Earticle

This study aimed to compare the short-term effects of sciatic nerve neural sliding and neural stretching exercises on hamstring muscle length and functional flexibility in wrestlers. The study participants in-cluded 74 wrestlers. The athletes were randomly divided into two groups: neural sliding and neural stretching groups. The hamstring flexibility and the functional flexibility were assessed using the active knee ex-tension limitation (AKEL) angle and the sit and reach (SR) test one day before and immediately after the neural mobilization exercises, respec-tively. A three-way repeated measures analysis of variance was con-ducted that examined the effect of mobilization type, time, and gender on interest in AKEL right leg, AKEL left leg, and SR test. There is not a significant difference between the effect of two different mobilizations on AKEL right and left leg, and SR test (P>0.05). It was determined there is statistically significant differences between premobilization and post-mobilization outcome measures for AKEL right leg (F=59.886, P=0.001), AKEL left leg (F=31.896, P=0.001), and SR test (F=22.630, P=0.001). There is not a statistically significant difference between males and females by these three measures neural sliding and neural stretching exercises to the sciatic nerve in wrestlers were effective in increasing hamstring flexibility and functional flexibility and not superior to each other.

This study aimed to determine whether foam roller with vibration (FRV) can improve hamstring flexibility and jump performance in young adults. Twenty subjects were randomly allocated into either the FRV or the foam- roller with no vibration (FRNV) groups. The vibration of the vibration foam-roller was 32 Hz. All participants completed one 10-min session on the hamstring. Active straight leg raising (ASLR) test in supine posi-tion and active knee extension (AKE) test in sitting position were per-formed to measure hamstring flexibility, before and immediately after the session. ASLR, AKE, and vertical jump performance test were per-formed before the session and immediately after the session. Analysis of covariance was used to determine statistical significance. ASLR and AKE tests were significantly different between FRV and FRNV, except the right hamstring. There was significant improvement with respect to ASLR and AKE tests after the session in FRV group. The vertical jump perfor-mance test of both groups was not significantly different after the ses-sion. FRV is more effective than FRNV for improving hamstring flexibility.

The purpose of this study was to investigate the effects of extracorporeal shock wave therapy on asymmetric hamstring and back pain in patients with non-specific chronic back pain. Twenty-nine subjects with nonspecific chronic low back pain were classified into experimental group (n=15) and control group (n=14). Outcome measures included hamstring length, hamstring length difference, compensative lumbar flexion and rotation, hamstring thickness, disability index, and pain intensity. The experimental group performed extracorporeal shock wave and stretching technique twice a week for three weeks, and the control group performed the stretching technique twice a week for three weeks. Extracorporeal shock waves applied 4 pressure (0.37 mJ/mm), and 2,000 shocks to the hamstring with 10 Hz. Stretching techniques are applied after extracorporeal shock wave therapy. There was a significant difference of dependent variables in the experimental group, and in the control group, there was a significant difference except for lumbar rotation. In between-group comparison, the experimental group showed signifiacnlty greater lumbar flexion and thickness of biceps femoris compared to the control group. Based on these results, we recommend extracorporeal shock wave therapy as an intervention that can reduce compensatory lumbar rotation and lengthen shortened hamstrings.

This study aimed to identify alterations in the thickness of the hamstring and the muscle tone in response to soft tissue mobilization (STM), passive stretching (PS), and muscle energy technique (MET). Forty-five male subjects with no orthopedic or neurological diseases volunteered to participate in the study, which were allocated either the SEM, PS, or MET groups, 10 in each. Outcome measure included the thickness and muscle tone of the hamstring. Intervention was an isometric contraction and 10-sec stretching for the STM group, a 10 repetitions of 10-sec stretch for the PS group, and an isometric contraction and relaxation for the MET group. Pre- and post-treatment changes in the thickness and muscle tone of hamstring were significantly different for the three groups (p<.05). However, there were not found statistically significant differences in the thickness and muscle tone of hamstring between the groups (p>.05). This study suggests that all tree methods may be helpful to increase the condition of hamstring. Further studies with robust design will be needed for the generality of our results.

본 연구는 수동적 불충분 스트레칭 적용에 따른 관절의 가동 범위와 햄스트링 근육의 근활성도를 분석하는데 연구 의 목적이 있다. 이를 위하여, 대학에 재학하고 있는 체육 계열 학생들로 편의표본추출 방법(Convenience Sampling Method)에 의해 표본을 추출하였고, 고관절 굴곡 운동 시 햄스트링 근육을 스트레칭 하는데 정형외과적 질환이 없는 학생 18명을 연구 대상으로 선정하였다. 스트레칭 유형별 사전 사후의 관절 가동 범위와 햄스트링 근육의 근활성도를 측정하였고 측정결과는 반복측정분산 분석을 사용하였다. 연구 결과는 다음과 같다. 첫째, 보편적 스트레칭과 수동적 불충분 스트레칭 유형에 따른 관절의 가동 범위는 통계적으로 유의한 차이가 나타났다. 관절의 가동 범위는 집단 간의 차이는 유의하지 않았지만, 집단과 측정 시점 간의 상호작용에 대한 주 효과가 유의하게 나타나 수동적 불충분 스트레칭이 보편적 스트레칭에 비해 관절의 가동 범위를 증가 시켜주는 것으로 나타났다. 둘째, 보편적 스트레칭과 수동적 불충분 스트레칭 유형에 따른 반건양근의 근활성도와 대퇴이두근의 근활성도는 통계적으로 유의한 차이가 나타나지 않았다.

The purpose of this study is to analyze the range of motion of joints and muscle activity of hamstring muscles according to the application of passive insufficient stretching. For this purpose, a sample was extracted from college students majoring in physical education using the convenience sampling method, and eighteen students without orthopedic conditions were selected as the subjects for a study on stretching the hamstring muscles during hip flexion. The range of motion of the joint and the muscle activity of hamstring before and after stretching for each type of stretching were measured, and the measurement results were analyzed using repeated measures analysis of variance. The research results are as follows: First, there was a statistically significant difference in the range of motion of the hip joint according to the type of universal stretching and passive insufficient stretching. Although there was no significant difference between groups in the range of motion of the joint, a significant main effect for the interaction between group and measurement time was observed, indicating that passive insufficient stretching increased the range of motion of the joint compared to universal stretching. Second, there was no statistically significant difference in the muscle activation of the semitendinosus and the biceps femoris according to the type of universal stretching and passive insufficient stretching.

Purpose: We investigated the effects of the hold-relax and foam roller techniques on the range of motion, flexibility, and tone of shortened hamstring muscles. Method: The study included 24 participants who were randomly categorized into hold-relax and foam roller groups. Both groups performed the assigned task thrice a week for a total of 5 sets of 15 s each on the hamstring muscles for 6 weeks. Range of motion was evaluated using a goniometer, flexibility was evaluated using the sit and reach test, and muscle tone was measured using a myotone. We evaluated joint range of motion, flexibility, and muscle tone pre- and 6 weeks post intervention in both groups. Results: We observed a significant intergroup difference in range of motion and flexibility after 6-week training. Conclusion: The hold-relax technique was more effective than the foam roller technique for stretching exercise to improve range of motion and flexibility of shortened hamstring muscles.

Background Jack-knife stretching is a newly developed static hamstring stretching exercise. However, no studies have compared this stretching exercise to hamstring stretching with proprioceptive neuromuscular facilitation (PNF). Purpose This study compared the effects of PNF hamstring stretching and jack-knife stretching on hamstring flexibility. Study design Randomized controlled clinical trial Methods Twenty-four adults with bilateral hamstring tightness were randomly assigned to the PNF hamstring stretching or jack-knife stretching group. All participants performed PNF hamstring stretching or jack-knife stretching for 150 s. Before and after hamstring stretching, the participants completed the active knee extension (AKE), active straight leg raise (ASLR), and finger-to-floor distance (FFD) tests. Lumbar flexion and the anterior pelvic tilt angle were measured during the FFD test. Results Both hamstring stretching exercises increased the knee extension angle during the AKE test, hip flexion angle during the ASLR test, and lumbar flexion and anterior pelvic tilt angle during the FFD test while decreasing the FFD value (p<0.05). However, no significant between-group differences were found (p>0.05). Conclusions PNF hamstring stretching and jack-knife stretching have similar beneficial effects on hamstring flexibility.

Background In clinical settings, a pressure biofeedback unit (PBU) is sometimes used to detect pelvic movement and retrain movement patterns during lower limb movement. Hamstring length influences changes in pelvic movement during passive straight leg raising (PSLR). Purpose To determine the relationship between pelvic motion and biofeedback pressure measured by a PBU during PSLR, and to identify changes in biofeedback pressure after hamstring stretching. Study design Cross-sectional study Methods Twenty participants with short hamstrings were recruited for this study. A three-dimensional motion analysis system and PBU were used to measure pelvic angle and biofeedback pressure during PSLR, respectively. The pelvis angle and biofeedback pressure were measured before and after hamstring stretching, increasing PSLR in 10-degree increments. Results There was a significant relationship between pelvic motion and biofeedback pressure (Pearson’s r=0.76, p<0.05). Linear regression equation using lumbopevic angle as an independent factor was as follows: Pressure of PBU=45.05+(3.35×angle of lumbopelvic motion) (R2=0.57, p<0.05). Biofeedback pressure decreased significantly between PSLR angles of 10?60° after hamstring stretching (p<0.05). The pelvic angle decreased significantly at PSLR angles of 50° and 60° after hamstring stretching (p<0.05). Conclusions Biofeedback pressure measured with a PBU can be used to assess pelvic motion during muscle length tests following hamstring stretching.

ABSTRACT Background Hamstring tightness is a major cause of low back pain (LBP). The active knee extension (AKE) test is frequently used to measure hamstring tightness in supine-positioned subjects. In patients with musculoskeletal pain, it is important to maintain the axis of rotation for accurate range of motion assessment. Purpose The purpose of this study was to investigate the intrarater test-retest reliability of an AKE test with belt-guided inferior gliding of the hip, which was designed to minimize excessive anterior-superior gliding of the hip in LBP patients with hamstring tightness. We also compared the range of AKE with versus without inferior gliding of the hip in this study population. Study design Reliability study. Methods Thirty-eight patients with LBP and hamstring tightness were recruited to this study. Hamstring tightness was measured in a supine AKE test, with and without inferior gliding of the hip, using the Smart KEMA device. Test?retest reliability was assessed by the intraclass correlation coefficient (ICC). Significant differences in the range of AKE between the groups were detected using a paired sample t-test. Results The hamstring flexibility tests with and without inferior gliding of the hip exhibited good to excellent test-retest reliability (ICC=0.89 for both). The range of AKE with inferior gliding of the hip was significantly less than that of AKE without inferior gliding of the hip. Conclusions Assessment of hamstring flexibility via an AKE test with inferior gliding of the hip is reliable when applied to patients with LBP; the range of AKE was lower in this test compared to those that do not incorporate inferior gliding of the hip.

Objective To investigate the effect of adding Nordic exercise as post-training in decreasing hamstring initial, recurrent injuries rates, and their severity. Methods In this randomly controlled trial study, 34 professional football players aged 21 to 35 years were randomly assigned into two groups (17 players each) from Sporting clubs at Alexandria, Egypt. For group one, Nordic hamstring exercise (NHE) was performed pre-training and post-training. For group two, NHE was only performed pre-training. The control group was the same team during the previous season. Length of the trial was 12 weeks. The Australian football association injury form was used to collect incidence of injuries for each subject in both groups. Results Pooled results based on total injuries showed that group one had significantly less hamstring initial injuries (92% less) than the previous season, while group two had 80% less initial injuries and 85% less recurrent injuries than previous season. Regarding the severity of injuries in term of mean number of absent days, it was 1 day for group one and 2.7 days for group two while it was 7.95 days for the previous season during total risk time of 116.3±13.2 and 117.6±5.7 exposure hours for group one and group two, respectively. Conclusion The use of NHE as a prevention protocol was effective in reducing all hamstring injuries with the use of NHE during pre-training and post-training having the greatest effect.

Background Two different neurodynamic techniques have been suggested: (i) the slider (ii) the tensioner. However, the effects of slider and tensioner on hamstring flexibility during forward bending have not been directly compared. Purpose This study aimed to compare the immediate effects of slider and tensioner on forward bending in asymptomatic subjects with hamstring tightness. Study design Two groups pre- and post-test design Methods Twenty male subjects with hamstring tightness participated in this study. The subjects were randomly allocated to the slider and tensioner groups, consisting of 10 participants each. To measure hip and lumbar flexion during forward bending, a smart motion sensor was employed. The paired t-test was applied to compare pre- and post-intervention within each group. The independent t-test was used to compare the hip and lumbar flexion angles between the two groups. Results Intragroup comparison found that the slider group had a significant increase in hip flexion range of motion at post-intervention. Intergroup comparison found a significant greater change in hip flexion range of motion between pre- and post-intervention in slider group. Conclusions Based on the results of this study, it was found that sliders are more effective than tensioners in enhancing hamstring flexibility during forward bending in subjects with hamstring tightness.

This study investigates the effect of vibration foam roller (VFR) applied to the hamstring, on the quadriceps electromyography (EMG) activity and hamstring flexibility. A total of 16 subjects were randomly assigned to either the VFR group (n=8) or the nonvibration foam roller group (NVFR, n=8). The two groups applied the foam roller or the VFR to the dominant hamstring, at a rate of 40 times per min, for a total of 200 times in 5 min. The primary outcome was to measure hamstring extensibility using the sit and reach test. The EMG activity of the dominant rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) was mea-sured as the secondary outcome. Results indicate a significant in-crease in the sit and reach distance after the intervention in both groups, as compared to preintervention. The sit and reach difference between VFR and NVFR show no significant difference after the inter-vention. Significant increases were observed after intervention in the %maximum voluntary isometric contraction (%MVIC) of VL, VM, and RF in the VFR group, and RF in the NVFR group, as compared to the prein-tervention values. Furthermore, %MVIC values of VL and RF, but not the VM muscle, were significantly different between the two groups. These findings suggest that regardless of vibration, the application of foam roller to hamstring may exert a positive effect on hamstring flexibility. Furthermore, these results indicate that the application of foam roller with vibrations causes more EMG activation in the antagonists.

Purpose: This study aims to examine the pain, muscle characteristic, Flexion-Relaxation Phenomenon to the hamstring flexibility. Methods: This study has as its subjects 105 Chronic Low Back Pain patients and divides them into the group (HHF n=52) with the normal length of hamstrings according to AKE test and the group (HLF, n=53) tending to have shortened hamstrings. AKE (active knee extension) Test was conducted to evaluate the degree of hamstring flexibility. And to examine the pain, muscle characteristic, Flexion-Relaxation Phenomenon it was compared and analyzed by using the VAS, myotonePRO, SEMG Results: HHF showed more significant difference than HLF in the analysis on the muscle characteristic (p<.05). Conclusion: According to the analysis, the shortening of hamstrings is the factor that affects the muscle characteristic but Chronic pain, Flexion-Relaxation Phenomenon not affects

Purpose: Low back pain, a common musculoskeletal disorder, is impacted by shortening of the hamstring. Lumbar stabilization exercises are frequently used to treat low back pain. Therefore, this study aimed to investigate the effects of hip abduction angle on medial and lateral hamstring muscle activity during bridge exercise and pelvic posterior tilting exercise. Methods: Thirty-six individuals with herniated intervertebral disk (HIVD) participated in this study. All subjects performed the bridge exercise and pelvic posterior tilting exercise for twelve seconds. While the participants maintained these exercise positions, hamstring muscle activation was measured for each leg. Specifically, dynamic surface electromyography was utilized to compare muscle activity for the biceps femoris and the semitendinosus muscle groups in both affected and non-affected hamstrings. An independent t-test was used to identify the impact of exercise type or symptom presentation on hamstring muscle activity. The data was analyzed using PASW Statistics 18.0 (SPSS Inc, USA). Results: Overall, our results indicated that there was no significant difference in hamstring muscle activation as a consequence of exercise type (p>0.05). This result was observed regardless of the hip joint abduction angle (0° and 30°). However, when participants conducted the bridge exercise while in the hip joint 0° abduction position, muscle activation of both the biceps femoris and the semitendinosus was significantly lower on the affected side than that on the non-affected side (p<0.05). Conclusion: Consequently, performing bridge exercise and pelvic posterior tilting exercises with abducted hip joints may be helpful in the balanced development of the hamstring.

The nordic hamstring exercise (NHE) is a dynamic lengthening ham-string exercise that requires trunk and hip muscles activation. Thigh muscles activation, specifically hamstring/quadriceps contractions has been previously examined during NHE. Trunk and hip muscles activity have not been enough studied. The aim of this study was to analyze of hip and trunk muscles activity during NHE. Surface electromyography (EMG) and kinematic data were collected during NHE. Ten healthy men with the age range of 21–36 years performed two sets of two repetitions with downward and upward motions each of NHE. EMG activity of fif-teen trunk and hip muscles and knee kinematic data were collected. Muscle activity levels were calculated through repeated measure anal-ysis of variance in downward and upward motions, through Paired t-test between downward and upward motions and gluteus maximus to erector spine activity ratio (Gmax/ES ratio) using Pearson correlation analyses were evaluated. Semitendinosus and biceps femoris muscles activity levels were the greatest in both motions and back extensors and internal oblique muscles activity were greater than other muscles (P<0.05). The decreased Gmax/ES ratio was significantly related to peak knee extension angle in downward (r=0.687) and upward motions (r=0.753) (P<0.05). These findings indicate the importance of synergis-tic muscles and trunk muscles coactivation in eccentric and concentric hamstrings contractions. It could be important for early assessment of subjects with hamstring injury risk.

This study evaluated the effects of repeated, self-administered hamstring muscle stretching on activation of the erector spinae muscles in chronic low back pain patients. The study was performed on 24 patients with no other diagnosis or history of surgical treatment. Volunteers with right-sided back pain were recruited. All subjects performed 3 sets of self-administered hamstring muscle stretching exercises 10 times daily, in each of 3 directions. After the intervention, static and dynamic muscle activity of the erector spinae muscles was measured with the MyoVision 3G Wirefree system. Static muscle activation significantly changed after intervention at C7, T3, and T1 on the right side and at C4, T3, T6, T9, and T10on the left side. In addition, dynamic muscle activation for right side flexion-peak and flexionminchanged significantly after intervention. We conclude that self-administered hamstring stretching can indirectly reduce erector spinae muscle activation.

Injuries to the hamstring muscles are common in athletes. Track and field, Australian football, American football and soccer are examples of sports where hamstring injuries are the most common. The purpose of this study was to investigate whether there is a correlation between a hamstring injury prognosis and its characteristics of imaging parame-ters. The literature search was performed in the databases PubMed and CINAHL, and eleven articles were included. Seven out of the 11 ar-ticles showed a correlation between the size of the hamstring injury and length of time required before returning to sports. Different authors have reported contrasting results about length of time required before returning to sports due to location of injury within specific muscle. Ma-jority of the articles found hamstring strain correlated to an extended amount of time required before returning to sports.

The purpose of this pilot case study is to investigate the effects of Pi-lates training on hamstring/quadriceps ratio, trunk strength, shoulder strength, and body composition in adolescent baseball players. Eight adolescent baseball players, 15 years of age, participated in Pilates program (supervised training, 50 min per session for three times a week for 8 weeks) using reformer and Cadillac. The intensity of the program was progressively increased by applying beginner level for 1–2 weeks, intermediate level for 3–6 weeks, and advance level for 7–8 weeks. To verify the effect of the Pilates program on hamstring/quadriceps ratio, trunk strength, shoulder strength and body composition, participants performed bioelectrical impedance analysis and isokinetic testing at pre- and posttraining. After the Pilates training, there were significant increases in body weight (P<0.01), left arm muscle mass (P<0.01), and trunk muscle mass (P<0.01). In addition, there were significant increas-es in left and right knee flexion peak torque (P<0.01 and P<0.05, re-spectively), right knee extension peak torque (P<0.05), left and right hamstring/quadriceps ratio (both P<0.01), trunk flexion peak torque (P<0.05) and shoulder flexion peak torque (P<0.05) after 8 weeks of training. Therefore, Pilates training increased muscle mass, hamstring/quadriceps ratio, trunk and shoulder strength, suggesting that it may help baseball players do better performance and prevent future injuries in adolescent players.

Purpose: This study investigated the effects of changing the tilt angle of the exercise bed on physiological characteristics of trapezius, multifidus, and hamstring muscle function. Methods: Twenty elderly who complains of back and lumbar pain or discomfort participated in this study (average age: 64.70±4.55 years). The physiological characteristics, including muscle tone (F), dynamic stiffness (S), and elasticity (D) of trapezius, multifidus, and hamstring muscles were measured by a Myoton device at three tilt angles (0, 15, and 30 degrees) during exercise. Results: The muscle tone, dynamic stiffness, and elasticity of the right trapezius and left hamstring muscle showed significant differences (p<0.05) according to exercise bed tilt angle, while the other muscles showed no significant differences. Conclusions: Our results demonstrate that physiological characteristics of the upper and lower extremity muscles are affected ipsilaterally, according to the tilt angles of the exercise bed.