Effects of Different Physical Therapy Interventions in Improving Flexibility in University Students with Hamstring Tightness - A Systematic Review and Network Meta-analysis

The aim of the present study was to identify the different interventions for hamstring flexibility among university students with hamstring tightness and to determine the better treatment method.

Design

Systematic review and network meta-analysis. An electronic search of the databases: Medline, Pubmed, Cochrane, EMBASE, CINAHL, Physiotherapy Evidence Database (PEDro) was conducted. A total of 11 articles were included in the review. Of these articles, 02 were case-control studies, 02 were interventional pre-post studies and 07 were RCTs. The 07 RCTs were included for network meta-analysis. The findings of the initial network meta-analysis (NMA) which compared control i.e., no intervention with other interventions revealed that all the physical therapy interventions: stretching, electrotherapy combined with stretching, massage, dry needling and neurodynamic exercises combined with stretching and neurodynamics alone were superior to control. Since most studies included stretching as an intervention, a second NMA was conducted to compare the different physical therapy interventions with stretching. The results suggested that US-guided neuromodulation (WMD: -5.80, CI: -12.11, 0.51) had large effects on hamstring flexibility compared to stretching and stretching combined with electrotherapy i.e., cryotherapy and ultrasound (WMD: 0.25, CI: -1.14 to 1.64), MET (WMD: 3.10, CI: -3.28 to 9.48) and massage (WMD: 8.05, CI: -11.90 to 27.18) were inferior to stretching. To further investigate the effects of these interventions three meta-analysis were performed. The results revealed that stretching was more effective (SMD 2.27, 95% 0.72 to 3.81, p < 0.01) compared to control (no intervention). Neurodynamic exercises combined with stretching and neurodynamics alone were found to be superior to stretching alone ((SMD -0.69, 95% -1.35 to -0.03, p < 0.01) and stretching combined with electrotherapy was not significantly better than stretching alone ((SMD -0.07, 95% -1.00 to 0.87, p=0.88). Neurodynamic exercises combined with stretching and neurodynamics alone showed to be superior to the other physical therapy interventions in improving hamstring flexibility for hamstring tightness among university students, however, the reliability of the evidence is low.

Comparing right and left hamstring flexibility and its association to nonspecific lowr back pain among women of different age groups

BACKGROUND AND OBJECTIVES

Decreased hamstring flexibility has been associated with LBP (lower back pain). Increased tightness or shortening of hamstring muscle may cause pelvis imbalance or tilt and create instability and increase LBP risk. This study was conducted to pinpoint the differences between right and left hamstring length and their association to LBP in Israeli adult and elderly women.

METHODS

N = 109 women which were divided into two groups: Adult group, 41 women (aged 45-60) and older group, 68 women (aged 60-75), with LBP that exercise regularly (minimum twice weekly) were selected based on inclusion criteria. Hamstring flexibility was measured using the Passive Straight Leg Raise test and Sit and Reach test, and LBP was measured using the Oswestry Disability Index (OS), the Roland-Morris questionnaire (RM), and a personal information questionnaire.

FINDINGS

Findings indicate a statistically significant difference (p < .05) in hamstring flexibility between right and left legs in PSLR test, with the left being shorter than the right. A significant negative correlation was found between hamstring shortening to function in OS and RM questionnaires in the older group, no significant correlation was found between left -right hamstring flexibility differences and reduced function with LBP in the OS and RM questionnaires.

CONCLUSION

s: Hamstring shortening in adult and elderly women exists despite regular exercise. Future studies must be incorporated to improve hamstring flexibility with emphasis on balance of left and right legs to examine how this will affect LPB reports and compare women who exercise versus women who do not.

Risk factors for hamstring strain injury in male college American football players -a preliminary prospective cohort study

BACKGROUND

Given the frequency of hamstring strain injuries (HSI) among male college American football players, several studies have attempted to determine whether certain risk factors can predict their occurrence. However, no consensus on modifiable risk factors for HSIs in male college American football players has yet been reached to prevent these injuries. This study aimed to clarify risk factors for HSI prospectively in college male American football players.

METHODS

A total of 78 male college American football players, whose positions were limited to skill positions, were medically assessed for potential risk factors of HSI. The preseason medical assessment included anthropometric measurements, joint laxity and flexibility, muscle flexibility, muscle strength, and balance ability.

RESULTS

HSI occurred in a total of 25 thighs from 25 players (32.1%). Injured players had significantly lower hamstring flexibility (p = 0.02) and hamstring to quadriceps strength ratio (H/Q) (p = 0.047) compared to uninjured players. Additionally, injured players had significantly lower general joint laxity scores, especially for the total (p = 0.04), hip (p = 0.007), and elbow (p = 0.04) scores, compared to uninjured players.

CONCLUSIONS

Lower hamstring flexibility, lower hamstring to quadriceps strength ratio, and lower general joint laxity score were identified as risk factors for HSI in male college American football players placed in skill positions. The muscle flexibility and H/Q ratio could be useful in preventing HSI in such players.

Immediate effects of static and proprioceptive neuromuscular facilitation stretching of hamstring muscles on straight leg raise, craniovertebral angle, and cervical spine range of motion in neck pain patients with hamstring tightness: A prospective randomized controlled trial

BACKGROUND

The cranio-cervical flexion exercise and sub-occipital muscle inhibition technique have been used to improve a forward head posture among neck pain patients with straight leg raise (SLR) limitation. However, little is known about the cranio-vertebral angle (CVA) and cervical spine range of motion (CROM) after applying stretching methods to the hamstring muscle.

OBJECTIVE

To compare the immediate effects of static stretching and proprioceptive neuromuscular facilitation stretching on SLR, CVA, and CROM in neck pain patients with hamstring tightness.

METHODS

64 subjects were randomly allocated to the static stretching (n1= 32) or proprioceptive neuromuscular facilitation (n2= 32) stretching group. The SLR test was performed to measure the hamstring muscle's flexibility and tightness between the two groups, with CROM and CVA also being measured. The paired t-test was used to compare all the variables within each group before and after the intervention. The independent t-test was used to compare the two groups before and after the stretching exercise.

RESULTS

There were no between-group effects for any outcome variables (P> 0.05). However, all SLR, CVA, and CROM outcome variables were significantly improved within-group (P< 0.05).

CONCLUSIONS

There were no between-group effects for any outcome variable; however, SLR, CVA, and CROM significantly improved within-group after the one-session intervention in neck pain patients with hamstring tightness.

The effects of vibration foam roller applied to hamstring on the quadriceps electromyography activity and hamstring flexibility

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 measured as the secondary outcome. Results indicate a significant increase 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 intervention. 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 preintervention 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.

ACUTE EFFECTS OF NEURAL GLIDING ON ATHLETIC PERFORMANCE

BACKGROUND

Neural mobilization has been used to treat individuals with musculoskeletal and neuromuscular pathologies, but research on neural mobilization in sports rehabilitation is scarce. Furthermore, there have been no studies investigating the effects of neural gliding on sport performance.

PURPOSE/HYPOTHESIS

The purpose of this study was to examine the differences between the acute effects of sciatic nerve gliding and lower extremity dynamic stretching exercises on hamstring flexibility and athletic performance.

STUDY DESIGN

A cross-sectional, quasi-experimental design with block assignment was used.

METHODS

Twenty-seven (16 males, 11 females, age: 23.6 ± 2.65, height (m): 1.74 ± 0.12, weight (kg): 73.73 ± 16.09) healthy college students volunteered for the study. The neural gliding group had 14 subjects and the dynamic stretching group had 13 subjects. Participants performed a jogging or walking up stairs warm up at a self-selected pace prior to testing. Baseline data was obtained for each of the following measurements: bilateral hamstring flexibility using the active straight leg raise test measured by a digital inclinometer, vertical jump height, 20-yard shuttle run and 10 and 20-yard dash sprint. The participants then performed one of the assigned five-minute stretching protocol, bilateral sciatic neural gliding or dynamic stretching of the lower extremities, followed by the post-test data collection of the same measures.

RESULTS

There were no significant group by time interaction for any of the six measurements (2 x 2 repeated measures ANOVA). However, significant time differences, pre-test vs post-test for all participants as one group, for right hamstring length (p = .001), left hamstring length (p = .002) and vertical jump (p = .028) were observed. Post hoc paired t-tests found a significant increase between the pre and post-tests in right hamstring flexibility, (p = .011) in the dynamic stretching group and left hamstring flexibility of participants in the neural gliding condition, (p = .004). When analyzing the groups individually, pre-test vs post-test, a significant difference in vertical jump was not observed in either group.

CONCLUSION

Similar improvement in hamstring flexibility with both dynamic stretching and neural gliding exercises without a negative effect on three sports performance tests was demonstrated. Therefore, athletic performance will not be negatively affected by a pre-participation warm-up which includes neural gliding, but more research is needed.

LEVEL OF EVIDENCE

Level 3.

Neural gliding and neural tensioning differently impact flexibility, heat and pressure pain thresholds in asymptomatic subjects: A randomized, parallel and double-blind study

OBJECTIVE

To compare the effect of neural gliding and tensioning on hamstring flexibility, nerve function (heat and cold thresholds) and pain sensitivity (pain intensity and pressure pain threshold) of the mobilized and non-mobilized lower limbs at post-intervention and 24 h follow up.

DESIGN

Randomized, parallel and double blinded trial.

SETTING/PARTICIPANTS

Forty-eight asymptomatic participants.

INTERVENTION(S)

Participants received neural gliding (n = 23) or tensioning (n = 25). Main Outcome Measures - Straight leg raising (SLR; in degrees), heat and cold threshold (ºC), pressure pain threshold (PPT; in Kgf) and pain intensity (visual analogue scale), taken at baseline, post-intervention and at 24 h follow up.

RESULTS

There was a significant interaction between time, intervention and limb for SLR (F2,45 = 3.83; p = 0.029). A significant interaction between time and intervention for PPT (F2,45 = 3.59; p = 0.036) and heat threshold (F2,45 = 5.10; p = 0.01). A significant effect of time (F2,45 = 9.42; p < 0.001) and of limb (F1,46 = 4.78; p = 0.035) for pain intensity during SLR, and a significant effect of time (F2,45 = 3.65; p = 0.034) for pain intensity during PPT.

CONCLUSION

Gliding and tensioning had similar and positive effects for flexibility in the mobilized limb, but tensioning was superior for the non-mobilized limb. Gliding was superior to tensioning for pressure pain and heat thresholds.

The effect of hamstring flexibility on peak hamstring muscle strain in sprinting

BACKGROUND

The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting, until now, remained unknown, which limited our understanding of risk factors of hamstring muscle strain injury (hamstring injury). As a continuation of our previous study, this study was aimed to examine the relationship between hamstring flexibility and peak hamstring muscle strains in sprinting.

METHODS

Ten male and 10 female college students participated in this study. Hamstring flexibility, isokinetic strength data, three-dimensional (3D) kinematic data in a hamstring isokinetic test, and kinematic data in a sprinting test were collected for each participant. The optimal hamstring muscle lengths and peak hamstring muscle strains in sprinting were determined for each participant.

RESULTS

The muscle strain of each of the 3 biarticulated hamstring muscles reached a peak during the late swing phase. Peak hamstring muscle strains were negatively correlated to hamstring flexibility (0.1179 ≤ R 2 ≤ 0.4519, p = 0.001) but not to hip and knee joint positions at the time of peak hamstring muscle strains. Peak hamstring muscle strains were not different for different genders. Peak muscle strains of biceps long head (0.071 ± 0.059) and semitendinosus (0.070 ± 0.055) were significantly greater than that of semimembranosus (0.064 ± 0.054).

CONCLUSION

A potential for hamstring injury exists during the late swing phase of sprinting. Peak hamstring muscle strains in sprinting are negatively correlated to hamstring flexibility across individuals. The magnitude of peak muscle strains is different among hamstring muscles in sprinting, which may explain the different injury rate among hamstring muscles.

Physical performance of elite and subelite Spanish female futsal players

The aim of this study was to determine the parameters distinguishing top female futsal players from lower level players. Twenty-seven female futsal players participated in the study, composed of professional first division (elite; n = 15) players and semi-professional second division players (sub-elite; n = 14). Active and passive straight leg raise tests, isokinetic strength of the knee extensor and flexor muscles at 60° · s(-1) angular velocity, squat and counter movement jumps, 30 m sprint, 30 m agility, repeated sprint ability test and maximum ball speed during shooting were measured. The elite players were more agile and kicked harder than sub-elite players in maximum ball speed during the shooting test (P ≤ 0.05). However, no significant differences between teams were observed in active and passive hamstring flexibility, jumping ability, repeated sprint ability test, 30 m sprint time, H/Q ratio and absolute and relative torque from 60° · s(-1) angular velocity. Based on these findings we conclude that agility and maximum ball speed during shooting may be important determinant factors of Spanish female futsal actions and could distinguish ability at high-level games.

Immediate effect of passive and active stretching on hamstrings flexibility: a single-blinded randomized control trial

[Purpose] This study compared the efficacy of passive and active stretching techniques on hamstring flexibility. [Subjects] Fifty-four healthy young subjects were randomly assigned to one of three groups (2 treatment groups and 1 control group). [Methods] Subjects in the passive stretching group had their knees extended by an examiner while lying supine 90° of hip flexion. In the same position, subjects in the active stretching group extended their knees. The groups performed 3 sets of the assigned stretch, with each stretch held for 10 seconds at the point where tightness in the hamstring muscles was felt. Subjects in the control group did not perform stretching. Before and immediately after stretching, hamstring flexibility was assessed by a blinded assessor, using the active knee-extension test. [Results] After stretching, there was a significant improvement in the hamstring flexibilities of the active and passive stretching groups compared with the control group. Furthermore, the passive stretching group showed significantly greater improvement in hamstring flexibility than the active stretching group. [Conclusion] Improvement in hamstring flexibility measured by the active knee-extension test was achieved by both stretching techniques; however, passive stretching was more effective than active stretching at achieving an immediate increase in hamstring flexibility.

Short term effectiveness of neural sliders and neural tensioners as an adjunct to static stretching of hamstrings on knee extension angle in healthy individuals: A randomized controlled trial

OBJECTIVE

To investigate the added benefit of nerve-biased interventions over static stretching in hamstring flexibility and to compare the effectiveness of two types of nerve-biased interventions over a week.

DESIGN

Three-arm assessor-blinded randomized controlled trial.

SETTING

University Laboratory.

PARTICIPANTS

Sixty healthy individuals (mean age = 22 ± 2.4 years) with reduced hamstring flexibility were randomized to three groups who received static stretching and neurodynamic sliders (NS-SS); static stretching with neurodynamic tensioner (NT-SS) and static stretching (SS) alone.

OUTCOME MEASURE

Knee extension angle (KEA) in degrees.

RESULTS

Baseline characteristics including demographic, anthropomorphic and KEA between groups were comparable. A significant interaction was observed between group (intervention) and time, [F (2,114) = 3.595; p = 0.031]. Post-hoc pairwise comparisons analyses revealed significant differences at post-intervention measurement time point between NS-SS and SS (mean difference: -6.8; 95%CI = -12, -1.5; p = 0.011) and NT-SS and SS (mean difference: -11.6; 95%CI = -16.7, -6.3; p < 0.001). However there was no significant difference between NS-SS and NT-SS groups (mean difference: 4.8; 95%CI = 0.4, 9.9; p = 0.074).

CONCLUSIONS

Neural sliders and tensioners are both effective in increasing hamstring flexibility as an adjunct to static hamstring stretching when compared to static stretching alone. No neural mobilization technique proved to be superior over another.

CLINICAL TRIAL REGISTRATION

This clinical trial is registered in Clinical Trials Registry- India (CTRI) with registration number CTRI/2012/05/002619.

Lumbar Extension during Stoop Lifting is Delayed by the Load and Hamstring Tightness

[Purpose] This study investigated the relationship between lumbar pelvic rhythm and the physical characteristics of stoop lifting. [Subjects and Methods] Participants performed a stoop lifting task under two conditions: with and without load. We assessed the lumbar kyphosis and sacral inclination angles using the SpinalMouse^® system, as well as hamstring flexibility. During stoop lifting, surface electromyograms and the lumbar and sacral motions were recorded using a multi-channel telemetry system and flexible electrogoniometers. [Results] In the initial phase of lifting, lumbar extension was delayed by load; the delay showed a negative correlation with sacral inclination angle at trunk flexion, whereas a positive correlation was observed with electromyogram activity of the lumbar multifidus. Additionally, a positive correlation was observed between sacral inclination angle and hip flexion range of motion during the straight leg raise test. [Conclusion] We found that a disorder of the lumbar pelvic rhythm can be caused by both load and hamstring tightness. In the initial phase of stoop lifting, delayed lumbar extension is likely to lead to an increase in spinal instability and stress on the posterior ligamentous system. This mechanism shows that stoop lifting of a load may be harmful to the lower back of people with hamstring tightness.