Hamstring injuries are caused by overstretching or sudden sprinting, often with weak or tight muscles, poor warm-up, or fatigue.
Causes
- Sudden sprinting or kicking.
- Overstretching.
- Weak or tight hamstrings.
- Poor warm up.
- Muscle imbalance (strong quads).
- Fatigue.
- Previous injury.
Grades
Grade 1: mild strain. Grade 3: full tear.
Recovery
Grade 1: 1 to 3 weeks. Grade 3: 3 months or surgery.
Prevention
Warm up, strengthen hamstrings (Nordic curls) and stretch.
See a doctor
If you heard a pop or can’t walk.
Injury mechanics
The hamstrings are three muscles at the back of the thigh (biceps femoris, semitendinosus, semimembranosus). They are injured most often during sprinting, when they lengthen while contracting, or during overstretching. Hamstring strains are among the most common sports injuries and account for about 12 to 16 percent of injuries in soccer and track.
- Risk factors include previous hamstring injury, muscle fatigue, poor flexibility, strength imbalance with quadriceps, inadequate warm-up and age.
- Grade 1 is a mild strain with recovery in 1 to 3 weeks, grade 2 a partial tear needing 4 to 8 weeks, and grade 3 a complete tear requiring surgery in some cases and 3 to 6 months of recovery.
- Recurrence rates are around 12 to 33 percent.
Prevention and care
Nordic hamstring exercises have been shown to cut injury rates by about 50 percent in a 2019 meta-analysis. Warm up, build strength gradually and stretch. For treatment, use rest, ice, compression and gentle early movement. See a doctor for a pop, severe pain, bruising or inability to walk. Physical therapy guides return to sport.
Injury mechanics
Hamstring strains occur when the muscle is stretched while contracting, such as in sprinting. They account for about 12 to 16 percent of injuries in running sports. Risk factors include previous injury, poor flexibility, fatigue and muscle imbalance.
Prevention and care
Warm up, strengthen the hamstrings with Nordic curls, progress training gradually. Treatment: rest, ice, compression, then progressive loading. Severe tears may need surgery. Return after full strength is regained.
Anatomy and mechanisms
The hamstrings, made up of biceps femoris, semitendinosus and semimembranosus, span the hip and knee. Injury occurs in late swing phase of sprinting when the muscle lengthens under load. Hamstring strains make up 12 percent of injuries in elite football, with a high recurrence of about 12 to 30 percent.
Prevention evidence
Nordic hamstring exercise programs lowered injury rates by about 50 percent in a 2019 meta analysis. Sprint practice, hip strength and warm up reduce risk. For acute strains, avoid heavy stretching in the first days, then progressive loading. Return to sport when pain free and strength is within 90 percent of the other leg.
Based on data from the British Journal of Sports Medicine and the American Academy of Orthopaedic Surgeons
