The Effects of Dry Needling on Hamstring Range of Motion: A Critically Appraised Topic.

CLINICAL SCENARIO: Hamstring range of motion (ROM) and the influence it has on injury risk is among great discussion in the literature. Hamstring injury may result from hamstring tightness, poor flexibility, or decreased ROM, and many argue that this can be prevented through various intervention strategies. In active populations, risk of further injury, pain, and complications throughout the kinetic chain can occur if minimal hamstring ROM is left untreated. One therapeutic intervention that has been applied to varying parts of the body to help improve function while relieving pain is dry needling (DN). This intervention includes the application of needles to structures to induce responses that might benefit healing and overall stimulation of a neurological response. In this review, the intent is to identify evidence and the effects of DN on hamstring ROM. CLINICAL QUESTION: What are the effects of DN on hamstring ROM? SUMMARY OF KEY FINDINGS: Among total 11 articles, 1 single-blinded randomized controlled trial and 2 double-blinded randomized controlled trials were included in this critically appraised topic. All 3 articles had inconclusive evidence to isolate the application of the DN intervention. There was insufficient evidence to identify if DN independently improved hamstring ROM; however, in combination with interventions such as exercise and stretch plans, there were improvements on ROM. CLINICAL BOTTOM LINE: DN does not significantly increase or decrease the ROM of the hamstrings. When combined with exercise and stretch plans, DN could increase ROM. STRENGTH OF RECOMMENDATION: The grade of B is recommended by the Strength of Recommendation Taxonomy for inconsistent or limited-quality patient-oriented evidence.

Comparison of utilizing modified hold-relax, muscle energy technique, and instrument-assisted soft tissue mobilization on hamstring muscle length in healthy athletes: Randomized controlled trial.

INTRODUCTION: The hamstring muscle shortness is the primary risk factor for sports-related injuries. Numerous treatments are available for lengthening of hamstring muscle. The main purpose of this study was to compare the immediate effect of modified hold-relax, muscle energy technique (MET), and instrument assisted soft tissue mobilization-Graston techniques (IASTM-GT) on length of hamstring muscle in young healthy athletes. METHODS: 60 athletes comprising of 29 females and 31 males were recruited in the present study. Participants were allocated to 3 groups of IASTM-GT (N = 20, 13 male, 7 female), Modified Hold-relax (N = 20, 8 male, 12 female), and MET (N = 20, 7 male, 13 female). Active knee extension and passive straight leg raising (SLR), and toe touch test were performed before and immediately after the intervention by a blinded assessor. For the comparison of dependent variables across time, 3*2 repeated measure ANOVA was utilized. RESULTS: Interaction of group by time was significant for passive SLR (P < 0.001). Interaction of group by time was not significant for active knee extension (P = 0.17). The results showed that dependent variables increased significantly in all groups. The effect size (Cohen's d) in the groups of IASTM-GT, modified Hold-relax, and MET was 1.7, 3.17, and 3.12, respectively. CONCLUSION: Although the measures were improved in all groups, it seems that IASTM-GT can be used as a safe and efficient treatment, which can be a suitable candidate alongside modified hold-relax and MET for increasing the hamstrings muscle length in healthy athletes.

The immediate effects of foam rolling of the hamstrings muscle group on the contractile properties of the knee muscles in football players.

INTRODUCTION: Excessive amounts of intense training, without adequate recovery time, can overload the musculoskeletal, immune, and metabolic systems, resulting in a potentially negative effects on later exercise performance. During the competitive period, the ability to recover after intense training and competition is an important factor of success in soccer. The purpose of this study was to determine the effect of hamstring foam rolling on the knee muscle contractile properties in soccer players, after a sports-specific load. METHODS: 20 male professional soccer players were included and contractile properties of the biceps femoris, rectus femoris, vastus medialis and vastus lateralis muscles were measured with tensiomyography, before and after a Yo-Yo interval test and after 5 × 45 s of hamstring foam rolling. Additionally, active and passive knee extensibility before and after the intervention were measured. A mixed linear model was performed to determine the differences between the mean values of the groups. The experimental group performed foam rolling, while the control was resting. RESULTS: Five repetitions of 45 s of hamstring foam rolling had no statistically significant effect (p > 0.05) on any of the measured muscles following the Yo-Yo interval test or foam rolling intervention. There were no statistically significant differences in delay time, contraction time and maximum muscle amplitude between groups. Active and passive knee extensibility did not differ between groups. DISCUSSION AND CONCLUSION: It seems that foam rolling does not affect mechanical properties of the knee muscles or hamstring extensibility in soccer players, after a sports-specific load.

Hamstrings fascicle length and physical performance changes after a single bout of dynamic stretching or neurodynamic gliding in healthy young and older adults.

INTRODUCTION: The physiological and structural alterations have been less reported in response to dynamic stretching (DS) or neurodynamic nerve gliding (NG). Accordingly, this study investigated the changes in fascicle lengths (FL), popliteal artery velocity, and physical fitness in response to a single bout of DS or NG. METHODS: The study included 15 healthy young adults (20.9 ± 0.7 yrs) and 15 older adults (66.6 ± 4.2 yrs) who randomly performed three different interventions (DS, NG, and rest control) for 10 min and 3 days apart. The biceps femoris and semitendinosus FL, popliteal artery velocity, sit and reach (S&R), straight leg raise (SLR), and fast walking speed were measured before and immediately after the intervention. RESULTS: After NG intervention, S&R was largely greater by 2 cm (1.2, 2.8 cm) and 3.4 cm (2.1, 4.7 cm) with largely increased SLR angles of 4.9° (3.7°, 6.1°) and 4.6° (3.0°, 6.2°) with all p < 0.001 for the older adults and young groups, respectively. A similar magnitude improvement in the S&R and SLR testing was also seen for both groups after DS (p < 0.05). Moreover, no changes were seen in FL, popliteal artery velocity, fast gait speed, and age effect following all three intervention occasions. CONCLUSION: Stretching with DS or NG immediately increased flexibility, which appeared to be largely due to changes in stretch tolerance rather than an increase in fascicle length. Furthermore, age dependency in response to stretching exercise was not seen in the present study.

The Effect of Remote Myofascial Release on Chronic Nonspecific Low Back Pain With Hamstrings Tightness.

CONTEXT: Anatomy trains theory states that performing techniques in any part of the superficial myofascial backline can remotely treat other parts of this pathway. Due to the connections of different parts of the superficial backline, it is possible to influence the hamstring by performing the technique in the lumbar area. As chronic nonspecific low back pain (LBP) may lead to or be caused by hamstring tightness, remote myofascial release (MFR) techniques using the superficial backline can help improve hamstring tightness. OBJECTIVE: This study aimed to evaluate the effect of remote MFR on hamstring tightness for those with chronic nonspecific LBP. DESIGN: Single-blind, parallel design. SETTING: The present study was performed at the clinical setting of Tarbiat Modares University in Iran. METHODS: This study included 40 participants (20 males and 20 females) who were 40.5 (5.3) years old with chronic nonspecific LBP and hamstring tightness. INTERVENTIONS: Participants were randomly divided into the lumbar MFR (remote area) and hamstring MFR groups. Participants underwent 4 sessions of MFR for 2 weeks. MAIN OUTCOME MEASURES: A passive knee-extension (PKE) test was used for muscle tightness evaluation 3 times. RESULTS: Repeated-measure analysis of variance test showed that after the lumbar and hamstring MFR, the PKE was significantly reduced in both legs: lumbar MFR (right knee: from 61.04° [2.17°] to 51.01° [4.11°], P ≤ .003 and left knee: from 63.02° [3.12°] to 52.09° [2.48°], P ≤ .004) and hamstring MFR (right knee: from 62.01° [4.32°] to 50.50° [7.18°], P ≤ .001 and left knee: from 63.11° [2.56°] to 51.32° [5.31°], P ≤ .002). Least Significant Difference (LSD) post hoc test results showed that the 2 groups were not significantly different after the MFR (P ≥ .05). Also, the intraclass correlation coefficient index showed that the PKE test has excellent reliability (intraclass correlation coefficient, .910 for the right limb and .915 for the left limb). The minimal detectable change at the 95% confidence interval indicated that a change greater than or equal to 6° is required to exceed the threshold of the error PKE test, respectively. CONCLUSION: The present study showed that the remote MFR technique to the lumbar region demonstrated the same significant results in decreasing hamstring tightness as was noted in hamstring MFR to both limbs in patients with chronic nonspecific LBP.

Instrument-Assisted Soft Tissue Mobilization Increased Hamstring Mobility.

CONTEXT: Limited research reveals that the use of different soft tissue mobilization techniques increases tissue mobility in different regions of the body. OBJECTIVE: The purpose of this study was to determine whether there is a difference between administering instrument-assisted soft tissue mobilization (IASTM) and therapeutic cupping (TC) on hamstring tightness. DESIGN: Subjects attended one session wherein treatment and leg order were randomized before attending the session. A statistical analysis was completed using a 2 (intervention) × 2 (time) repeated-measures analysis of variance at α level ≤ .05. PARTICIPANTS: Thirty-three subjects between the age of 18-35 years old with bilateral hamstring tightness participated in this study. INTERVENTIONS: The IASTM and TC were administered on different legs for 5 minutes and over the entire area of the hamstring muscles. One TC was moved over the entire treatment area in a similar fashion as the IASTM. MAIN OUTCOME MEASURES: The intervention measurements included soreness numeric rating scale, Sit-n-Reach (single leg for side being tested), goniometric measurement for straight-leg hip-flexion motion, and superficial skin temperature. The timeline for data collection included: (1) intervention measurements for the first randomized leg, (2) 5-minute treatment with the first intervention treatment, (3) intervention measurements repeated for postintervention outcomes, and (4) repeat the same steps for 1 to 3 with the contralateral leg and the other intervention. RESULTS: There was a main effect over time for Sit-n-Reach, measurement (pre-IASTM-29.50 [8.54], post-IASTM-32.11 [8.31] and pre-TC-29.67 [8.21], post-TC-32.05 [8.25]) and goniometric measurement (pre-IASTM-83.45 [13.86], post-IASTM-92.73 [13.20] and pre-TC-83.76 [11.97], post-TC-93.67 [12.15]; P < .05). CONCLUSION: Both IASTM and TC impacted hamstring mobility during a single treatment using only an instrument-assisted soft tissue mobilization technique without any additional therapeutic intervention.

Comparison of A Single Vibration Foam Rolling and Static Stretching Exercise on the Muscle Function and Mechanical Properties of the Hamstring Muscles.

Knee extension and hip flexion range of motion (ROM) and functional performance of the hamstrings are of great importance in many sports. The aim of this study was to investigate if static stretching (SS) or vibration foam rolling (VFR) induce greater changes in ROM, functional performance, and stiffness of the hamstring muscles. Twenty-five male volunteers were tested on two appointments and were randomly assigned either to a 2 min bout of SS or VFR. ROM, counter movement jump (CMJ) height, maximum voluntary isometric contraction (MVIC) peak torque, passive resistive torque (PRT), and shear modulus of semitendinosus (ST), semimembranosus (SM), and biceps femoris (BFlh), were assessed before and after the intervention. In both groups ROM increased (SS = 7.7%, P < 0.01; VFR = 8.8%, P < 0.01). The MVIC values decreased after SS (-5.1%, P < 0.01) only. Shear modulus of the ST changed for -6.7% in both groups (VFR: P < 0.01; SS: P < 0.01). Shear modulus decreased in SM after VFR (-6.5%; P = 0.03) and no changes were observed in the BFlh in any group (VFR = -1%; SS = -2.9%). PRT and CMJ values did not change following any interventions. Our findings suggest that VFR might be a favorable warm-up routine if the goal is to acutely increase ROM without compromising functional performance.

The acute effects of different hamstring muscle stretching techniques on reducing muscle resistance to movement by ultrasound elastography.

OBJECTIVE: Many stretching methods are applied on the hamstring muscles for reducing muscle resistance on movement. The aim of our study to investigate the acute effects of static stretching and the Mulligan traction straight leg raise (TSLR) technique administered to the hamstring muscles on reducing its resistance to movement. METHODS: The study included 22 healthy male volunteers (19.5 ± 0.98 years). After the individuals were randomly divided into two groups, static stretching was administered to the hamstring muscles in the first group and the Mulligan TSLR technique was administered on the same muscle in the second group. Active knee extension angles of the individuals were evaluated by a digital goniometer and muscle strain was assessed by ultrasound elastography. RESULTS: While there was a significant difference in all parameters in both groups after the treatment, the changes in the active knee extension angle and the strain index value of the biceps femoris musculotendinous junction were higher in the Mulligan TSLR group compared to the static stretching group (p < 0.05). CONCLUSION: It was concluded that, static stretching and the Mulligan TSLR technique administered to the hamstring muscles are effective ways to increase the range of motion. The Mulligan TSLR technique, however, can be opted in healthy individuals and patients since it is painless and more effective in reducing muscle resistance to movement and range of motion.

The Effects of a Self-Myofascial Release Program on Isokinetic Hamstrings-to-Quadriceps Strength Ratio and Range of Motion of the Knee Joint Among Athletes With Hamstring Shortness.

CONTEXT: Range of motion (ROM) and muscular strength are the main factors that affect athletic performance. Self-myofascial release is a flexibility technique, which is used to inhibit overactive muscle fibers. OBJECTIVE: To investigate the effects of the 8-week self-myofascial release on the isokinetic hamstrings-to-quadriceps strength ratio (H/QRatio) and the ROM of the knee joint among male athletes with the hamstring shortness. DESIGN: A randomized controlled trial. SETTING: Research laboratory. PARTICIPANTS: Twenty-four college-aged male athletes with hamstring shortness were selected for this study and were randomly assigned to a foam rolling group (FOAM, n = 12) and a control group (n = 12). INTERVENTIONS: Participants in the FOAM group performed supervised self-myofascial release program 3 times per week for 8 weeks. The control group received no intervention. METHODS: Data were analyzed via 2-way repeated-measure analysis of variance at the significance level of .05. MAIN OUTCOME MEASURES: ROM and the H/QRatio at the velocities of 60°/s, 120°/s, and 180°/s were measured by an isokinetic dynamometer. RESULTS: The results of 2-way repeated-measure analysis of variance demonstrated that hamstring ROM increased in FOAM group (P = .001). No significant changes were found in H/QRatio after self-myofascial release for FOAM group (P ≥ .05). CONCLUSIONS: When compared with other methods of stretching, self-myofascial release with foam rolling may be beneficial in increasing ROM without decreasing H/QRatio in people with the hamstring shortness.

Sonographic measures and sensory threshold of the normal sciatic nerve and hamstring muscles.

PURPOSE: The sciatic nerve innervates the hamstring muscles. Occasionally, the sciatic nerve is injured along with a hamstring muscle. Detailed biomechanical and sensory thresholds of these structures are not well-characterized. Therefore, we designed a prospective study that explored high-resolution ultrasound (US) at multiple sites to evaluate properties of the sciatic nerve, including cross-sectional area (CSA) and shear-wave elastography (SWE). We also assessed SWE of each hamstring muscle at multiple sites. Mechanical algometry was obtained from the sciatic nerve and hamstring muscles to assess multi-site pressure pain threshold (PPT). METHODS: Seventy-nine asymptomatic sciatic nerves and 147 hamstring muscles (25 males, 24 females) aged 18-50 years were evaluated. One chiropractic radiologist with 4.5 years of US experience performed the evaluations. Sciatic nerves were sampled along the posterior thigh at four sites obtaining CSA, SWE, and algometry. All three hamstring muscles were sampled at two sites utilizing SWE and algometry. Descriptive statistics, two-way ANOVA, and rater reliability were assessed for data analysis with p ≤ 0.05. RESULTS: A significant decrease in sciatic CSA from proximal to distal was correlated with increasing BMI (p < 0.001). Intra-rater and inter-rater reliability for CSA was moderate and poor, respectively. Elastographic values significantly increased from proximal to distal with significant differences in gender and BMI (p = 0.002). Sciatic PPT significantly decreased between sites 1 and 2, 1 and 3, and 1 and 4. Significant correlation between gender and PPT was noted as well as BMI (p < 0.001). Hamstring muscle elastographic values significantly differed between biceps femoris and semitendinosus (p < 0.001) and biceps femoris and semimembranosus (p < 0.001). All three hamstring muscles demonstrated increased PPT in males compared to females (p < 0.001). In addition, PPT of the biceps femoris correlated with BMI (p = 0.02). CONCLUSION: High-resolution US provided useful metrics of sciatic nerve size and biomechanical properties. PPT for the normal sciatic nerve and hamstring muscles was obtained for future clinical application.

Differences in Pivot Leg Kinematics and Electromyography Activation in Various Round House Kicking Heights.

The round house kick (RHK) is a common technique in taekwondo (TKD). The kicking action originates from the dynamic stability of the pivot leg. However, some knee injuries are caused by more difficult kicking strategies, such as kicks to the opponent's head. This study analyses the effects on TKD players in the lower extremity kinematic and neuromuscular reactions from different kicking heights. This study recruited 12 TKD players (age=20.3 ± 1.3 years, height = 1.72 ± 0.09 m, mass = 62.17 ± 9.45 kg) with no previous lower extremity ligament injuries. All athletes randomly performed 3 RHK at different heights (head, chest, and abdomen), repeating each kick 5 times. During the RHK action, the kinematics and muscle activations of the pivot leg were collected using six high-speed cameras and electromyography devices. The results found that during the RHK return period a high kicking position demonstrated larger knee valgus with the straight knee, and more hamstring activation on the pivot leg. The RHK pivot foot for TKD players encountered more risk of injury from high target kicking. The hamstring muscle played an important stabilizing role. It is recommended that sports medicine clinicians or sports coaches use this information to provide further protective injury prevention strategies.

Evidence for Subcortical Plasticity after Paired Stimulation from a Wearable Device.

Existing non-invasive stimulation protocols can generate plasticity in the motor cortex and its corticospinal projections; techniques for inducing plasticity in subcortical circuits and alternative descending pathways such as the reticulospinal tract (RST) are less well developed. One possible approach developed by this laboratory pairs electrical muscle stimulation with auditory clicks, using a wearable device to deliver stimuli during normal daily activities. In this study, we applied a variety of electrophysiological assessments to male and female healthy human volunteers during a morning and evening laboratory visit. In the intervening time (∼6 h), subjects wore the stimulation device, receiving three different protocols, in which clicks and stimulation of the biceps muscle were paired at either low or high rate, or delivered at random. Paired stimulation: (1) increased the extent of reaction time shortening by a loud sound (the StartReact effect); (2) decreased the suppression of responses to transcranial magnetic brain stimulation (TMS) following a loud sound; (3) enhanced muscle responses elicited by a TMS coil oriented to induce anterior-posterior (AP) current, but not posterior-anterior (PA) current, in the brain. These measurements have all been suggested to be sensitive to subcortical, possibly reticulospinal, activity. Changes were similar for either of the two paired stimulus rates tested, but absent after unpaired (control) stimulation. Taken together, these results suggest that pairing clicks and muscle stimulation for long periods does indeed induce plasticity in subcortical systems such as the RST.SIGNIFICANCE STATEMENT Subcortical systems such as the reticulospinal tract (RST) are important motor pathways, which can make a significant contribution to functional recovery after cortical damage such as stroke. Here, we measure changes produced after a novel non-invasive stimulation protocol, which uses a wearable device to stimulate for extended periods. We observed changes in electrophysiological measurements consistent with the induction of subcortical plasticity. This protocol may prove an important tool for enhancing motor rehabilitation, in situations where insufficient cortical tissue survives to be a plausible substrate for recovery of function.

Crossover effects of ultrasound-guided percutaneous neuromodulation on contralateral hamstring flexibility.

BACKGROUND: Crossover effects refer to the responses of a non-exercised contralateral limb. There is evidence of this effect, as it relates to muscle fatigue, strength, and stretch, but not as it relates to neuromodulation. OBJECTIVES: To compare the crossover effects of percutaneous neuromodulation (PNM) on hip range of motion (ROM), observed in a straight leg raise (SLR) test, in asymptomatic participants with bilateral reduced hamstring flexibility, versus the neurodynamic sciatic sliding technique, hamstring stretching and mechanical stimulation of the sciatic nerve using a needle (without electrical stimulation). To evaluate the tensiomyographic changes between the two lower limbs after these interventions. METHODS: 80 participants with bilateral reduced hamstring flexibility were randomized into four groups: Stretching, Neurodynamic, PNM, and Needle groups. All interventions were performed on the right limb. Each participant's leg was subjected to SLR testing and tensiomyography before and after the interventions. RESULTS: Each group improved their SLR values in the non-intervention limb compared to baseline values, but the PNM and Needle groups obtained higher values for the SLR test in the non-intervention limb compared with the Neurodynamic and Stretching groups. There were statistically significant differences for mean SLR measures between limbs pre- and post-intervention for all groups except the PNM group, suggesting crossover effects for PNM but not the other techniques studied. There were no differences in tensiomyographic assessments between groups or between sides, at baseline or upon completion of the study. CONCLUSION: PNM produced benefits in the SLR test in the non-intervention limb and only 1.5 min was enough to obtain this effect. In addition, no technique interfered with muscle activation.

Influence of Lumbar Mobilizations During the Nordic Hamstring Exercise on Hamstring Measures of Knee Flexor Strength, Failure Point, and Muscle Activity: A Randomized Crossover Trial.

OBJECTIVE: The aims of this study were to quantify the effects of spinal mobilization on force production, failure point, and muscle activity of the hamstrings during the Nordic hamstring exercise (NHE), and to explore individual differences in responses. METHODS: In a replicated randomized crossover trial, 24 asymptomatic, recreationally active men (age [mean ± standard deviation]: 27 ± 6 years; body mass: 82 ± 17 kg; height: 181 ± 8 cm) completed 2 standardized intervention trials (L4/5 zygapophyseal mobilizations) and 2 control trials. The failure point of the NHE was determined with 3D motion capture. Peak force, knee flexor torque, and electromyography (EMG) of the biceps femoris were measured. Data analyses were undertaken to quantify mean intervention response and explore any individual response heterogeneity. RESULTS: Mean (95% confidence interval) left-limb force was higher in intervention than in control trials by 18.7 (4.6-32) N. Similarly, right-limb force was higher by 22.0 (3.4-40.6) N, left peak torque by 0.14 (0.06-0.22) N • m, and right peak torque by 0.14 (0.05-0.23) N • m/kg. Downward force angle was decreased in intervention vs control trials by 4.1° (0.5°-7.6°) on the side of application. Both peak EMG activity (P = .002), and EMG at the downward force (right; P = .020) increased in the intervention condition by 16.8 (7.1-26.4) and 8.8 (1.5-16.1) mV, respectively. Mean downward acceleration angle changed by only 0.3° (-8.9° to 9.4°) in intervention vs control trials. A clear response heterogeneity was indicated only for right force (Participant × Intervention interaction: P = .044; response heterogeneity standard deviation = 34.5 [5.7-48.4] N). Individual response heterogeneity was small for all other outcomes. CONCLUSION: After spinal mobilization, immediate changes in bilateral hamstring force production and peak torque occurred during the NHE. The effect on the NHE failure point was unclear. Electromyographic activity increased on the ipsilateral side. Response heterogeneity was generally similar to the random trial-to-trial variability inherent in the measurement of the outcomes.

Dry Needling for Hamstring Flexibility: A Single-Blind Randomized Controlled Trial.

CONTEXT: Hamstring muscle tightness is one of the most common problems in athletic and healthy people. Dry needling (DN) was found to be an effective approach for improving muscle flexibility, but there is no study to compare this approach with static stretching (SS) as a common technique for the increase of muscle length. OBJECTIVE: To compare the immediate effects of DN and SS on hamstring flexibility in healthy subjects with hamstring tightness. STUDY DESIGN: A single-blind randomized controlled trial. SETTING: A musculoskeletal physiotherapy clinic at Tehran University of Medical Sciences. SUBJECTS: Forty healthy subjects (female: 32, age range: 18-40 y) with hamstring tightness were randomly assigned into 2 groups of DN and SS. INTERVENTION: The DN group received a single session of DN on 3 points of the hamstring muscles, each for 1 minute. The SS group received a single session of SS of the hamstrings, consisting of 3 sets of 30-second SS with a 10-second rest between sets in the active knee extension test (AKET) position. MAIN OUTCOME MEASURES: The AKET, muscle compliance, passive peak torque, and stretch tolerance were measured at the baseline, immediately, and 15 minutes after the interventions. RESULTS: Improvements in all outcomes was better for the DN group than for the SS group. DN increased muscle compliance significantly 15 minutes after the intervention, but it did not improve in the SS group. CONCLUSION: DN is effective in improving hamstring flexibility compared with SS. One session of DN can be an effective treatment for hamstring tightness and increase hamstring flexibility. The improvements suggest that DN is a novel treatment for hamstring flexibility.

The immediate effect of IASTM vs. Vibration vs. Light Hand Massage on knee angle repositioning accuracy and hamstrings flexibility: A pilot study.

INTRODUCTION: The effectiveness of novel soft-tissue interventions relative to traditional ones requires further exploration. The purpose of this pilot study was to evaluate the immediate effect of Instrument Assisted Soft Tissue Mobilization (IASTM) compared to Vibration Massage or Light Hand Massage on hamstrings' flexibility and knee proprioception. METHODS: 16 healthy non-injured male participants (mean age 23.7 years, height 1.80 cms and body mass 77.7 kg) were randomly assigned to the following interventions: (a) 5min IASTM, (b) 5min Vibration Massage and (c) 8min Light Hand-Massage, sequentially delivered to all participants with an in-between 1-week time interval. A single application of each intervention was given over the hamstrings of their dominant leg (repeated measures under 3 different experimental conditions). An active knee angle reproduction proprioception test and the back-saver sit and reach flexibility test were performed before and immediately after each intervention. Reliability of outcomes was also assessed. RESULTS: Reliability for flexibility (ICC3,1 = 0.97-0.99/SEM = 0.83-1.52 cm) and proprioception (ICC3,1 = 0.83-0.88/SEM = 1.63-2.02°) was very good. For flexibility, statistically significant immediate improvement (p < 0.001) was noted in all 3 groups (1.61-3.23 cm), with no between-group differences. For proprioception, improvement in the IASTM (2.12°), Vibration Massage (0.32°) and Light Hand-Massage (1.17°) conditions was not statistically significant; no between-group differences were also evident. CONCLUSIONS: Our findings indicate that muscle flexibility was positively influenced immediately after a single intervention of IASTM, Vibration Massage or Light Hand Massage. Proprioception changes were not statistically significant either within or between groups. Further evaluation of those interventions in a larger population with hamstrings pathology is required.

Botulinum Toxin Type A Injections Impact Hamstring Muscles and Gait Parameters in Children with Flexed Knee Gait.

The aim of this study was to determine if botulinum toxin type A (BoNT-A) injection into the medial hamstring can improve gait kinematics and muscle-tendon length in spastic cerebral palsy (CP) with a flexed knee gait (FKG). Twenty-nine children with spastic CP (Gross Motor Function Classification System I-III) with FKG were recruited for this prospective study. BoNT-A was injected into the semitendinosus and semimembranosus (SM) muscles under ultrasonography guidance. Assessments included Gross Motor Function Measure (GMFM), Modified Ashworth Scale (MAS), Modified Tardieu Scale (MTS), 3-dimensional computerized gait analysis, calculated SM muscle-tendon length and lengthening velocity during gait using musculoskeletal modeling at baseline, 4 and 16 weeks after the injection. Compared to baseline data, significant improvements in GMFM, MAS, and MTS were demonstrated at weeks 4 and 16, and also a significant increase in maximum knee extension during the stance phase was observed at week 4. In addition, the mean lengthening velocity during the swing phase was increased at week 16 without a change in the SM muscle length. Furthermore, there was a significant increase in anterior pelvic tilt at week 4, compared to baseline data. The significant decrease in hip internal rotation after injection was observed only in children with excessive hip internal rotation at initial contact before injection. BoNT-A injection into hamstrings leads to a significant increase in knee extension and anterior pelvic tilt with an increase in lengthening velocity of SM in spastic CP with FKG.

Effects of a Multi-ingredient Beverage on Recovery of Contractile Properties, Performance, and Muscle Soreness After Hard Resistance Training Sessions.

Naclerio, F, Larumbe-Zabala, E, Cooper, K, and Seijo, M. Effects of a multi-ingredient beverage on recovery of contractile properties, performance, and muscle soreness after hard resistance training sessions. J Strength Cond Res 34(7): 1884-1893, 2020-Carbohydrate-protein-based supplements have been proposed for maximizing postexercise recovery. This study compared the effects of postworkout supplementation ingesting a multi-ingredient (MTN) vs. carbohydrate alone (CHO) on the recovery of muscle function and perceived of delayed onset of muscle soreness (DOMS) after hard resistance workouts. In a double-blinded, crossover design, 10 resistance trained men (26.9 ± 7.4 years) performed 2 identical 5-day intervention periods while ingesting either MTN or CHO. The subjects performed one workout per day during the first 3 days. Thereafter, they were assessed 1, 24, and 48 hours after the completion of the third workout session. Primary outcome was tensiomyography (muscle displacement [Dm], contraction time [Tc], and contraction velocity [Vc]) of the vastus medialis (VM) and biceps femoris long head (BFLH). Secondary outcomes were performance and DOMS. At 24 hours, both conditions decreased (p < 0.05) Dm (MTN -1.71 ± 1.8, CHO -1.58 ± 1.46 mm) and Vc (MTN -0.03 ± 0.03, CHO 0.03 ± 0.04 m·s) in the VM. At 48 hours, all tensiomyography variables were recovered under the MTN while remained depressed (p < 0.01) in CHO (VM, Dm 1.61 ± 1.60, Vc -0.04 ± 0.04 m·s; BFLH, Dm 1.54 ± 1.52, Vc -0.02 ± 0.02 m·s). Vertical jump performance decreased in CHO, but not in MTN. Although both conditions decreased upper-body strength and power at 1 hour, values returned to baseline in 24 hours for MTM while needed 48 hours in CHO. DOMS similarly increased at both 24 and 48 hours in both conditions. Compared with the ingestion of only carbohydrates, postworkout multi-ingredient supplementation seems to hasten recovery of muscular contractile properties and performance without attenuating DOMS after hard resistance workouts.

Moderate volume of sprint bouts does not induce muscle damage in well-trained athletes.

INTRODUCTION: Understanding the recovery in response to different sprint protocols is important for optimizing neuromuscular gains and organizing training sessions in sports. The current study aimed to investigate acute neuromuscular changes following a moderate volume of sprint protocols with and without change-of-direction. METHODS: 26 well-trained male collegiate athletes from different sports were randomly allocated into straight-line group (SLG) or change-of-direction group (CODG). The protocols were 1 × 15 repetitions of 20-meter sprints in line (SLG) or with two changes in each repetition (CODG). Knee extension maximal and explosive strength, jump performance, serum creatine kinase, and quadriceps and hamstrings echo intensity were collected pre-, post- 0, 24, 48, and 72 h post-exercise. RESULTS: There were no significant changes in any of the variables at any time point after the exercise protocols in comparison with pre-exercise values (p > 0.05). CONCLUSIONS: The present study suggests that sprint training with moderate volume with or without change of direction does not induce neuromuscular or physiological changes during 72 h post-exercise. This information is especially important for sports staff in order to optimize training prescription and frequency.

Self-Myofascial Release of the Superficial Back Line Improves Sit-and-Reach Distance.

CONTEXT: Decreased hamstring flexibility can lead to a plethora of musculoskeletal injuries, including low back pain, hamstring strains, and patellofemoral pain. Lack of flexibility may be the result of myofascial adhesions. The fascia connected to the hamstrings is part of the superficial back line that runs from the cranium to the plantar aspect of the foot. Any disruption along this chain may limit the flexibility of the hamstring. OBJECTIVE: To investigate if self-myofascial release (SMR) of the plantar surface of the foot in addition to the hamstring group was more effective at improving the flexibility of the hamstrings when compared with either intervention alone. DESIGN: Cross-over study. SETTING: Athletic training facility. PARTICIPANTS: Fifteen college students (5 males and 10 females; age: 20.9 [1.4] y, height: 173.1 [10.3] cm, mass: 80.0 [24.9] kg) who were not older than 30, with no history of low back pain or injury within the past 6 months, no history of leg pain or injury within the past 6 months, no current signs or symptoms of cervical or lumbar radicular pain, no current complaint of numbness or tingling in the lower-extremity, and no history of surgery in the lower-extremity or legs. INTERVENTIONS: Each participant received each intervention separated by at least 96 hours in a randomized order: hamstring foam rolling, lacrosse ball on the plantar surface of the foot, and a combination of both. MAIN OUTCOME MEASURES: The sit-and-reach test evaluated hamstring flexibility of each participant before and immediately after each intervention. RESULTS: There were no significant differences found among the SMR techniques on sit-and-reach distance (F2,41 = 2.7, P = .08, ηp2=.12). However, at least 20% of participants in each intervention improved sit-and-reach distance by 2.5 cm. CONCLUSIONS: SMR may improve sit-and-reach distance, but one technique of SMR does not seem to be superior to another.