Hamstring Muscle Strains A Common Injury Physical Education Essay

Hamstring muscle strains are one of the common problems for many athletes which results in significant loss of on-field time. These injuries tend to heel slowly. Hamstring injuries are more common in sprinters and athletes, as they perform high-speed skilled movements. Once hamstring injury occurs, without proper rehabilitation and rest the athlete is at high risk for recurrence.

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Some pose complicated challenges remains after the injury rehabilitation, when returning the athletes quickly and safely to participate in sports. The most common soft tissue injuries in thigh occur in hamstrings; particularly at the musculo-tendinous junctions (Fox 1986, King and Robertson 1986). A 4 year study was conducted of injury rates for Memphis state university football team. The study showed that hamstring strains were the third most common injuries after knee and ankle injuries during sports.

The re-injury rate was 12% for hamstring strains when compared with an average re-injury rate of 7% for all other injuries. The injury recurrence is at highest risk during first 2 weeks of return to sports. Moreover, following return to sport nearly one third of these injury recurrences appear within the first year. An author, in his study reported that out of 30 sprinters 15 suffered from preceding hamstring strains.

The commonly utilized rehabilitation programs for hamstring injuries may be insufficient at resolving reduced tissue extensibility, possible muscular weakness and altered movement patterns associated with injury suggests the high re-injury rates. The primary objective of the rehabilitation program for hamstring is to restore the athlete with the level of activities previously carried out with minimal risk of recurrence of the injury of their participation in sports.


There are 3 hamstring muscles present in the posterior thigh: the semitendinosus, semimembranosus and biceps femoris. The semitendinosus originates at the ischial tuberosity and gets inserted at the pes anserine; the semimembranosus gets origin from the ischial tuberosity and inserts at the posterior medial tibia. The biceps femoris has two heads; a long head which originates at the ischial tuberosity and a short head originate at the postero-lateral femur. Both heads of biceps femoris gets inserted into the head of the fibula. The hamstring muscle acts as knee flexors and hip extensors.



A muscle is commonly strained or torn during rapid acceleration or deceleration movements. The most implicated cause of hamstring strains is the imbalance between the quadriceps and the hamstring muscles. The hamstring muscle group is a two joint muscle and thus the anatomical configuration of the muscle group is at increased risk and more susceptible for strains.

Clanton and Coupe (1998) describes about mechanism of injury. The underlying mechanism for hamstring strains is suggested to be the increased force generated during eccentric action of muscle as opposed to a concentric contraction suggested as. The most common 2 factors in hamstring injury are lack of adequate flexibility and strength imbalances in hamstring muscle group.

Eccentric contractions are characterized by active lengthening of muscle fibres. In eccentric contraction, as the speed of contraction increases the force of contraction also increases as well. Conversely, during concentric contractions shortening of muscle fibres occurs and inverse relationship between the speed and force of contraction. During late swing phase, the hip is flexed and the knee is extended which is suggested for injuries to occur. In a high speed running, the hamstring strain occurs during terminal swing phase of gait cycle. The greatest musculo-tendon stretch is incurred by the biceps femoris muscle, which is more often injured than the other two hamstring muscles (semimembranosus and semitendinosus) during high speed running.




Injuries to muscles and tendons of the hamstrings are generally classified into three categories. These injuries are mentioned as: the strains of first, second and third grade.

A first degree strain is less severe. It is the result of a minor stretch of the muscles and tendons, and is accompanied by a slight pain, stiffness and swelling. In general, very little loss of function is present after a first degree strain.

A second degree strain is the result of both stretching and some tearing of muscles and tendons. There is an increased pain and swelling accompanied with a strain in the second degree. A moderate loss of function of that exacting muscle will be present.

A third degree strain is the most rigorous of the three degrees of strains. Complete tear or rupture of one or more of the muscles and tendons is said to be third degree strain. It results in severe pain, massive swelling and gross instability.



While an athlete performing running or jumping activities in sport, hamstring injuries happens usually as a result of rapid acceleration or deceleration movements. There are some main modifiable risk factors which include:

* In-adequate warm-up leading to muscle fatigue

* Muscle tightness

* Imbalance of muscular strength with low hamstring to quadriceps ratio

* Previous injury.


In Grade 1 (Mild) : Local pain over posterior thigh, mild spasm, swelling, ecchymosis, local tenderness, mild pain on passive stretch and active contraction of the involved muscle, minor disability with loss of function and strength.

In Grade 2 (Moderate) : Local pain, moderate spasm, swelling, ecchymosis, local tenderness, moderate pain on passive stretch and active contraction of the involved muscle, moderate disability with impaired muscle function and strength.

In Grade 3 (Severe): Severe pain, severe spasm, swelling, ecchymosis, haematoma, tenderness, loss of muscle function, palpable defect may be present.


Stretching is believed to increase the range of motion around a joint through a decrease in visco-elasticity and an increase in compliance of muscle. By improving force absorption for a given length of muscle, thereby making the muscle is limited as the positive effect was demonstrated in only minor injuries.

Stretching exercises can be carried out as an individual training to enhance the flexibility of a muscle or as a warm-up planned to avoid injury and prepare the body for workout to pursue. Stretching gently lengthens the muscles before and after other exercises and helps to improve tissue elasticity and flexibility. It is suggested that a person should warm-up previous to stretching to enhance the blood flow. In turn this improved blood circulation makes the muscles more flexible. It is also not compulsory that all static stretches are supposed for 15 seconds at least prior to being released in order to stretch the muscle efficiently.


The development of muscle strength is an integral component of most rehabilitation or conditioning programs for individuals of all ages and all ability levels.

Strengthening of the hamstrings is an essential role in rehabilitation after injury to obtain the muscles back to their complete strength. This strengthening program will also facilitate to prevent anymore upcoming injuries. The most common adaptation to heavy resistance exercise is an increase in the maximum force-producing capacity of muscle, that is, an increase in muscle strength, primarily as the result of neural adaptations and an increase in muscle fibre size.


Agility training is a great way to help develop speed as well as becoming agile. This kind of method in training an athlete is enormously beneficial.

The benefits of agility training can certainly give a progression to any athletes in their overall performance. The skill to execute on the field and yet off the field is also improved. It also increases the running speed because running is the supreme foundation of all athletics. These agility exercises are also worn to increase the speed and quickness in all sports kind. These agility training vary from conventional speed training in that they integrate a lot more lateral movement.


Trunk stabilization exercises give strong, flexible trunk muscles that support well-aligned bones. It refers to progressive conditioning of the musculature of the pelvis and hip girdle, lumbar spine, abdominal region and peri-scapular musculature particularly as the use of these muscles relates to the performance of specific dynamic tasks involving the trunk of extremities. These exercises will strengthen the lower back and abdomen. Strengthening the core is essential to prevent all forms of injury around the lower back area. The concept of core stability has a theoretical basis in the treatment and prevention of various musculo-skeletal conditions. Many therapists now include a component of core stability training in the rehabilitation of a wide variety of lower limb injuries.

This had led some physical therapists to make use of a variety of trunk stabilization and progressive agility exercises for hamstring rehabilitation programs.

Muscle Strain:

A muscle strain is defined as an excessive stretch, which leads to muscle fibre damage and disrupts the integrity of related vascular and connective tissue structures.


Stretching is a form of physical exercise in which a specific skeletal muscle (or muscle group) is deliberately elongated to its fullest length in order to improve the muscle’s felt elasticity and reaffirm comfortable muscle tone.


Strength training is defined as a systematic procedure of a muscle or muscle group lifting, lowering or controlling heavy loads (resistance) for a relatively low number of repetitions or over a short period of time.


Agility is the ability to perform a series of explosive power movements in rapid succession in opposing directions.

Trunk Stabilization:

There is no formally endorsed definition of trunk stabilization. It refers to the balanced development of the deep and superficial muscles that stabilize, align and move the trunk of the body, especially the abdominals and muscles of the back.


The athlete returning to sport at previous level of functional performance with a minimal risk of injury recurrence is the primary goal of a rehabilitation program following a hamstring strain injury. The high re-injury rate may be due to the use of inappropriate criteria for determining suitability for return to sport or, alternatively, that traditional rehabilitation methods are insufficient for reducing risk for re-injury.

The need for the study was to determine that improved coordination of the lumbo-pelvic region allows the hamstrings for its optimal function at safe lengths and loads during athletic movement, thereby reducing injury risk.


The aim of this study is to compare the effectiveness of Stretching and Strengthening program with Progressive agility and trunk stabilization program in the rehabilitation of acute hamstring strains.


To compare the effectiveness of two rehabilitation programs for acute hamstring strains by evaluating the relationship between functional testing performances.

Null hypothesis:

There is no significant difference between the Stretching and Strengthening program against Progressive agility and trunk stabilization program in the functional testing performance of the athletes for acute hamstring strains on the day of return to sports.

Alternate hypothesis:

There is a significant difference between the Stretching and Strengthening program against Progressive agility and trunk stabilization program in the functional testing performance of the athletes for acute hamstring strains on the day of return to sports.


Bryan C. Heiderscheit, Marc A. Sherry, Amy Silder, Elizabeth and Darryl G. Thelen (2010) In a study says that there is a mounting evidence that the risk of re-injury can be minimized by utilizing rehabilitation strategies that incorporate neuromuscular control exercises and eccentric strength training, combined with objective measures to assess musculo-tendon recovery and readiness to return to sport.

Mason DL.Dickens V.Vaila(2007) In their study suggested that there is only limited evidence for rate of recovery can be increased with an increased daily frequency of hamstring stretching exercises. While managing a hamstring injury, the lumbar spine, sacroiliac and pelvic alignment along with the postural control mechanisms also must be concentrated. Lumbar stability and pelvic muscle control may also be a factor in reducing the rate of recurrence of hamstring injury.

G.Verrall, J.Slavotinek and P.Barnes(2005) Increasing the amount of anaerobic interval training, stretching whilst the muscle is fatigued and implementing sport specific training drills resulted in a significant reduction in the number and consequences of hamstring muscle strain injuries.

Thelen. D.G, E.S. Chumanov, M.A. Sherry and B.C. Heiderscheit(2006) In this article shows that hamstring strains are a common and recurrent injury among sprinting athletes and describes about the mechanics of hamstring injury and the influence of muscle co-ordination on hamstring mechanics. These observations are important for establishing effective injury prevention and rehabilitation programs.

Clanton TO, Coupe KJ (1998) Hamstring strains are among the most common injuries in athletes. This muscle injury occurs mostly at the myo-tendinous junction, when the force is concentrated. Concurrent pain-free stretching and strengthening exercises are essential to regain flexibility and to prevent further injury.

Gabbe BJ, Brason R and Bennell KL (2006) Evaluated the effectiveness of a pre-season eccentric training program on 220 players for preventing hamstring injuries. Five exercise sessions are completed over 2 weeks. Their finding suggests that a simple program of eccentric exercise could reduce the incidence of hamstring injuries.

David J.Magee, James E.Zachazewski, William S.Quillen (2009) Strain or overload of the hamstring tissues also may be due to a pelvic alignment fault or mal-alignment that changes the length/tension relationship of the hamstrings. Athletes with hamstring strain often show an anterior in-nominate tilt on the affected side. Rehabilitation of hamstring strains using progressive agility and trunk stabilisation exercises has been found to be more effective than a program emphasizing isolated hamstring stretching and strengthening and enable to return to activity more quickly than those treated with more conservative measures.

Robert Donatelli (2007) According to the clinical experience of the author, patello-femoral pain, hamstring strains, lateral hip pain results from lower quadrant core muscle deficits. Leerun et al demonstrated that core stability played an important role in injury prevention. Mascal et al reported that strengthening the hip, pelvis and trunk musculature resulted in a significant improvement in lower-extremity kinematics and ability to return to their sporting activities.

Thomas E.Hyde, Marianne S.Gengenbach (2007) Muckel states that hypomobility of the lower lumbar spinal segments is a cause of repetitive hamstring strains. Anterior pelvic tilt causing increased stretching of the hamstring also has been incriminated as a cause.

Peter Brukner and Karim khan (2007) Core stability program have shown the positive benefit in the management of sporting injuries. Many physiotherapists now incorporate an element of core stability program in rehabilitation of a wide variety of lower limb injuries and prevention of various musculoskeletal conditions.

Paul Gamble(2009) Single-leg hop tests of the type of vertical jump test have seen application in the rehabilitation setting to evaluate functional performance of injured and uninjured leg.

Agre JC (1985) Many of the recurrent injuries to the hamstring musculo-tendinous unit are the result of inadequate rehabilitation following the initial injury. The treatment for hamstring injuries should include training to maintain and improve strength, flexibility, endurance, co-ordination, and agility.

Hopper DM, Strauss GR, Boyle JJ, Bell J(2008) The functional hop performance in subjects with an ACL reconstruction and the hop tests results showed different levels of imposed demands on the knee that could be used to assess functional recovery and readiness to resume sport.

Andrea Reid, Trevor B Birmingham, Paul W Stratford, Robert Giffin (2006) conducted a study with 42 patients during rehabilitation after ACL reconstruction. The results show that the described series of hop tests provide a reliable and valid performance based outcome measures. These results sustain the utilization and facilitation in interpretation of hop tests for research and clinical practice.

JW Orchard, P Farhart, C Leopold (2004) suggests that the lumbar spine region pathology is a factor in some of the players who find that they have recurrent hamstring and calf musculo-tendinous injuries despite regular preventing maintenance. This brief report prompts us to consider lower lumbar pathology as a source of hamstring and calf problems (probably strains).

Croisier JL (2004) The risk factors which are examined in the literature have been associated with injury. Inadequate warm-up, invalid structure and the content of training, muscle tightness or weakness, agonist/antagonist imbalances, underestimation of an extensive injury and incomplete or aggressive rehabilitation are said to be most likely.

Malliaropoulos N, Papalexandris S, Papalada A, Papacostas E (2004) a total of 80 athletes with hamstring muscle strains were recruited in the study and the effects of stretching in rehabilitation of hamstring injuries were assessed. The results imply that stretching is of great value in treating muscle strain injuries in that it improves the effectiveness of the rest rehabilitation program.

Young W, Russell a, Burge P, Clarke a, Cormack S, Stewart G (2008), In a study determined the relationships between split times within sprint tests over 30m and 40m. They suggested that sprint tests over 30m and 40m can be conducted to provide information about independent speed qualities in athletes and concluded that this test can be used to estimate maximum speed capabilities.

Allen Hedrick, Lt. Jason Sanderson (1996) evaluated the effectiveness of training program using heavy resistance in improving vertical jump ability. Many strength and conditioning programs use the vertical jump test to measure the physiological adaptations from the training. Vertical jump testing is commonly used to measure improvements in the vertical jump for sports and as a general measure of lower body power in sports that requires high levels of lower body power.

Bill foran (2001) functional performance is a representation of actual efficiency through specific testing of gross performance (power, speed, etc). 40 yard dash speed represents the efficiency of the body. It allows the athlete to demonstrate the ability to store energy, efficiency, co-ordination and momentum management.


?? Stop watch

?? Measuring tape

Cone markers

Chalk or Ink

?? Thera-bands

Free weights


Ice packs

Stationary bike

?? Data collection sheet and recording sheet


An Experimental study design of a pre-test and post-test.

24 athletes with an acute hamstring strain were randomly assigned to 2 rehabilitation groups.

Group A – 12 athletes were assigned to the protocol consisting of static stretching, isolated progressive hamstring resistance exercise and icing (STST group).

Group B – 12 athletes were assigned to the program consisting of progressive agility and trunk stabilization exercise and icing (PATS group).


This study was carried out with the students in sports team of Sri Ramakrishna Matriculation School, Sri Ramakrishna Institute of Paramedical Sciences and SNR College, Coimbatore.


All acute hamstring strain patients were included in this study, hence this will be a simple random sampling.

Each group were assigned with 12 Athletes.

A sample of 24 Athletes were randomly selected and divided into Group A (STST group) and Group B (PATS group).

Both groups were evaluated after the rehabilitation programs for their functional testing profile by hop test for height and sprint test on the day of return to sports.


This study was carried out for the period of one year.


Group A

Phase I – 40 minutes each session, 2 sessions per day.

Phase II – 60 minutes each session, 2 sessions per day.

Group B

Phase I – 40 minutes each session, 2 sessions per day.

Phase II – 60 minutes each session, 2 sessions per day.


?¶ 14 – 22 yrs of age

?¶ Only males

?¶ Acute hamstring strains (within past 10 days)

?¶ Only first and second degree of injury


?¶ Less than 14 yrs or more than 22 yrs of age

?¶ Females

Non- acute hamstring injuries

Complete muscle disruption (Third degree injury)

Avulsion injuries

Recent other lower extremity injuries

Inguinal or femoral hernia


History of malignant disease

Incomplete healing

Rehabilitation of pelvis or lower extremity features

Nerve entrapment

Lack of daily compliance

Posterior thigh pain not consistent with hamstring

Any other impairment limiting participation in rehabilitation program.


a) Hop test for height (in centimetres).

b) Sprinting test (in seconds).

Group A:

Athletes received the protocol consisting of static stretching, isolated progressive hamstring resistance exercise and icing.

Group B:

Athletes received the program consisting of progressive agility and trunk stabilization exercise and icing.


In this experimental study, statistical method was used to show the effectiveness of functional testing profile in Group A and Group B was the dependent ‘t’ test.

The dependent ‘t’ test was calculated to find the difference between pre test and post test within the group, using the formula

Dependent ‘t’ test =


d = Difference of pre test and post test values.

N = Number of patients

Then the combined standard deviation is calculated using the formula

Combined standard deviation,

S =


X1 = Difference of post test values and pre test values of Group A

= Mean difference of Group A

X2 = Difference of post test values and pre test values of Group B

= Mean difference of Group B

n1 = Number of patients in Group A

n2 = Number of patients in Group B

With the combined standard deviation value ‘S’ obtained, and from the values of Group A and Group B, the independent ‘t’ test is performed to show the effectiveness. The obtained independent ‘t’ test values is compared with 22 degrees of freedom of two tailed table value. If the ‘t’ value is greater than table value of 22 degrees of freedom, we can reject the null hypothesis and accept the alternative hypothesis and show the effectiveness of the study.

Independent ‘t’ test was performed with the formula.

Independent ‘t’ test =


= Mean difference of Group A

= Mean difference of Group B

S = Combined standard deviation

n1 = Number of patients in Group A

n2 = Number of patients in Group B


The 4-phase program theorized that progressive stretching and strengthening of the injured tissue would help to remodel and align collagen fibres in the scar tissue. The acute phase (2-4 days) consisted of control of inflammation and early motion of the lower extremity in the sagittal plane. The sub acute period consisted of stationary biking, isolated hamstring progressive resistance exercises and pain-free stretching.

The re-modeling phase consisted of continued, isolated, hamstring progressive resistance exercises (PREs), with the addition of eccentric exercise and continued hamstring stretching. The functional phase included jogging, sprinting, sport-specific drills and continued hamstring strengthening and stretching.

Phase 1

Low to moderate


40 minutes


Treatment protocol

Stationary biking with no resistance – 10 mins.

Supine hip flexion with knee extension stretch – 4A-20 sec.

Standing hip flexion with knee extension stretch with slow side to side rotation during stretch – 4A-20 sec.

Contract-relax hamstring stretch in standing with foot on stool – 4A-10 sec contraction, 4A-20 sec stretch.

Sub-maximal isometric hamstring sets – 10 repetitions.

Icing in long sitting for 20 mins.

Progression criteria:

Athletes were progressed from exercises in phase 1 to exercise in phase 2 when they could walk with a normal gait pattern and do a high knee march in place without pain.

Phase 2

Moderate to high


60 minutes


Treatment protocol:

Stationary biking – 15 mins.

Moderate velocity walk – 5 mins.

Supine hip flexion with knee extension stretch – 4A-20 secs.

Standing hip flexion with knee extension stretch with slow side to side rotation – 4A-20 secs.

Prone leg curls with ankle weight for resistance – 3A-10 repetitions.

Hip extension in standing with knee straight using theraband resistance – 3A-10 repetitions.

Non – weight bearing foot catches – 3A-30 secs.

Icing for 20 mins (only if there is any local fatigue or discomfort).



Some other authors have described similar programs. As the pelvis is the origin attachment site for the hamstring muscles, it has been suggested that neuromuscular control of the lumbo-pelvic region, including anterior and posterior pelvic tilt, is needed to create optimal function of the hamstrings in sprinting and high-speed skilled movement. Changes in pelvic position could lead to changes in length tension relationships or force – velocity relationships.

This has led some clinicians to utilize various trunk stabilization and progressive agility exercises for hamstring rehabilitation programs.

Phase 1

Low to moderate


40 minutes

Treatment protocol

Side stepping – 3A-1 min.

Grapevine stepping in both directions – 3A-1 min.

Steps forward and backward over a tape line while moving sideways – 2A-1 min.

Single leg stand progressing from eyes open to eyes closed – 4A-20 secs.

Prone abdominal body bridge – 4A-20 secs.

Supine Extension Bridge – 4A-20 secs.



Side Bridge – 4A-20 secs on each side.

Icing in long sitting for 20 mins.

Progression criteria:

Athletes were progressed from exercises in phase 1 to exercise in phase 2 when they could walk with a normal gait pattern and do a high knee march in place without pain.

Phase 2

Moderate to high


60 minutes

Treatment protocol

Side stepping – 3A-1 min.

Grapevine stepping – 3A-1 min.

Steps forward and backward while moving sideways – 2A-1 min.

Single leg stand windmill touches of repetitive alternate hand touches – 4A-20 secs.

Push-up stabilization with trunk rotation – 2A-15 repetitions on each side.

Fast feet in place – 4A-20 secs.

Proprioceptive neuromuscular facilitation trunk pull-downs with theraband to the right and left – 2A-15 repetitions.




Icing for 20 mins (if any symptoms of local fatigue or discomfort are present).

Criteria for return to sport:

Subjects were allowed to return to sports when they demonstrated 5/5 strength when manually resisting knee flexion in prone with the hip in neutral extension, had no palpable tenderness along the posterior thigh and when they demonstrated subjective readiness after completing agility and running tests.


The calculations were tabulated for easier statistical calculations and better comprehension. The pre test and post test values of the functional testing profile are obtained by hop test for height and sprinting test were as follows:


The functional performance between pre-test and post-test of the individuals within the same group are calculated by using dependent ‘t’ test. For sprinting test, the mean difference obtained for group A is 2.27 and standard deviation is 0.471. Mean difference of group B is 2.65 and standard deviation is 0.393. In hop test for height, the pre and post test values are compared within the group and mean difference of group A is 13.6, where the standard deviation is 1.61. Mean difference of group B is 15.2 and its standard deviation is 1.94.

Performance on the functional testing profile was compared between the Stretching and strengthening program and progressive agility and trunk stabilization program and the t values are calculated using Independent ‘t’ test. In sprinting test, the calculated ‘t’ value is 2.18 with 22 degrees of freedom is greater than the table value, where p=0.05 respectively. In hop test for height, the ‘t’ value calculated is 2.16 with 22 degrees of freedom which is greater than the table value gives p=0.05. Hence, The p value is 0.05 in both sprinting test and hop test for height, it shows statistically significant difference between the two groups in their functional testing profile.


The purpose of this study is to show the effectiveness of STST group and PATS group for acute hamstring strains. In this study the rate of re-injury is hig