Hamstring Tightness Is Common Health And Social Care Essay

Hamstring Tightness Is Common Health And Social Care Essay Among the muscle undergoing adaptive shortening, hamstring is the one commonly going for adaptive shortening. The hamstring comprises of three large muscles namely semimembranosus, semitendinosus, and bicep femoris which arises from the tuberosity of ischium. They are present over the posterior compartment of the thigh and span the hip and knee joints. Hence they are the extensors of the hip and flexors of the knee. Hamstring tightness is common in normal individual because of immobilization of a tissue in a shortened position results in adaptive shortening. As the muscle shortens, its elasticity of the normal tissue was decreased and a change in the length tension relationship of the muscle, loss of flexibility also occurs. Hamstring tightness could make the musculo tendinous unit more susceptible to injury, increase resistance to various anatomical structures, which may lead to overuse syndrome. Tightness could also leads to pathological conditions at the joint on which the muscle acts, especially on a muscle like hamstring which passes over the two joints. Muscle tightness has a significant impact on neuromuscular control. Muscle tightness affects the normal length tension relationships. When one muscle in a force couple becomes tight or hypertonic, it alters the normal arthrokinematics of the involved joint. This affects the synergistic function of the entire kinetic chain, leading to abnormal stress, soft tissue dysfunction, neural compromise and vascular/lymphatic stasis. Muscle tightness also cause reciprocal inhibition. Increased muscle spindle activity in a specific muscle will cause decreased neural drive to that muscles functional antagonist. This alters the normal arthrokinematics of the involved segment. Flexibility has been defined as the ability of a muscle to lengthen and allow one joint (or more than one joint in a series) to move through a range of motion. Anderson and Burke defined Flexibility as the range of motion available in a joint or a group of joint that is influenced by muscles, ligaments and bones. Loss of flexibility means decreased ability of a muscle to deform. Loss of flexibility may lead to decrease in lumbar lordosis, reduction of muscle strength and quadriceps dysfunction during gait, lumbar pelvic rhythm was disturbed, anterior pelvic tilt was restricted, lumbar motion was increased. Excessive mobility of lumbar spine leads to overstretching of lumbar ligaments and consequently pain and instability. (Levangie and Norkin, 2001) Loss of flexibility can also cause pain arising from muscle, connective tissue or periosteum. (Hardy, 1989; Tillmann and Cummings, 1992) With regard to important role of hamstring flexibility restoration of its normal length is necessary. Muscle tissue length is thought to play an important role in efficiency and effectiveness of human movement. Benefits of flexibility is to enhance the range of motion, improved body position, potential relief of aches and pain, protection against low back pain and injuries, reduction of post exercise muscle soreness, and promotes relaxation. Hamstring tightness can be measured using the (1) Active unilateral straight leg raise test, (2) Passive unilateral straight leg raise test, (3) Sit and reach test, (4)Active knee extension test. Straight leg raise test are widely used as a neurologic tests, hence they do not give valid measures of hamstring tightness because of pelvic rotation that occurs during the test. Active knee extension test is the reliable test. Continuous ultrasound therapy increases tendon length by changing their viscosity and plasticity (Ziskin et al, 1986). Skeletal muscles have a higher rate of absorption of ultrasound waves when compared to fatty tissue. (Dyson, 1987; Low and Reed, 1990). Elevation of collagen tissue temperature affects on mechanical and physical characteristics of tissues and facilitates deformation of the collagen. As pain and discomfort was reduced during stretching and collagen fiber ability to tolerate greater forces was increased. Ultrasound increases soft tissue extensibility and may be an effective adjunct in the treatment of knee contractures secondary to connective tissue shortening (Folconer et al, 1992). Static stretching allow the muscle spindle to accommodate, reduces their firing rate; hence static stretch is effective in increasing the length of muscle. (Gordon and Ghez, 1991). Longer hold times during stretching of the hamstring muscles resulted in a greater rate of gains in range of motion (Feland et al, 2001). Stretch duration lower than 30 seconds did not increase muscle flexibility (Beaulien, 1981). Static stretch of 30 seconds is sufficient to increases the hamstring muscle length. Combination of ultrasound therapy with 30 seconds stretch is more effective than ultrasound therapy with 15 seconds stretch in increasing hamstring flexibility (A.Akbari, H.Moodi, A.A.Moein, and R.Nazok 2006). Muscle energy techniques (MET) are manually applied stretching techniques that use principles of neurophysiology to relax overactive muscle and stretch chronically shortened muscles. Muscle energy techniques (MET) have the ability to relax overactive muscles or stretch tight muscles and their associated fascial components when connective tissue or viscoelastic changes have occurred. When using Muscle energy techniques (MET), it is important to relax/inhibit the neuromuscular component before attempting to stretch the involved musculature. Two fundamental neurophysiologic principles account for the neuromuscular inhibition. The first principle of Muscle energy techniques (MET) is post contraction inhibition / autogenic inhibition / post isometric relaxation. The second principle is reciprocal inhibition. Muscle energy technique produced an immediate increase in passive knee extension in individuals with hamstring tightness (Ballantyne 2003). Muscle energy technique is significantly improving the hamstring flexibility in collegiate males (Wassim .M et al 2009). 1.1 NEED FOR THE STUDY: Continuous ultrasound therapy, static stretching, muscle energy technique (MET) are significant in improving hamstring flexibility in individuals with hamstring tightness. These methods of treatment are well accepted and practised by various researchers according to previous literature, but there was no study to compare the effect of muscle energy technique ( MET) and ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. So the purpose of this study is to analyse the efficacy of muscle energy technique and ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. 1.2 AIMS: To find out the effect of muscle energy technique versus ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. 1.3 OBJECTIVES: To study the effect of muscle energy technique in improving the hamstring flexibility in individuals with hamstring tightness. To study the effect of ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. To compare the effect of muscle energy technique and ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. 1.4 KEYWORDS: Hamstring flexibility, Muscle energy technique, Ultrasound therapy with static stretching, Active knee extension test. 1.5 HYPOTHESIS 1.5.1 NULL HYPOTHESIS: There is no significant effect of muscle energy technique in improving the hamstring flexibility in individuals with hamstring tightness. There is no significant effect of ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. There is no significant difference between the effect of muscle energy technique and ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. 1.5.2 ALTERNATE HYPOTHESIS There is a significant effect of muscle energy technique in improving the hamstring flexibility in individuals with hamstring tightness. There is a significant effect of ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. There is a significant difference between the effect of muscle energy technique and ultrasound therapy with static stretching in improving the hamstring flexibility in individuals with hamstring tightness. II.REVIEW OF LITERATURE HAMSTRING TIGHTNESS: Worrel et al (2003) Stated that hamstring injuries in athletes is mainly due to the lack of hamstring flexibility. Kishner and Colby et al (2002) Stated that adequate mobility of soft tissues and joints is thought to be an important factor in prevention of injury (or) reinjury to soft tissues. Donald E Hartig et al (1999) Stated that increase in hamstring flexibility decreases overuse injuries in lower extremities. Sarhmann.S et al (1997) Stated that muscle tightness and hypertonicity has a significant impact on the neuromuscular control. Muscle tightness affects the normal length tension relationship. Bullock-Saxton.J, Lewit.K et al (1997, 1984) Stated that muscle tightness alters the normal arthrokinematics of the involved joint. This affects the synergistic function leading to abnormal joint stress, soft tissue dysfunction, neural compromise and vascular or lymphatic stasis. Ronald F, Zernickle et al (1996) Stated that extracting flexibility changes related with structural and physiological changes influence the level of physical activity. Zachazewski et al (1989) Stated that loss of flexibility of hamstring may lead to decrease in lumbar lordosis, reduction of muscle strength and quadriceps dysfunction during gait. Cummings, GS, Crutchfeld, CA, Barnes et al (1983) Stated that tightness is referred to mild shortening of a healthy musculo tendinous unit otherwise referred to as a mild transient contracture. A muscle that is tight can be lengthened to all but the outer limits of its range. Normal individual who do not regularly participate in a flexibility program can develop mild myostatic contractures or tightness, particularly in two joint muscles such as hamstrings, rectus femoris or gastronemius. Fox E.L et al (1979) Stated that flexibility enhances movement by improving body awareness with greater ease and dexterity. Lawrence Gold et al Stated that the hamstrings are the muscles that run from behind and below the knees up to the back of the thigh till the sitbones. Soft tissue injuries, knee pain, torn menisci, chondromalacia patella and poor posture often come from tight hamstrings. Tight hamstrings can prevent the individual from reaching full extension or from bending over completely. ULTRASOUND THERAPY WITH STATIC STRETCHING Shadmer.A, Astaneh.H.N, et al (2010) Conducted a study to analyse the effect of two different modes (Continuous versus Pulsed) in decreasing the shortening of hamstrings. Thirty non impaired men aged 20 to 30 years were included. Ultrasound was applied over short hamstrings. Hamstring flexibility was measured by passive knee extension test. Continuous ultrasound of 2W/Cm ², 1MHZ, five minutes and Pulsed ultrasound of 200 µs burst of 1MHZ, 0.5W/Cm ², five minutes was used. They concluded that the heating effects of continuous ultrasound may be more effective than non thermal properties of pulsed ultrasound for increasing the flexibility of shortened hamstrings. Meroni, Roberto, Cerri, Cesare Giuseppe, Lanzarini, Carlo, Barindelli, Guido, Morte, Giancesare Della, Gessaga, Viviana, Cesana, Gian Carlo, DeVito, Giovanni et al (2010) Stated that the gain in flexibility was maintained for a period of 4 weeks after the cessation of training. This improvement was more significantly noticed in active stretching group by using active knee extension test than the passive stretching group. Buker N., Aslan E., Kitis A., Carluk U et al (2008) Stated that the superficial (or) deep heat applications before static stretching exercises shows positive effects to increasing flexibility of hamstring muscles. Nichole Lee Lounsberry et al (2008) Stated that the ultrasound treatment produced greater immediate gains in hamstring extensibility than moist heat packs treatment. A.Akbari, H.Moodi, A.A.Moein and R.Nazok et al (2006) Stated that the gains in range of passive knee extension obtained in continuous therapeutic ultrasound and 30 seconds stretch group were significantly greater than therapeutic ultrasound and 15 seconds stretch group in subjects with tight hamstrings. Denegar C, Saliba E, et al (2006) Stated that 3 MHZ ultrasound provides superficial heating, 1MHZ ultrasound heats tissue at depth of 3-5 cms and is considered to be a deep heating agent. Odunaiya N.A, Hamzat T.K, Ajayi O et al (2004) Stated that statically stretching tight hamstrings for any duration between 15 and 120 seconds on alternate days for six weeks would significantly increase its flexibility. The effect was also sustained for upto 7 days post intervention. Trae Sakiyo Tashiro et al (2003) Stated that the clinically practical parameters of thermal ultrasound in conjunction with static stretching is an effective way of increasing hamstring extensibility but ultrasound application location didnt showed difference in increasing knee extension range of motion in a healthy population. C.D.Weijer et al (2003) Stated that the static stretching is one of the safest and most commonly performed stretching methods used to measure muscle length. Feland et al (2001) Reported that longer hold times during stretching of the hamstring muscles resulted in a greater rate of gain in range of motion. Prentice WE, McClure M, Becker RO et al (2001) Stated that when slow stretch applied to muscle, golgi tendon organ get stimulated and thereby muscle tension is reduced. This leads is to an increase in length of muscle. Robert and Wilson et al (1999) Stated that static stretching increases muscle length by allowing muscle spindle to adapt overtime and cease fired. It also elicits golgi tendon response and therefore provides an effective flexibility training stimulus. William D Bandy et al (1996) Stated that a static stretch of 30 seconds at a frequency of single session is sufficient to increase the muscle length. Bandy WD, Irion JM et al (1995) Stated that the duration of 30 seconds of stretching is an effective time of enhancing the flexibility of the hamstring muscles. Bandy WD, Irion JM et al , Lentell G, Hetherington T et al, Madding SW et al (1994 ) Stated that Static stretching is a method of stretching in which the muscles and connective tissue being stretched are held in a stationary position at their greatest possible length for some period. When using static stretching on a clinical basis, stretches should be held a minimum of 15 to 30 seconds. Chan et al (1993) Stated that tendon reaches greater temperature and heat more quickly than muscle and the tendon was able to maintain vigorous heating for longer period than muscle. Draper D, Sunderland S, Kirkendall et al (1993) Stated that tendon tissue is less vascularized than muscle tissue; tendons will retain heat for longer periods of time. Folconer et al (1992) Stated that ultrasound increases soft tissue extensibility and may be an effective adjunct in the treatment of knee contractures secondary to connective tissue shortening. Gordon and Ghez et al (1991) Stated that static stretching may be effective in increasing the length of muscle due to the prolonged stretching which allows the muscle spindle to adapt over time and cease firing. Low and Reed et al (1990) , Dyson et al (1987) Stated that low absorption of ultrasound waves is seen in tissues that are in water content (eg.,fat), whereas absorption is higher in tissues rich in protein (e.g., skeletal muscle). Warren C, Lehman J, Koblanski J, Strickler T, Malone T, Masock A, Garrett W et al (1990) Stated that ultrasound therapy can be used to target the collagen rich tendinous unit of the hamstring muscle because of its ability to penetrate deeper tissues, and shown that increasing the temperature of collagen to 40 ° Celsius will increase the elasticity of the tissue. This increased extensibility allows for an even distribution of force and reduces the stress on localized areas of the tissue. Gajdosik RL , Godges JJ et al (1989) Stated that a low intensity maintained stretch that is applied gradually is less likely to facilitate the stretch reflex and increase tension in the muscle being lengthened. This is called static stretch. Ziskin et al (1986) Stated that an increasing in tendon length following continuous ultrasound therapy is due to change of their viscosity and plasticity. Beaulien et al (1981) Stated that stretch duration lower than 30 seconds didnt increase muscle flexibility. Coakley et al (1978) Stated that frequency of 1MHZ ultrasound used for patients with more subcutaneous fat who sustained injuries at deeper level because of its penetration to a depth of 3 to 5 cms. Lehman et al (1968) Emphasized on the thermal effects of continuous ultrasound compared to other heating modalities in increasing hamstring flexibility. De Vries HA et al (1962) Stated that static stretching offers advantages of using less overall force, decreasing the danger of exceeding the tissue extensibility limits, lower energy requirement, and a lower likelihood of muscle soreness. Static stretching also has less effect on the Ia and II spindle afferent fibres than ballistic stretching, which would tend to increase a muscles resistance to stretch and facilitate golgi tendon organ, thereby reducing the contractile elements resistance to deformation. MUSCLE ENERGY TECHNIQUE: Ahmad Faheem, Ahmad Shamin, Anjani Agarwal, Begum Shabana, Ram C.S, Waseem Mohd et al (2010) Conducted a study in Indian collegiate males on hamstring flexibility by comparing the effectiveness of muscle energy technique and eccentric training. Total of twenty males with hamstring tightness falling between age group of 18-25 years were included in the study. Hamstring tightness was measured by popliteal angle/active knee extension test. One group was treated with muscle energy technique and the other with eccentric training. This study stated that hamstring flexibility can be improved with muscle energy technique using post isometric relaxation than eccentric training. Wassim M et al (2009) Reported that muscle energy technique using post isometric relaxation significantly improving the hamstring flexibility (by active knee extension test) in normal Indian collegiate males with hamstring tightness. Azadeh Shadmehr, Mohmmed Reza Hadian, Sedigheh Sadet Naiemi, Shohreh Jalaie et al (2009) Concluded that the hamstring stretches in normal young women using either static stretch or muscle energy technique had similar effects on restoring flexibility to hamstrings. Madeline Smith, Gary Fryer et al (2008) Stated that the muscle energy technique is effective in increasing hamstring extensibility, and there appeared to be sustained improvement one week following the initial treatment. Ross A, Clark et al (2008) Stated that muscle energy technique can produces creep and plastic changes in the connective tissue thereby the length of the muscle can be increased. Lindsey Samilian et al (2007) Stated that muscle energy technique is a method used to strengthen weak muscles, lengthen the short muscles (or) increase a muscles range of motion. These techniques involve stretch during which a reciprocal force is imposed on the targeted muscle for short period of time, causing the muscle to relax and stretch further. Ballantyne F, Fryer G, MC.Laughlin P et al (2003) Conducted a study to find the effectiveness of muscle energy technique in increasing passive knee extension and to explore the mechanism behind any observed change. Forty asymptomatic subjects between age of 18 to 45 years were randomly allocated to experimental and control group. Experimental group was given with muscle energy technique and Control group with no treatment. They concluded that muscle energy technique produced an immediate increase in passive knee extension. This observed change is due to an increased tolerance to stretch. Chaitlow L, Liebenson C et al (2001) The other name for Muscle energy technique is active muscular relaxation technique. Freyer G et al (2000), Richard L, Gajodsik, Melonie A, Rieck and Debra K et al (1993) Stated that an increase in flexibility after muscle energy technique occurred due to biomechanical or neurophysiologic changes or due to an increase in tolerance to stretching. Lewit et al (1999) Concluded that post isometric relaxation is directed towards relaxation of hypertonic muscle, especially if this relates to reflex contraction or the involvement of myofascial trigger points. Lewit, Libenson, Murphy et al (1999) Stated that post isometric relaxation is an excellent technique for treating neuromuscular component muscle of a stiff, shortened or tight muscle. Lewit et al (1999), Greenman et al (1989) Suggested that in muscle energy technique, the holding time of 7-10 seconds is more effective than 3-5 seconds. Kuchera et al (1997) Stated that increase in range of motion of a joint after Muscle energy technique is based on neurological mechanism via inhibitory golgi tendon reflex. Muscle energy technique activates this reflex during isometric muscle contraction. Muscle energy technique produces a stretch on golgi tendon organ and a reflex relaxation of muscle. Goodridge and Kuchera et al (1997) Suggested that 3 repetitions of isometric contractions is optimal in applying muscle energy technique. Lederman et al (1997) Stated that a viscoelastic change in muscle is responsible for the increase in muscle flexibility after muscle energy technique. Chaitlow L et al (1997) Stated that the isometric contraction should be held for 10 seconds. This is the time required to stimulate the excitatory threshold of the golgi tendon organ, which has a neurophysiologic inhibitory effect on the muscle spindle. This provides the opportunity to take the muscle into a new range of motion. Following the isometric contraction, there is a latency period of approximately 25 to 30 seconds, during which the muscle can be stretched. Philip Greenman et al (1996) Stated that manual medicine treatment procedure includes Muscle energy technique which involves the contraction of the subjects muscle by the voluntary effort in a precisely controlled direction, at different levels of intensity, against a counterforce applied by the operator. This procedure can be used to lengthen a shortened, contracted or spastic muscle; to strengthen a physiologically weakened muscle; to reduce localized oedema, to mobilize an articulation with restricted mobility. Ward, Robert C et al (1990) Stated that muscle energy technique is an active, direct technique (engaging the barrier) that promotes muscle relaxation by activating the golgi tendon reflex. Libenson et al (1989) Stated that muscle energy technique is effective in treating the muscle tension disorder and it effectively relaxes stretches, strengthens the muscles and re-educate abnormal sensory motor pathway. Lewit et al (1986) Stated that when a muscle is isometrically contracted its antagonist will be inhibited and reduce tone immediately. Stiles and Greenman et al (1984) Suggested that muscles which requires stretching (agonist) should be the main source of energy for isometric contractions and achieves a more significant degrees of relaxation and so a more useful ability to subsequently stretch the muscle were the relaxation effect being achieved through use of antagonist (using reciprocal inhibition). ACTIVE KNEE EXTENSION TEST: C.M. Norris et al (2005) Stated that active knee extension test when used in conjunction with goniometry, accurate surface making, and manual monitoring of the test leg is a reliable measure of hamstring muscle length. M.Mathews et al (2005) Stated that active knee extension represents maximum length of hamstring muscles. Denise M. Cameron, Richard W. Bohannon et al (1985) Stated that active knee extension test is said to be a useful alternative to the straight leg raise test for providing an indication of hamstring muscle length. Gajdosik R.L et al (1983) Stated that active knee extension test is a more objective measure of hamstring tightness which produces high reliability co-efficient. III. METHODOLOGY 3.1 STUDY DESIGN: Pre test and post test experimental group study design. 3.2 STUDY SETTING: Study will be conducted at Physiotherapy Out Patient Department, KG College of Physiotherapy, Coimbatore. 3.3 STUDY DURATION: Total duration was one year. Individual received the treatment for the duration of one week. 3.4 POPULATION STUDIED: 30 normal individuals with hamstring tightness who fulfilled the predetermined inclusive and exclusive criteria were selected and divided into two experimental groups by simple random sampling method. Each group consists of 15 patients. Groups are named as group A and group B 3.5 CRITERIA FOR SELECTION 3.5.1 INCLUSIVE CRITERIA: Age between 18 to 25 years Both males and females Normal individuals with tight hamstrings (inability to achieve greater than 160 ° knee extension with hip at 90 ° flexion.) 3.5.2EXCLUSIVE CRITERIA: Low back pain Acute or chronic. Hamstring injury Acute or chronic. Soft tissue injuries around knee. Pregnancy. Metal implants in lower extremity. Recent fracture and stiffness in lower extremity. 3.6 VARIABLES: 3.6.1 INDEPENDENT VARIABLES: Muscle energy technique. Ultrasound therapy with Static stretching. 3.6.2 DEPENDENT VARIABLES: Hamstring flexibility. 3.7 PARAMETERS: Hamstring flexibility 3.8 MEASUREMENT TOOLS: Active knee extension test. Active knee extension test was used for measurement of hamstring tightness. The subject was instructed to lie on their back with hip and knees bent 90 degrees. Pelvic movement was controlled by the use of straps. By using the lateral condyle of femur as the goniometric axis, the stationary arm positioned along the femur, and the movable arm was positioned parallel to the leg. Keep hip and knee in 90 degrees then instruct the subject to straighten the knee as for as possible till a sensation of stretch being felt. Repeat the same for three times and mean were measured as the final result. 3.9 PROCEDURE: GROUP A: MUSCLE ENERGY TECHNIQUE. TECHNIQUE USED: Post isometric relaxation. INDIVIDUALS POSITION: Supine lying. PROCEDURE: Ask the individuals to assume supine position. Therapist flexes the affected hip fully and then extends the flexed knee with the back of lower leg resting on the shoulder of the therapist who stands facing the head of the table. Individual is asked to flex i.e. causing downward pressure against the therapist shoulder with the back of lower leg at the same time therapist resist the individuals voluntary effort so that, slight isometric contraction of hamstrings develops and individuals hold this for 10 seconds. After this effort, the individual is asked to exhale and relax the muscle completely. Then the therapist takes the muscle to its new restriction barrier without stretch. Starting from this new barrier, the same procedure is repeated two or three more times. FREQUENCY OF TREATMENT: Once in a day. TREATMENT DURATION: One week. GROUP B: ULTRASOUND THERAPY WITH STATIC STRETCHING: ULTRASOUND THERAPY: INDIVIDUALS POSITION: Prone lying PARAMETERS: FREQUENCY: 1 MHz INTENSITY: 2W/cm ² MODE: Continuous. AREA OF APPLICATION: Hamstring area DURATION: Five Minutes daily (Two minutes for medial hamstrings, Two minutes for lateral hamstrings and One min for between the two tendon). FREQUENCY OF TREATMENT: Once in a day TREATMENT DURATION: One week STATIC STRETCHING: TECHNIQUE USED: Active static stretching. INDIVIDUALS POSITION: Standing position. PROCEDURE: Subjects performed the hamstring stretch by standing erect with the foot planted on the floor and toes pointed forward. The heel of the foot to be stretched was placed on a plinth with the toes directed towards the ceiling. The subject then flexed forward at the hip, maintaining the spine in neutral position while reaching the arm forward. The subjects continued to flex the hip until a gentle stretch was felt in the posterior thigh. Then hold this position for 30 seconds and then relax for 10 seconds and repeat the same procedure for three more times a day. FREQUENCY OF TREATMENT: Once in a day. TREATMENT DURATION: One week 3.10 STATISTICAL TOOLS The following statistical tools used in this study is Paired t-test and Unpaired t-test Formula: Paired t-test = Where, = difference between the pre test versus post test = mean difference = total number of subjects = standard deviation Unpaired t-test was used to compare the mean difference between Group A and Group B. Formula: Unpaired t-test Where, = Mean of Group A = Mean of Group B Æ’Â ¥ = sum of the value n1 = number of subjects in Group A n1 = number of subjects in Group B S = standard deviation Level of significance: 5% IV.DATA ANALYSIS AND INTERPRETATION TABLE-1 PAIRED t TEST PRE TEST AND POST TEST VALUES OF GROUP A GROUP A MUSCLE ENERGY TECHNIQUE HAMSTRING FLEXIBILITY ACTIVE KNEE EXTENSION The comparative mean values, mean differences, standard deviation and Paired t test values of Group A , who were treated with Muscle energy Technique. S.NO GROUP A MEAN MEAN DEVIATION