The hamstring muscle complex consists of 3 muscle groups that include the Semimembranosus, Semitendinosus and Biceps femoris muscles.
Acute muscle injury can occur in any of these three muscles.
Hamstring strains are usually sprint-related or stretch-related
Hamstring strains are classified from grade 1-3, with grade 3 being the most severe.
Sudden, sharp pain at the back of the thigh occurring during sprinting or while performing a fast stretching movement.
Applying ice to injured area
Hamstring strengthening ranges from initial ROM (range of motion) exercises to resistance training.
Both stretching and strengthening exercises are key.
After the initial acute stage, very gentle static stretching exercises can begin as long as one is pain-free.
As your injury heals, dynamic stretching involving movement is introduced and eventually progressing to sports-specific and plyometric drills.
Example of Hamstring resistance training using weights. Other resistance modalities include resistance band training.