Relationship between foot posture and single leg power in young healthy recreational athletes: A cross-sectional study

Recreational athletes are individuals who achieve the World Health Organization (WHO) physical activity standards while participating in a variety of sports without a specific commitment or focus on competition, they are more susceptible to injuries of the lower extremity particularly those of the foot as they lack systematic training in the sport.

The foot is a complex structure with multiple articulations are important in the static and dynamic activities of an individual.Alterations in the foot posture results in malalignment of the knee, which can alter the length-tension relationship with the surrounding musculature, due to the closed kinetic chain effect. This affects the thresholds of the afferent receptors and hence affect the efferent responses which inhibit the muscle kinetic responses of the knee musculature, thus reducing single leg power as measured by hop tests.

Hop tests are performance-based tests that challenge the neuromuscular control, power generation, speed, acceleration, deceleration and agility with contribution from hip, knee and ankle. They are routinely used as a tool to measure single leg power and thus often used as a return to sports criteria in athletes.

The relationship between ankle, knee and hip and their role within single leg horizontal jump performance has been documented by Kotsifaki et al, but there are a limited number of studies that link the foot contributions represented by the foot posture and intrinsic muscle strength, measured as the toe grip strength with single leg hop test and thereby single leg power.

 A study by Perez-Morcillo et al done on recreational runners suggesting that the foot posture is a good outcome used to predict running related injuries by classifying their feet based on the foot posture index scores.

With the direct effect of different types of foot posture on single leg power not currently known, this study could fill in the gap of knowing the effect of such foot posture types on single leg power. This could further benefit clinicians and athletes in designing tailor made protocols based on their foot posture for injury prevention, training and rehabilitation.