In a previous blog we looked at the occurrence of injuries in swimmers, particularly of the shoulder. Today I wanted to look at another area of the body, the knee, which still records a high number of incidences within elite and amateur swimmers. Breaststroke is the most common competitive stroke in which elite athletes report experiencing knee pain. It can be difficult to quantify the true number of knee injuries associated with swimming as there is a poor correlation between symptoms and structural abnormalities of the knee. Many swimmers will actually present with abnormalities of the knee, even without symptoms and vice versa, which can develop over many years. In fact knee abnormalities were shown to be around 69% more frequent in swimmers on MRI compared to non-swimmers. The most common abnormalities were infrapatellar and prefemoral fat pad oedema, bone marrow oedema and joint effusion. As stated, these do not necessarily match up with symptoms and as such, assessment and treatment should be individually based.
Similar to other injuries in swimmers, injuries to the knee occur predominantly from overuse due to the pressure of water and stress on the muscles, tendons and ligaments in the area, particularly around the front and inside of the knee.
Breaststroker’s have a 5 times higher risk of developing knee pain compared to that of other strokes due to the nature of the “frog” kick. Anterior knee pain can also be present with other strokes due to the force required during a push off the wall and with the “flutter” kick used, such as with freestyle. Risk factors can be both intrinsic and extrinsic meaning they can be due to the body themselves such as muscle abnormalities as well as external factors such as training load and poor recovery.
Identifying risk factors of overtraining, poor biomechanics or technique and early signs of injury are important to minimise time off due to pain at the knee. Trying to minimise the amount of hip abduction as well as hip and knee flexion and external rotation can offload the amount of stress through the knee during the whip action of the breaststroke kick. Strength, endurance and flexibility of the glutes, adductors, hip flexors and quadriceps through land based exercises can help minimise the forces experienced through the knee and assist with minimising the risk of injury. Rest and gradual return to sport, in combination with these exercises, are essential for rehabilitation and decreasing the risk of reinjury in the future.
Reference: Wanivenhaus, F., Fox, A., Chaudhury, S. and Rodeo, S., 2012. Epidemiology of Injuries and Prevention Strategies in Competitive Swimmers. Sports Health: A Multidisciplinary Approach, 4(3), pp.246-251.