There is very little debate on the relevance of thigh muscle injury (both front and back) in elite track and field athletes specially for high-speed running and jumping. Their incidence, impact on athlete’s career and tendency to recur make them daily challenge for management. This applies specially to injuries involving the hamstrings and quadriceps, which are the most frequently injured muscle groups. Hamstring muscle injury (HMI) is one of the most prevalent injuries, especially in disciplines requiring high running velocities, with about 20% of athletes sustaining HMI per season. Male sex, older age, and disciplines requiring faster velocity have been reported to be associated with higher HMI risk while rectus femoris (RF) injuries are common in sports requiring maximal acceleration and sprinting. In a multi-sport American collegiate study, female track and field (T&F) athletes had the 3rd highest overall quadriceps injury rates next to male and female soccer players. In elite track and field athletes, thigh muscle injury is consistently recorded as the principal injury type and quadriceps injuries account for up to 25% of those injuries.

While sprinting, athletes commence from 4-point stance in blocks and gradually undergo transition to upright running. Consequently this acceleration phase varies with each and every step. During the running cycle, forces working across the RF are multiple and complex. Large forces are absorbed during the ground contact phase while force generation is necessary during midstance. In late stance, a large eccentric action acts upon the RF to initiate swing. During the swing phase a transition from eccentric to concentric action is supposed to be particularly vulnerable position for RF.  HMI can occur when undertaking a variety of functional activities. The most common mechanism of injury involves sprinting, either during the acceleration or the maximal velocity phases. Sprinting is a challenging task for the hamstrings from both biomechanical and neuromuscular perspective. The muscle–tendon unit (MTU) for the biarticular hamstrings undergoes an active stretch–shortening cycle during the late swing and stance phases of the sprinting stride cycle. Overall, the hamstrings must contract rapidly and forcefully on a repetitive basis during sprinting, and it is believed that such loading conditions may potentially make the hamstrings (specially the biceps femoris long head (BFLH) susceptible to injury.

The management of thigh muscle injury includes an accurate structural diagnosis and classification, training movement pattern of all individual muscles, prescribing strength exercise including eccentric training and applying multivariate models targeting contributing factors. Return to sports is primarily based on the clinical examination of range of motion, strength, palpation pain, alongside the successful progression of running without exacerbation. Prevention strategy should be multifactorial and multimodal including physical conditioning of athletes for improvement of sensorimotor control, technical movement modification, training load monitoring, lifestyle changes as well as psychological follow up.