Physiotherapist update: September 2019 Rina van der Merwe, Physiotherapist HAMSTRING STRAIN Definition: A hamstring strain involves a tear in on or more of the 4 hamstring muscles. It can be mild - Gr 1 (where you just feel a tightness), moderate – Gr 2 or severe – Gr 3 (when there is a complete tear). You have four hamstring muscles: semimembranosus and semitendinosus (medially) and biceps femoris - short and long heads (laterally). Causes: · Sudden onset, usually as a result of a quick motion that occurs with running. · Lack of ability of the hamstring to absorb shock and rebound and also lack of eccentric strength during the ground contact phase of running. Eccentric strength is the ability of a contracted muscle to slowly lengthen. · Poor running mechanics (overstriding or poor pelvic control) · Improper warm-up · Inappropriate training loads eg. doing high-speed workouts at the end of a long session (it should be done early – as close to warm-up as possible).<
