Acute effect of electrical muscle elongation and static stretching in hamstring muscle extensibility

Acute Effects of Various Stretching Techniques on Range of Motion: A Systematic Review with Meta-Analysis

Background

Although stretching can acutely increase joint range of motion (ROM), there are a variety of factors which could influence the extent of stretch-induced flexibility such as participant characteristics, stretching intensities, durations, type (technique), and muscle or joint tested.

Objective

The objective of this systematic review and meta-analysis was to investigate the acute effects of stretching on ROM including moderating variables such as muscles tested, stretch techniques, intensity, sex, and trained state.

Methods

A random-effect meta-analysis was performed from 47 eligible studies (110 effect sizes). A mixed-effect meta-analysis subgroup analysis was also performed on the moderating variables. A meta-regression was also performed between age and stretch duration. GRADE analysis was used to assess the quality of evidence obtained from this meta-analysis.

Results

The meta-analysis revealed a small ROM standard mean difference in favor of an acute bout of stretching compared to non-active control condition (ES = −0.555; Z = −8.939; CI (95%) −0.677 to −0.434; p  < 0.001; I2 = 33.32). While there were ROM increases with sit and reach (P  = 0.038), hamstrings (P  < 0.001), and triceps surae (P  = 0.002) tests, there was no change with the hip adductor test (P  = 0.403). Further subgroup analyses revealed no significant difference in stretch intensity (P  = 0.76), trained state (P  = 0.99), stretching techniques (P  = 0.72), and sex (P  = 0.89). Finally, meta-regression showed no relationship between the ROM standard mean differences to age (R2 = −0.03; P  = 0.56) and stretch duration (R 2 = 0.00; P  = 0.39), respectively. GRADE analysis indicated that we can be moderately confident in the effect estimates.

Conclusion

A single bout of stretching can be considered effective for providing acute small magnitude ROM improvements for most ROM tests, which are not significantly affected by stretch intensity, participants’ trained state, stretching techniques, and sex.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-023-00652-x.

The meta-analysis on joint range of motion (ROM) increases revealed a small effect size in favor of an acute bout of stretching compared to the control condition. Subgroup analysis revealed a significant increase in ROM with sit and reach, hamstrings, and triceps surae tests, but no improvement with the hip adductor tests. Whereas all moderating variables presented significant increases in ROM, further subgroup analyses revealed no significant difference in ROM gains with the stretch intensity, trained state of the participants, stretching techniques, and sex. A meta-regression showed no relationship between the effect sizes to age and stretch duration, respectively.

A Novel Method for Muscle Elongation in Myalgia with Naqvi's-Dynamic Electrical Therapy Approach (DELTA)©: The First-Ever Case Report

Lifestyle-related neck and shoulder pain can be attributed to trapezius myalgia (TM) in a significant number of cases. Apart from pain, manifestations of TM include tightness of the trapezius muscle, especially in the upper fibres. Naqvi's-Dynamic Electrical Therapy Approach (Naqvi's-DELTA)© is a novel electrotherapeutic intervention based on the principle of myofibril elongation obtained by interference of poled vector current that is moved along the length of muscle fibres. A 22-year-old male approached the physiotherapy outpatient department (OPD) with the chief complaint of persistent neck pain and stiffness for three years that adversely affected his activities of daily living (ADLs). The pain was evaluated using a visual analog scale (VAS), restrictions in the range of motion (ROM) were determined by the cervical range of motion (CROM) device, and limitations in ADLs were assessed by neck disability index (NDI). Naqvi's-DELTA© was administered once a day for seven days, with each session lasting for 15 minutes. After the intervention, an evident beneficial effect was noted in all outcomes measures suggesting that this novel method was effective in decreasing pain, stiffness, and limitations in ADLs. Further investigation to explore this method for myalgia management is warranted.

Effects of Non-Contact Corrective Exercise Continuum for 12 Weeks on Postural Imbalance in Adults

OBJECTIVES This study was to examine the effect of the 12-week video-based non-contact corrective exercise continuum (CEC) program on the forward head posture, central asymmetry, varus and valgus knees for men and women with postural imbalance.METHODS Subjects were recruited openly by the Internet community and measured their posture with a 3D whole body scanner (Medicube WS-210, Korea), and then classified into exercise group (n=32, EG) and control group (n=32, CG). Total subjects were classified into forward head posture exercise group (n=8), central asymmetry exercise group (n=8), varus exercise group (n=8), valgus exercise group and each control group (n=8). For the non-contact home training, 12 weeks of 30 minutes/day, 3 times/week, corrective exercise continuum were conducted. The CEC program is an effective treatment to correct the anatomical alignment of the extremities as suggested by the National Academy of Sports Medicine.RESULTS As a result, the distance between the centers according to the forward head posture CEC program in EG, the angle of spinal inclination of the cervical and thoracic vertebrae, and central asymmetry were lowered (p<.05). Body shape distribution balance and shoulder tilt angle were lowered in EG according to the central asymmetry CEC program (p <.05). According to the varus CEC program in EG, the distance between the center of the knee, the tilt angle of the femur and tibia, and body shape distribution were lowered (p <.05). According to the valgus CEC program in EG, the distance between the center of the knee increased, and the tilt angle of the femur and tibia decreased (p<.05).CONCLUSIONS The effect of improving the anterior head posture, central asymmetry, varus and valgus knees of postural imbalance according to the CEC program was confirmed. It is thought that the CEC program can restore optimal neuromuscular control by restoring proper joint kinematics and restore posture and balance by reducing the observed muscle tension.

Immediate and short-term radiological changes after combining static stretching and transcutaneous electrical stimulation in adults with cavus foot: A randomized controlled trial

BACKGROUND

Cavus foot is a deformity represented by an increased and rigid medial longitudinal arch, and it is often associated with persistent pain and gait disturbances. None of the conservative conventional treatments for cavus foot have shown conclusive evidence of effectiveness, and so further is research needed to understand how to manage this condition better. This study aimed to assess the immediate and short-term radiological changes after combining static stretching and transcutaneous electrical stimulation of the plantar fascia in adults with idiopathic cavus foot.

METHODS

A randomized, single-blinded clinical trial was conducted. Sixty-eight participants with idiopathic cavus foot, as determined by an internal Moreau-Costa-Bertani angle (MCBA) less than 125° in a lateral weight-bearing foot radiograph, were equally distributed into a neuromuscular stretching group (NSG) or a control group (no intervention). The NSG underwent a single session, combining transcutaneous electrical nerve stimulation with static stretching of the plantar fascia. Primary measurements of 3 angles were taken using a lateral weight-bearing foot radiograph: the internal MCBA; the calcaneal pitch angle (CPA); and the first metatarsal declination angle (FMDA). Outcomes were collected at baseline, immediately postintervention, and 1 week after intervention.

RESULTS

Analysis of variance revealed a significant group effect for all angles (all, P < .05). NSG participants showed a significant increase in the internal MCBA (P = .03), and a significant decrease in the CPA (P = .01) and FMDA (P = .04) from baseline to immediately postintervention. These changes remained statistically significant 1 week after the intervention (all, P < .05).

CONCLUSION

The combination of static stretching and transcutaneous electrical stimulation of the plantar fascia, compared with no treatment, achieved immediate and short-term changes in the internal MCBA, the CPA, and the FMDA, which resulted in flattening the medial longitudinal plantar arch in adults with idiopathic cavus foot.

Immediate effects and one-week follow-up after neuromuscular electric stimulation alone or combined with stretching on hamstrings extensibility in healthy football players with hamstring shortening

OBJECTIVE

To assess the immediate and mid-term (after 7 days) effects of electric current combined with simultaneous muscle stretching (EME technique) per comparison to the isolated use of the same current (without applying simultaneous muscle stretching), over the hamstring extensibility in football players with hamstring shortening, and to estimate the clinical benefit of the interventions according to the muscular extensibility.

METHODS

Forty-eight participants were randomized to receive one session of EME technique (n = 26) or one session of the electrical current (EC) alone (n = 22). The measurement of the hamstrings extensibility through the active knee test was carried out before and immediately after each intervention and one week later.

RESULTS

A significant interaction group x time was observed (F_2,84 = 7.112, p = 0.001; partial eta squared = 0.145). The hamstrings extensibility changed significantly immediately after the EME technique (147.3° ± 16.4° to 153.5° ± 14.2°, p < 0.05), but not after the EC only (144.2 ± 10.2° to 141.7 ± 7.8°, p > 0.05). One week after the intervention no significant differences were found to the baseline values in both groups. The number needed to treat to prevent one new case of hamstring shortening was 3.

CONCLUSION

The combination of electric current with simultaneous stretching is an effective technique to acutely increase the hamstring extensibility of football players with hamstring shortness.

Rehabilitation improves walking kinematics in children with a knee varus: Randomized controlled trial

BACKGROUND

Previous studies have demonstrated increased medial stresses in knee varus alignment. Selecting a suitable treatment strategy for individuals with knee malalignment should be a priority.

OBJECTIVES

We aimed to investigate the effects of a 16-week corrective exercise continuum (CEC) program on 3-D joint angles of the dominant and non-dominant lower limbs in children with genu varus during walking.

METHODS

Overall, 28 male children with genu varus (age range 9-14 years) volunteered to participate in this study. They were randomly divided into 2 equal groups (experimental and control). The participants of the experimental group received CEC for 16 weeks. 3-D gait analysis involved using a Vicon Motion System. Paired and independent sample t-tests were used for within- and between-group comparisons, respectively.

RESULTS

For the experimental group, comparison of pre- and post-test joint kinematics of the dominant lower limb revealed that CEC decreased the peak ankle dorsiflexion angle by 26% (P=0.020), peak foot internal rotation angle by 53% (P=0.001), peak knee internal rotation angle by 40% (P=0.011), peak hip abduction by 47% (P=0.010), and peak hip external rotation angle by 60% (P=0.001). In contrast, peak knee external rotation angle of the dominant limb was increased after the training program by 46% (P=0.044). For the non-dominant lower limb, CEC decreased the peak ankle inversion by 63% (P<0.01), peak ankle eversion by 91% (P<0.01), peak foot internal rotation by 50% (P<0.01), peak knee internal rotation by 29%; P=0.042), peak hip abduction angle by 38% (P<0.01), and peak hip external rotation angle by 60% (P<0.01).

CONCLUSIONS

CEC therapy reduced excessive foot and knee internal rotations as well as excessive hip external rotation during walking in children with genu varus.

The combined effects of transcutaneous electrical nerve stimulation (TENS) and stretching on muscle hardness and pressure pain threshold

[Purpose] This study aimed to clarify the immediate effects of a combined transcutaneous electrical nerve stimulation and stretching protocol. [Subjects] Fifteen healthy young males volunteered to participate in this study. The inclusion criterion was a straight leg raising range of motion of less than 70 degrees. [Methods] Subjects performed two protocols: 1) stretching (S group) of the medial hamstrings, and 2) tanscutaneous electrical nerve stimulation (100 Hz) with stretching (TS group). The TS group included a 20-minute electrical stimulation period followed by 10 minutes of stretching. The S group performed 10 minutes of stretching. Muscle hardness, pressure pain threshold, and straight leg raising range of motion were analyzed to evaluate the effects. The data were collected before transcutaneous electrical nerve stimulation (T1), before stretching (T2), immediately after stretching (T3), and 10 minutes after stretching (T4). [Results] Combined transcutaneous electrical nerve stimulation and stretching had significantly beneficial effects on muscle hardness, pressure pain threshold, and straight leg raising range of motion at T2, T3, and T4 compared with T1. [Conclusion] These results support the belief that transcutaneous electrical nerve stimulation combined with stretching is effective in reducing pain and decreasing muscle hardness, thus increasing range of motion.