Hamstring Strain
What is it?
A hamstring strain is a common leg injury involving a tear in one or more hamstring muscles. A hamstring strain can range from mild to very severe, involving a complete calf muscle tear.
You have four hamstring muscles: Semimembranosus and Semitendinosus (medially) and Biceps Femoris – short and long heads (laterally).
Mechanism of Injury
Common reasons for a hamstring strain or injury can be primary or secondary.
Primary
The primary cause is a hamstring muscle timing issue. Essentially, intermuscular incoordination in the hamstring muscles during the switch phase. This switch phase occurs in late leg recovery and the initial swing phase.
Lack of “stiffness” and eccentric strength in the ham
string muscles during the ground contact phase of running. “Stiffness” refers to the ability of the hamstring muscle to absorb shock and rebound. Dropping a golf ball onto concrete is an example of stiffness. It immediately rebounds off the surface. Previous hamstring strain is an excellent indicator of the potential for future injury.
Secondary
Poor running mechanics. Usually, this is overstriding or poor pelvic control, which puts the hamstrings in a vulnerable position at ground contact.
Improper warm-up. Your warm-up must be active and dynamic to prepare the hamstring muscles for the forces involved.
Inappropriate training loads. Your hamstrings are primarily fast-twitch Type II fibres that fatigue quickly. It would be best to do high-speed work early in the workout to avoid fatigue, as close to warm-up as possible.
Fatigue (neural and local muscle).
Lower back pathology. Abnormalities of the lumbar spine or poor pelvic control cause nerve dysfunction, and subsequent muscle weakness can predispose you to injury.
Your playing surfaces. A wet slippery surface will put more strain on the hamstring due to slipping
Severity of Muscle Strains.
Muscle strains are graded as mild, moderate and severe. The more severe the strain, the longer the time to recover.
First Degree (Mild). This injury is the most common and usually the most minor. This injury is a ‘pulled muscle’ with a structural disruption of less than 5 percent. With a first-degree injury, you can expect to be back to sports within 1 to 3 weeks.
Second Degree (Moderate). This injury consists of a more significant, but still incomplete muscle tear. This a partial muscle tear and requires 3 to 6 weeks of rest and recovery before you can return to full activity.
Third Degree (Severe). This injury results in complete tearing of the muscle–tendon unit. A third-degree muscle strain can take many weeks or months to fully heal.
Common Management Techniques
While every hamstring injury and your sport’s demands differ, here are some general hamstring strain recovery times when you follow an optimal physiotherapist-guided rehabilitation program.
Grade 1 – 1 to 3 weeks
Grade 2 – 4 to 8 weeks
Grade 3 – 3 to 6 months. These may also require surgery.
Usually mild to moderate strains heal on their own with time, in the initial phase it is best to rest and avoid any aggravating activities. Crutches may be useful to decrease the amount of weight placed through the leg if walking is painful. Over the counter analgesia and anti-inflammatories can be used for pain relief, if these are not adequate or are being required long term then it is best to seek advice from a medical professional.
At home treatments can include ice, compression and elevation to limit swelling. Although it is difficult to keep a leg above the level of the heart (the optimal position for swelling reduction,) it’s a good idea to keep the leg elevated on the couch or on the bed potentially using extra pillows if needed.
Once the initial inflammation has resolved, focus can turn to strengthening and stretching
Prognosis
Most patients will recover completely if they follow the recommended treatment plan for Hamstring Strains. You can help prevent this condition by stretching before any physical activity and performing regular exercises to strengthen and stretch the muscles in the legs.