43 Thames Street, St Albans, Christchurch 8013 Phone: (03) 356 1353. Website: philip-bayliss.com Hamstring Strain The hamstring muscles are very susceptible to tears, strains and other common sporting injuries. Those athletes particularly vulnerable are competitors involved in sports which require a high degree of speed, power and agility. Sports such as Track & Field (especially the sprinting events) and other sports such as soccer, basketball, tennis and football seem to have more than their fair share of hamstring injuries. Hamstring Anatomy The hamstring group of muscles, located at the back of the upper leg, are actually a group of three separate muscles. The top of these muscles are attached to the lower part of the pelvis, and the bottom of the hamstring muscles are attached to the lower leg bone just below the knee joint. The technical or anatomical names for the three hamstring muscles are semimembranosus, semitendinosus and biceps femoris. The shows the muscles located at the rear of the upper right leg. The three specific hamstring muscles can be seen on the picture, by looking for the
anatomical names located half way down the right hand side. How is the Hamstring Strained? During sprinting the hamstring muscles work extremely hard to decelerate the tibia (shin bone) as it swings out. It is in this phase just before the foot strikes the ground that the hamstrings, become injured as the muscles are maximally activated and are approaching their maximum length. A pulled hamstring rarely manifests as a result of contact -if you have taken an impact to the back of the leg it should be treated as a contusion until found to be otherwise. Preventing a Pulled Hamstring: One of the most important methods of preventing a pulled hamstring is to warm up correctly- this has been scientifically proven to reduce the risk of hamstring strain. This should consist of some light aerobic exercise followed by stretching and sports specific drills with gradually increasing intensity. Other factors which increase the likelihood of suffering a hamstring strain include: Age: The older the individual the greater at risk to a pulled hamstring. Previous Injury: Prior injuries to the hamstrings or adductor muscles can greatly increase the chance of future injury. Flexibility: Research suggests that the greater the flexibility of the hamstrings the less prone they are to injury. Hamstring strength: Similarly studies have shown that lack of hamstring strength is strongly linked to hamstring injury. Lumbosacral nerve impingement: Nerve impingement in L5-S1 can lead to associated hamstring muscle weakness. Tiredness and fitness: When a player is fatigued he/she loses coordination between certain muscle groups. The biceps femoris muscle is known to become damaged due its two portions being innervated by two separate nerves. In states of tiredness, lack of synchronization between these two nerves can lead to a mismatch in firing resulting in a pulled hamstring. A hamstring injury or strain is an injury that results from a pulling action, which stretches or tears the muscles and/or tendons. (The term sprain refers to an injury of the ligaments, as opposed to a strain, which refers to an injury of the muscle or tendon.) Remember; ligaments attach bone to bone, were as tendons attach muscle to bone.
Injuries to the muscles and tendons of the hamstrings are usually graded into three categories, and these injuries are referred to as: first; second; or third degree strains. Severity of a Pulled Hamstring: Strains are graded 1, 2 or 3 depending on severity. Grade 1 consists of minor tears within the muscle. A grade 2 is a partial tear in the muscle and grade 3 is a severe or complete rupture of the muscle. Grade 1: What does it feel like? May have tightness in the posterior thigh. Probably able to walk normally however will be aware of some discomfort Minimal swelling. Lying on front and trying to bend the knee against resistance probably won't produce much pain. Grade 2: What does it feel like? Gait will be affected-limp may be present. May be associated with occasional sudden twinges of pain during activity. May notice swelling. Pressure increases pain. Flexing the knee against resistance causes pain. Might be unable to fully straighten the knee. Grade 3: What does it feel like? Walking severely affected- may need walking aids such as crutches Severe pain- particularly during activity such as knee flexion. Noticeable swelling visible immediately.
Exercises Static stretching Internal rotation Sit with one leg bent and the other straight out in front. Rotate the straight leg inwards and lean forward at the hips to feel a stretch under the thigh. Hold stretch for 30 seconds. Repeat the stretch throughout the day at least 5 times. External rotation Sit with one leg bent and the other straight out in front. Rotate the straight leg outwards and lean forward at the hips to feel a stretch under the thigh (image 2). Hold stretch for 30 seconds. Repeat the stretch throughout the day at least 5 times. Contract - Relax (PNF) Stretching These are stretching techniques involving the stretch reflex. They place more strain on the muscles so should not be used within the early stages (first few days) of rehabilitation. The method is as follows: A short warm-up should be performed before using this type of stretch. The athlete lies on their back and gets a partner or therapist to raise the straightened leg as high as is comfortable.
Contract - The athlete pushes down against resistance from their partner at 20% of maximum effort. The resistance must be great enough so that the leg cannot move. This contraction is held for 10 seconds The athlete then relaxes and allows their partner to lift the leg higher until they feel a stretch again. Repeat the process until no more gains are possible. Dynamic Stretching This involves gentle swings of the leg forwards and backwards gradually getting higher and higher each time. Around 10 to 15 swings on each leg should be enough. The stretches can be done early in the morning (be careful not to force it) as this will set the length of muscle spindle for the rest of the day. Do not attempt this type of stretching in the early stages of rehabilitation, or if it is painful. It works by using the properties of muscle spindles. A muscle spindle is a sensor in a muscle that senses amount of stretch and speed of stretch. By gradually taking the leg higher and higher the muscle spindle allows it to go safely and lengthen the muscle. If the muscle is forced then a stretch reflex is initiated which causes a reflex contraction (shortening) of the muscle. This is called ballistic stretching and can damage muscles. Dynamic stretching is particularly important when returning back to full fitness, especially when speed work is involved. Muscles need to be able to move throughout their full range of motion at speed - not just when stationary.