Hamstring injuries are one of the most common strains to affect athletes and the most common type of strain to affect the lower extremity. Hamstring strains can also be one of the most disabling injuries to the lower extremity. These strains are most common amongst athletes that participate in sports that involve a lot of acceleration, deceleration, kicking, jumping, cutting, and pivoting. - sports such as soccer, rugby, football, and raquet sports.
hamstring injuries occur
Factors that predispose an athlete to hamstring strains
Recurrence of hamstring strains
Where do hamstring strains occur
Physiology of injuries to the hamstrings
What does a hamstring injury look like
Classification of injuries
Treatment of hamstring problems
Is Dynamic or Static Stretching Better for Hamstrings?
Will Stretching Prevent Strains in Hamstrings?
How Does Dynamic Stretching Affect Previously Injured Athletes?
As with most muscle strains, the hamstrings are most commonly strained
during an eccentric contraction. Eccentric contractions involve the
lengthening of a contracting muscle. Hamstring strains are
usually caused by
a forceful hip flexion
while the hamstring is working to slow the extension of the knee as in
kicking or running.The
eccentrically during running to decelerate the forward movement of the
tibia. The hamstrings then change their role to
hip. It is at this point in running when the hamstrings go from
contracting eccentrically to concentrically that the hamstrings are
most vulnerable to injury.
What makes the hamstring particularly susceptible to injuries is the fact that the role of the hamstrings can change quickly many times during a task:
All of these performed rapidly and repeatedly results in
loading of the elongated hamstrings.
It is theorized that because the two heads of biceps femoris are innervated by two different nerves that there may be mistiming of contractions leading to a reduction in force produced with rapid eccentric contractions.
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It is thought that some of the following may predispose an individual
to a hamstring injury:
Hamstring injuries have almost double the rate of recurrence when
compared to other injuries in sports.(1,2,3,4) In football, studies
show 12% of
hamstring injuries will recur; whereas 7% is the recurrence rate of
other football injuries.
Animal research has shown that previous strains leaves the muscle more prone to injury. Recurring hamstring strains have definitely been a challenge in the clinic.
One reason for recurrence is the presence of scar tissue. Scar tissue does not possess the elastic properties of normal contractile and connective tissues of a healthy muscle. The scar does not stretch as easily and is therefore more susceptible to strain.
Another reason for recurrences is a failure to fully rehabilitate the injury. Disuse for even a short period can lead to weakness in other muscle groups and stiffness.
Although the most common period of reinjury is within a week of returning to sport, the risk remains for several weeks after healing has taken place. Players in my clinic are often anxious to return to their sport and I'm often forced to discourage them.
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The hamstrings make up the bulk of the muscle in the back of the thigh. They consist of the bicep femoris, semitendinosus, and semimembranosus. They function as extensors of the hip, flexors of the knee, and rotators of the tibia on the femur when the knee is flexed.
medial tibial condyle
pes anserine insertion
biceps femoris (long head)
head of fibula
biceps femoris (short head)
linea aspera near head of femur
head of fibula
common fibular nerve
The most common site of injury is at the musculotendinous junction of
the long head of the biceps femoris. The muscles of the body that cross
more than one joint are often those that are most susceptible to injury.
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As muscle fibres tear the body initiates an inflammatory response. Tears are often accompanied by bleeding as evidenced by ecchymoses present. The scar that the body uses to heal this tear is initially very weak, accounting for the high rate of recurrence and the fact that healing takes place over such a long period of time. Muscle physiology link.
People that experience a hamstring injury will say that it felt like
someone kicked them in the thigh. There is often a sudden
weakness and pain in the back of the thigh. There is swelling, pain
with resisted flexion of the knee, occasionally a defect in the muscle,
usually ecchymoses, and limited range of motion with a straight leg
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Grading of a hamstring injury is based on the degree of damage done to
Physical therapy for hamstring injuries is based on the muscles healing response. Studies have shown that a program that includes trunk stabilization exercises reduces the rate of reinjury. (5,6) The goal of rehabilitation is to restore function in the shortest time possible while facilitating healing to minimize the chance of recurrence.
Your goals of hamstring stretching
will determine what type of
stretching is best for you. If you are looking to increase flexibility
of your hamstrings because you need an increased range of motion for
activities such as yoga, running hurdles, as a hockey goalie, or for
dancing, then that appears best achieved through a program of static
stretching when you are not practicing.
Bandy et al (7) in a study published in the Journal of Orthopaedic ans Sports Physical Therapy looked at the effects of static stretching, dynamic stretching, and no stretching on hamstring flexibility.
58 people ranging in age from 21 to 41 performed the following stretching protocols over a course of six weeks:
A study by Pope et al
published in Medicine
in Sports and Exercise examined male army recruits to determine if static stretches reduce the risk of injury.(8) It was found that static stretches didn't result in a clinically meaningful reduction in the rate of injuries.
In this research the greatest predictor of injury was poor aerobic fitness. It is thought that static stretching will not reduce injuries for the following reasons:
According to a study
1999 (9) dynamic stretching prior to an explosive activity
the likelihood of having an injury.
E, Daneels L, Asselman. Muscle flexibility as a risk factor
for developing muscle injuries in male professional soccer players:
a prospective study. Am J Sports Med Jan 2003:31;1: p 41-6
2. Jonhagen S, Nemeth G, Eriksson E. hamstring injuries in sprinters: the role of concentric and eccentric hamstring muscle strength and flexibility. Am J Sports Med. March 1994:22:262-265
3. Orchard JW. Intrinsic and Extrinsic Risk Factors for muscle strains in Australian Football. Am J Spots Med, May 2001 :29;3 p300 Garrett W. Muscle Strain Injuries. Am J Sports Med, Nov 1996 v 24:6;p32
4. Woods C, Hawkins RD, Maltby S, Hulse M, Thomas A, Hodson A. The football association medical research programme: An audit of injuries in professional football – analysis of hamstring injuries. Br J Sports Med 2004;38:36-41.
5. Zuluaga M, Briggs C, Carlisle J, McDonald V, McMeeken J, Nickson W, et al. Sports Physiotherapy: Applied Science and Practice. 1st ed. Melbourne: Churchill Livingstone, 1995.
6. Sherry MA, Best TM. A comparison of 2 rehabilitation programs in the treatment of acute hamstring strains. J Orthop Sports Phys Ther 2004;34:116;25.
7. Bandy WD, Irion JM, Briggler M. The effect of static stretch and dynamic range of motion training on the flexibility of the hamstring muscles. J Orthop Sports Phys Ther. 1998;27:295–300
8. Pope, R. P., Herbert, R. D., Kirwan, J. D., & Graham, B. J. (2000) A randomized trial of pre-exercise stretching for prevention of lower-limb injury. Medicine and Science
in Sports and Exercise, 32, 271–277
9. Gesztesi, B. (1999). Stretching during exercise. Strength and Conditioning Journal, 21(6), 44.