Anatomy Of The Hamstring
The hamstring muscles are located at the back of the thigh and consists of three separate muscles. The Biceps Femoris, Semimtendinosus and the Semimembranosus. Collectively these three muscles all work together to achieve hip extension and knee flexion, they originate at the ischial tuberosity, extending down the back of the thigh and along to either side of the knee.
The reasoning of a hamstring muscle strain is often unclear. In the late forward swing phase of running (just before your foot hits the ground) the hamstrings are at their greatest length and at this moment they generate maximum tension. During this late forward swing phase, the hamstrings contract eccentrically (muscle lengthening under tension), this slows down flexion of the hip and extension of the lower leg. At this point, a peak is reached in the activity of the muscle spindles in the hamstrings. A strong contraction of the hamstrings and relaxation of the quadriceps is required in this phase of running, if there is any miss coordination between theses opposing muscle groups, it can lead to a hamstring strain.
PREDISPOSING FACTORS/ RISK FACTORS of hamstring injuries
– Increased age
– Previous hamstring injury
– Limited flexibility
– Increased fatigue
– Poor core stability
– Strength imbalance
A hamstring strain results in a sudden sharp pain at the back of the thigh when it occurs during sporting activities, and can also be described as a “popping” or “tearing” sensation. A hamstring strain can result in muscle tightness and improved range of motion – knee extension and hip flexion. Visual presentation of swelling and bruising may be delayed for several days after the injury has occurred depending on the severity of the injury.
A hamstring strain does not always account for a complete tear of the muscle. A strain can be categorised into 3 groups according to their severity:
Grade 1 (mild): A few muscle fibres are damaged or ruptured. This rarely influences the muscle’s power and endurance.
Grade 2 (medium): Approximately half of the fibres are torn. Symptoms include acute pain, swelling and mild loss of function.
Grade 3 (severe): Ranging from more than half of the fibres ruptured to complete rupture of the muscle. It causes substantial swelling, pain and loss of function.
The main goal of physical therapy and rehabilitation is to restore the patients’ functions to the highest possible degree, and/ or return the patient to their sport to their previous level of performance and reduce the possibility of re-injury.
A study by Heierscheit, et al., (2010), portrayed that hamstring strain injuries remain a challenge for both athletes and clinicians, due to their high incidence rate, slow healing, and persistent symptoms. They also indicate that nearly one-third of these injuries recur within the first year following a return to sport.
During hamstring rehabilitation, there are a number of different types of therapies to utilise. But how effective are they and can they prevent a recurrence within the first year following a return to sport? Differential therapies include, eccentric exercises, dry needling. deep stripping massage, kinesiology tapping, ect.
In the studies reviewed, regarding differential techniques with treating hamstring strains, all have portrayed a positive effect towards the healing of a hamstring strain. However, many rehabilitation techniques work best when used in conjunction with other therapies, this allows for multiple positive effects towards restoring function and performance after a hamstring strain.
Here At Comfort Health
If you would like further advice on recovery after a hamstring injury, click here to book in with one of our team today. We can provide you with a tailor-made programme to help restore function and regain previous performance levels after a hamstring strain.
–Tyler TF, Schmitt BM, Nicholas SJ, McHugh M. Rehabilitation After Hamstring Strain Injury Emphasizing Eccentric Strengthening at Long Muscle Lengths: Results of Long Term Follow-up. J Sport Rehabil. 2016;24:1-33.
–Debowski SC, Westrick RB, Zylstra E, Johnson MR. Treatment of hamstring strain in a collegiate pole-vaulter integrating dry needling with an eccentric training program: a resident’s case report. Int J Sports Phys Ther 2013;8:328-339.