injuries to the lower extremities include lacerations, contusions, abrasions and fractures [10, 13, 17]. Although the lower extremities are at higher risk of injury, other regions of the body are also at risk [8]. It is recommended that swimmers adopt a defensive swimming position to avoid submerged obstacles. If defensive swimming is not adopted, the risk of entrapment will increase. Entrapments are rare but serious and tend to happen in shallower rivers (waist deep) or in flooded rivers where other obstacles become submerged (e.g. trees, fences) creating additional hazards. The most common form is a foot entrapment; this is where the foot or ankle is trapped by an obstacle such as a tree root or between two rocks. The force of the water can make it very difficult to dislodge the entrapped body part and a rescue may be required. Even minor entrapments typically causing abrasions and contusions with sprains and fractures are also possible. In extreme cases where the force of the water is great, drowning is a likely outcome. Entrapments are very serious and the victim needs to be rescued as quickly as possible from the situation. The severity of the accident will increase with time taken to rescue the individual.

Trekking to and from a river, portaging around rapids or performing a land-based rescue all increase the risk of ankle sprains, foot injuries and falls amongst paddlers. The uneven surface of a river bank is often slippery and unstable making these situations potentially hazardous, particularly when carrying a boat and/or other equipment. Robust footwear with good grip is highly recommended but not typically worn by paddlers.