A hamstring strain or a pulled hamstring as it is sometimes called is a tear in one or more of the hamstrings muscles. The hamstring muscle is a group of three large, powerful muscles (Semitendinosus, Semimembranosus and Biceps femoris) that span the back of the thigh, from the lower pelvis to the back of the shin bone. The hamstring is the important muscle that functions to extend the hip joint and flex the knee joint. Biceps femoris, in addition, has a second portion, known as the small head that originates from the lower outer portion of the femur bone itself.
NOTE:- The rear portion of adductor magnus is sometimes also considered as a hamstring muscle due to its alignment.
FUNCTIONS:- The hamstrings function predominantly in extending the hip and flexing the knee joints. Understanding how the hamstrings work gives vital clues as to their modes of injury. Acute, mild to severe hamstring strains are extremely common in many sporting activities, as well as normal daily activities. Sports that commonly cause a hamstring injury are sprinting sports that involve sudden accelerations. These include track and field, soccer, and basketball
MECHANISM OF INJURY:- During sprinting the hamstring muscles work extremely hard to decelerate the tibia as it swings out. Muscle strains and tears most commonly occur because of what is called an “eccentric contraction.” When this occurs, the muscle is trying to contract while another force (the ground, another player, etc.) is forcing the muscle in the opposite direction. This creates tremendous force on the muscle esp. biceps femoris muscle, becomes injured as the muscles are maximally activated and are approaching their maximum length and if the force is strong enough, it will tear the muscle fibers.
There are a number of factors that increase the risk of an individual to a pulled hamstring:
-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 risk of the hamstrings to future damage.
-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 a susceptibility to a pulled hamstring.
-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 within 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 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.
-A sudden sharp pain at the back of the leg during exercise-most probably during sprinting or high velocity movements
-Hamstring muscles going into spasm will be associated with pain on stretch and contraction.
-Swelling:-The accumulation of blood from the hamstring injury causes swelling of the thigh. This can make further muscle contraction difficult and painful. Wearing a compressive bandage can help control the swelling
-Bruising: – Small tears within the muscle cause bleeding and subsequent bruising. The bruise begins in the back of the thigh, and as time passes the bruise will pass down below the knee and often into the foot If the rupture is severe a gap in the muscle may be felt.
Severity of 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.
· 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
· 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.
· Walking severely affected- may need walking aids such as crutches
· Severe pain- particularly during activity such as knee flexion.
· Noticeable swelling visible immediately.
Treatment of a Pulled Hamstring:
What can the athlete do?
It is vitally important that treatment for a pulled hamstring starts immediately following injury. The most important phase for treatment is the first 48 hours post-injury. In this time the following can be carried out by the athlete themselves: Use R.I.C.E. (Rest, Ice, Compress, Elevate) technique
Use a compression bandage to minimize intra muscular bleeding.
Visit Physioline for early intervention:-Early mobilization of the injured lower limb is vital for the correct rehabilitation of the muscle. This includes stretching and strengthening exercises throughout the pain free range. These can aid with decreasing the swelling in the area. In addition, exercise will ensure that any new material will be laid down in correct orientation thus reducing the risk of subsequent injuries.
Physioline management-Sports massage techniques to speed up recovery- these are extremely important in the rehabilitation of the injury as massage breaks down the new collagen network allowing for correct fiber realignment and minimizing scar tissue.
In addition massage can increase the blood flow to the injured area-Electrical stimulation.
– Prescribe a rehabilitation program
–strengthening, stretching, sports specific training
– Advise on specific stretches
– Provide mobility aids such as crutches
Prevention of Pulled Hamstrings: -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 followed with some light aerobic exercise.
-A specific strengthening program for the hamstring muscle group is vital in those athletes regularly undertaking sprinting and high velocity sports.
-It is extremely important to continue to strengthen all other muscles in the region of the thighs, pelvis and lower back to ensure correct muscle balance
-Stretching both before and after exercise
-Regular deep tissue sports massage can help prevent muscle strains by identifying tight knots and weak points in the muscle.
-Thermal pants are thought to decrease the risk of injury.
VISIT PHYSIOLINE FOR FURTHER TREATMENT AND REHABILITATION