Athletic Injuries 101: Hamstring Strain
Definition: A muscular strain is often known as a “pulled muscle” to many athletes and gym-goers. The hamstring is a group of three muscles, the biceps femoris, semitendinosis, and semimembranosis, all of which are very versatile muscles. They are long and slender, and are considered “2 joint” muscles, meaning they cross the hip and the knee. The job of the hamstring is to help extend the hip and flex the knee. They act alongside the quadricep muscles to stabilize the knee. These muscles are very vulnerable to injury.
Causes of Hamstring Injuries: The hamstrings are the most commonly strained muscles in the lower limb. The following reasons can contribute to such vulnerability of the hamstrings:
- Poor flexibility, poor muscular endurance, poor strength especially in comparison to the quadriceps, and poor coordination.
- Muscular imbalance of one leg over the other.
- Quadriceps to Hamstring Imbalance: The normal ratio of strength and flexibility should be 60:40 quadriceps:hamstring during slow muscle contraction and a 1:1 ratio during fast muscle contraction.
- Previous injury or inadequate rehabilitation
- Fatigue or over training (i.e. long/middle distance running)
- Inadequate warm up or improper/inconsistent stretching
- Ballistic activities such as sprinting, hurdles, kicking, stop& go, soccer, football
- Lumbar Facet Syndrome, L5S1 Intervertebral disc problems, sciatic nerve radiculopathies due to lower back injuries, chronic tightness in the piriformis/glute/hip musculature.
- Anatomical/structural leg length concerns:
- The longer leg will cause an increase in pronation at the foot, leading to increase rotation at the knee and an increase in hamstring stress/fatigue.
- The short leg will cause someone to over stride, therefore increasing knee extension and a greater hamstring stretch.
- Weak gluteal muscles, tight hip flexors or calves will decrease the demand on the hamstring.
Management:
- Ice: ice will help to vasoconstrict the blood vessels and therefore, help reduce any inflammation that is present.
- Compress: tape, a thigh sleeve, or compression shorts/pants will help to keep the lymphatic system draining inflammation from the area and increase circulation to the strained muscle fibers.
- Heat: apply a source of heat after 72 hours to allow a fresh blood supply to the area to increase healing. Heat should be alternated with ice to continue to keep swelling out of the area.
- Avoid aggressive manual therapy and stretching. Light stretching is okay, however avoid major stretching techniques to avoid straining the muscles even more.
- Rehabilitation exercises can begin within 72 hours to one week of injury.
Prognosis: Mild strains are usually pain free within two weeks of injury if take care of properly. Moderate muscle strains may take 4-6 weeks and recurrence is common.