Is muscle stiffness a determinant for range of motion in the leg muscles?

Previous training studies with comprehensive stretching durations have reported that an increase in range of motion (ROM) can be related to decreases in muscle stiffness. Therefore, the purpose of this study was to analyze the association between the passive muscle stiffness of three muscle groups (triceps surae, quadriceps, hamstrings) to the respective joint ROM. Thirty-six healthy male soccer players volunteered in this study. After a standardized warm-up, the muscle stiffness was tested via shear wave elastography in six muscles (gastrocnemius medialis and lateralis, rectus femoris, semitendinosus, semimembranosus, and biceps femoris long head). The hip extension, hip flexion, and ankle dorsiflexion ROM were also assessed with a modified Thomas test, a sit and reach test, and a standing wall push test, respectively. We found significant moderate to large correlations between hip flexion ROM and muscle stiffness for the semimembranosus (rP = -0.43; P = 0.01), biceps femoris long head (rP = -0.45; P = 0.01), and overall hamstring stiffness (rP = -0.50; P < 0.01). No significant correlations were found for triceps surae (rP = -0.12; P = 0.51 to 0.67) and rectus femoris muscle stiffness (rP = 0.25; P = 0.14) with ankle dorsiflexion and hip extension ROM, respectively. We conclude that muscle stiffness is an important contributor to hip flexion ROM, but less important for hip extension or ankle joint ROM. Additional contributors to ROM might be tendon stiffness or stretch/pain tolerance.

Remote effects of a 7-week combined stretching and foam rolling training intervention of the plantar foot sole on the function and structure of the triceps surae.

It is known that a single bout of foam rolling (FR) or stretching can induce changes in range of motion (ROM) and performance in non-directly adjoining areas of the dorsal chain (i.e., remote effects). However, to date, it is not known if such effects exist following long-term interventions. Thus, the purpose of this study was to investigate the remote effects of a 7-week combined stretching and FR training intervention of the plantar foot sole. Thirty-eight recreational athletes were randomly assigned to either an intervention (n = 20) or control (n = 18) group. The intervention group performed stretching and FR exercises of the plantar foot sole for 7 weeks. Before and after the intervention, the dorsiflexion ankle ROM, passive resistive torque at maximum angle (PRTmax) and at a fixed angle, as well as maximum voluntary isometric contraction (MVIC) torque, were measured with a dynamometer. Gastrocnemius medialis and lateralis stiffness was assessed with shear wave elastography. The results showed no interaction effect for any of the parameters. There was a time effect indicating an increase in MVIC and PRTmax, which was more pronounced in the intervention group (+ 7.4 (95% CI 2.5-12.4), + 4.5 (95% CI - 0.2-9.2)) than the control group (+ 3.6 (95% CI - 1.4-8.6), + 4.0 (95% CI - 2.2 to 10.2)). The results indicate no or minor remote effects of combined stretching and FR of the foot sole in the ankle joint. Potential non-significant changes in ROM were accompanied with an increase in stretch tolerance, but not with changes in muscle structure.

The Acute Effects of Pectoralis Major Foam Ball Rolling on Shoulder Extension Range of Motion, Isometric Contraction Torque, and Muscle Stiffness.

Although it is well known that foam rolling (FR) of the lower extremities can increase the range of motion (ROM) of a joint while likely having no detrimental effect on muscle performance, to date, this is not clear if this is the case for the upper body. Therefore, the purpose of this study was to analyze the effects of a 2-min FR intervention of the pectoralis major (PMa) muscle on muscle stiffness of the PMa, shoulder extension ROM, and maximal voluntary isometric contraction (MVIC) peak torque. Thirty-eight (n = 15 females) healthy, physically active participants were randomly assigned to either an intervention (n = 18) or a control group (n = 20). The intervention group performed a 2-min foam ball rolling (FBR) intervention of the PMa muscle (FB-PMa-rolling), while the control group rested for 2 min. Before and after the intervention, muscle stiffness of the PMa was measured with shear wave elastography, while shoulder extension ROM was recorded with a 3D-motion capture system, and shoulder flexion MVIC peak torque was measured with a force sensor. MVIC peak torque decreased in both groups (time effect: p = 0.01; η2 = 0.16), without any difference between groups (interaction effect: p = 0.49, η2 = 0.013). ROM (p = 0.24; η2 = 0.04) and muscle stiffness (FB-PMa-rolling p = 0.86; Z = -0.38; control group p = 0.7, Z = -0.17) did not change due to the intervention. The lack of changes in ROM and muscle stiffness following the FBR intervention might be explained by the small area of applied pressure with the FBR on the PMa muscle. Moreover, the decrease in MVIC peak torque is likely more related to the uncommon test situation of the upper limbs, rather than the FBR intervention itself.

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.

An Intense Warm-Up Does Not Potentiate Performance Before or After a Single Bout of Foam Rolling.

Foam rolling (FR) is a common intervention used as a warm-up to increase the range of motion (ROM) of a joint, without changes in subsequent performance. It has been shown that, in similar techniques (e.g., stretching), an additional intense warm-up can lead to performance potentiation. However, to date, it is not clear if this also holds true for FR, and if this effect is similar in both sexes. Thus, the purpose of this study was to compare the effects of an intense warm-up either before or after FR with the effects of FR without any additional intense warm-up, in both females and males. In total, 27 volunteers (14 male, 13 female) visited the laboratory on three separate days. Each participant was randomly assigned to one of the three interventions. ROM was assessed with a Sit n' Reach box, and countermovement jump (CMJ) height with a force plate, both before and after the interventions. In addition, maximum voluntary isometric contraction (MVIC) peak torque and maximum voluntary dynamic contraction (MVDC) peak torque were assessed with a dynamometer. ROM increased to the same extent following the interventions in all groups, with a large magnitude of change (P < 0.001; d = 1.12 to 1.83). In addition, male participants showed significantly higher increases in ROM when the intense warm-up was performed after FR (P < 0.001; d = 1.44), but not without the intense warm-up (P = 0.45; d = 0.57) or when the intense warm-up was performed before FR (P = 0.24; d = 0.69). No significant changes in CMJ height, MVIC peak torque, or MVDC peak torque were observed (P > 0.05). We therefore conclude that the time-efficient athlete might skip further intense warm-up, besides FR, when the goal is to increase ROM and to sustain performance parameters.

A comparison of foam rolling and vibration foam rolling on the quadriceps muscle function and mechanical properties.

PURPOSE: The purpose of the study was to investigate the effects of using a vibration foam roll (VFR) or a non-vibration foam roll (NVFR) on maximum voluntary isometric contraction peak torque (MVIC), range of motion (ROM), passive resistive torque (PRT), and shear modulus. METHODS: Twenty-one male volunteers visited the laboratory on two separate days and were randomly assigned to either a VFR group or a NVFR group. Both interventions were performed for 3 × 1 min each. Before and after each intervention, passive resistive torque and maximum voluntary isometric contraction peak torque of the leg extensors were assessed with a dynamometer. Hip extension ROM was assessed using a modified Thomas test with 3D-motion caption. Muscle shear modulus of the vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) was assessed with shear wave elastography (SWE). RESULTS: In both groups (VFR, NVFR) we observed an increase in MVIC peak torque (+ 14.2 Nm, + 8.6 Nm) and a decrease in shear modulus of the RF (- 7.2 kPa, - 4.7 kPa). However, an increase in hip extension ROM (3.3°) was only observed in the VFR group. There was no change in PRT and shear modulus of the VL and VM, in both the VFR group and the NVFR group. Our findings demonstrate a muscle-specific acute decrease in passive RF stiffness after VFR and NVFR, with an effect on joint flexibility found only after VFR. CONCLUSION: The findings of this study suggest that VFR might be a more efficient approach to maximize performance in sports with flexibility demands.

The Acute Effects of a Percussive Massage Treatment with a Hypervolt Device on Plantar Flexor Muscles' Range of Motion and Performance.

Handheld percussive massage treatment has gained popularity in recent years, for both therapeutic use and in sports practice. It is used with the goals of increasing flexibility and performance, but also to accelerate recovery. However, until now, there has been no scientific evidence, which proves such effects. Therefore, the purpose of this study was to investigate the effects of a 5-min percussion treatment of the calf muscles on range of motion (ROM) and maximum voluntary contraction (MVC) torque of the plantar flexor muscles. Sixteen healthy male volunteers (mean ± SD; 27.2 ± 4.2 years, 1.79 ± 0.05 m, 79.4 ± 9.1 kg) were tested on two separate days with either a 5-min massage treatment of the calf muscles with a Hypervolt device or the control condition (sitting only). Before and after the treatments, dorsiflexion ROM and MVC torque of the plantar flexor muscles were measured with a dynamometer. Maximum dorsiflexion ROM increased with a large magnitude following the massage treatment by 5.4° (+18.4%; p = 0.002, d= 1.36), while there was no change in the control group. Moreover, MVC torque did not change following both the massage treatment and the control treatment. Similar to a conventional massage by a therapist, ROM can be increased by a handheld percussive massage treatment without having an effect on muscle strength.

Relationship between pectoralis major stiffness and shoulder extension range of motion.

This study aimed to investigate the correlation between the passive muscle stiffness of the pectoralis major muscle pars clavicularis (PMc) and shoulder extension range of motion (ROM) in both male and female participants. Thirty-nine (23 male/16 female) physically active and healthy participants volunteered in this study. After a standardized warm-up, the PMc stiffness was tested via shear wave elastography at a slightly stretched position (long muscle length) and in a non-stretched position (short muscle length). Additionally, a custom-made device and 3D motion capture assessed the active shoulder extension ROM. We found a significant moderate and negative relationship between shoulder extension ROM and PMc stiffness at long muscle length (rs = -0.33; p = 0.04) but not at short muscle length (r = -0.23; p = 0.17). Additionally, there was no significant difference between male and female participants in the correlation analyses at both elbow angles. The moderate correlation between PMc stiffness at a slightly stretched position and shoulder extension ROM suggests that additionally, other structures such as nerves/fascia stiffness or even stretch tolerance might be factors that can be related to shoulder extension ROM.

Effects of a High-Volume 7-Week Pectoralis Muscle Stretching Training on Muscle Function and Muscle Stiffness.

BACKGROUND: There is evidence that high-volume static stretching training of the lower limbs can increase the range of motion (ROM) while decreasing muscles stiffness. However, to date, there is no evidence on the effects of upper limb stretching training or its effect mechanism. Therefore, this study aimed to investigate the effects of a comprehensive 7-week static stretching training program of the pectoralis major muscle (PMa) on glenohumeral joint ROM, muscle force, and muscle stiffness. METHODS: Thirty-eight healthy, physically active participants (23 male, 15 female) were randomly assigned to either the PMa-static stretching intervention (PMa-SS) group or the control group. The PMa-SS group performed a 7-week intervention comprising three sessions a week for 15 min per session, including three static stretching exercises of the PMa for 5 min each. Before and after the intervention period, shoulder extension ROM, muscle stiffness of the PMa (pars clavicularis), and maximal voluntary isometric contraction (MVIC) peak torque (evaluated at both long (MVIClong) and short (MVICshort) muscle lengths) were investigated on a custom-made testing device at 45° shoulder abduction. RESULTS: In the PMa-SS group, the shoulder extension ROM (+ 6%; p < 0.01; d = 0.92) and the MVIClong (+ 11%; p = 0.01; d = 0.76) increased. However, there were no significant changes in MVICshort or in PMa muscle stiffness in the PMa-SS group. In the control group, no changes occurred in any parameter. CONCLUSION: In addition to the increase in ROM, we also observed an improved MVIC at longer but not shorter muscle lengths. This potentially indicates an increase in fascicle length, and hence a likely increase in sarcomeres in series.

The non-local effects of 7-week foot sole static stretching and foam rolling training on shoulder extension range of motion.

Static stretching and foam rolling can increase the range of motion (ROM) of a joint acutely as well as chronically. Although studies have reported ROM increases of a non-stretched heterologous muscle (non-local) following an acute static stretching or foam rolling session, these effects have not been studied for long-term training interventions. Therefore, the purpose of this study was to investigate the effects of a comprehensive 7-week static stretching and foam rolling training program of the foot sole on shoulder extension ROM. A total of 33 healthy, physically active participants (20 male) were assigned to either the intervention (n = 19) or control (n = 14) group. The intervention group performed a 7-week combined static stretching and foam rolling intervention comprising three sessions a week, including three exercises of the foot sole for 5 min each. Before and after the intervention period, the shoulder extension ROM was tested with three-dimensional (3D) motion caption. The level of significance for all statistical analyses was set to ρ ≤ 0.05. There was no significant time (p = 0.70, F1, 31 = 0.157; η2 = 0.005) or time×group effect (p = 0.38, F1, 31 = 0.785; η2 = 0.025) in shoulder extension ROM, indicating no ROM changes in the intervention or the control group. Although previous studies on the acute effects of stretching and foam rolling reported non-local increases in ROM in heterologous muscles, this study could show that such effects do not occur after chronic SS and foam rolling training for 7 weeks. Consequently, if the goal is to chronically increase the ROM of a specific joint, it is recommended to directly treat the muscles of interest.

Effects of a Single Proprioceptive Neuromuscular Facilitation Stretching Exercise With and Without Post-stretching Activation on the Muscle Function and Mechanical Properties of the Plantar Flexor Muscles.

A single proprioceptive neuromuscular facilitation (PNF) stretching exercise can increase the range of motion (ROM) of a joint but can lead to a decrease in performance immediately after the stretching exercise. Post-stretching activation (PSA) exercises are known as a possible way to counteract such a drop in performance following a single stretching exercise. However, to date, no study has investigated the combination of PNF stretching with PSA. Thus, the aim of this study was to compare the effects of a PNF stretching exercise with and without PSA on the muscle function (e.g., ROM) and mechanical properties of the plantar flexor muscles. Eighteen physically active males volunteered in the study, which had a crossover design and a random order. The passive shear modulus of the gastrocnemius medialis (GM) and gastrocnemius lateralis (GL) was measured in a neutral position with shear wave elastography, both pre- and post-intervention. Maximum voluntary isometric contraction (MVIC) peak torque, maximum voluntary dynamic contraction peak torque, dorsiflexion ROM, and passive resistive torque (PRT) were also measured with a dynamometer. The interventions were 4×30s of PNF stretching (5s of contraction) and two sets of three exercises with 20 or 40 fast ground contacts (PNF stretching+PSA) and PNF stretching only. ROM was found to have increased in both groups (+4%). In addition, the PNF stretching+PSA group showed a decrease in PRT at a given angle (-7%) and a decrease in GM and mean shear modulus (GM+GL; -6%). Moreover, the MVIC peak torque decreased (-4%) only in the PNF stretching group (without PSA). Therefore, we conclude that, if PNF stretching is used as a warm-up exercise, target-muscle-specific PSA should follow to keep the performance output at the same level while maintaining the benefit of a greater ROM.

Tissue flossing of the thigh increases isometric strength acutely but has no effects on flexibility or jump height.

The purpose of this study was to investigate the effects of a single floss band treatment of the thigh on hip and knee range of motion (ROM), knee extensor passive resistive torque (PRT), knee extensor maximum voluntary contraction (MVC) torque, and countermovement jump (CMJ) height.Sixteen healthy male volunteers were tested before and after both the flossing treatment and the control condition, in random order. For the flossing treatment, the floss band was wound around both thighs for 120 s, and the subject was then asked to perform 20 squats. During the control treatment, only the 20 squats were performed. Before and after the treatments, knee and hip ROM were assessed using a Thomas test with 3D motion caption. The PRT and MVC of the knee extensors were measured with a dynamometer, and the electromyographic (EMG) signal was collected from the vastus lateralis. CMJs were performed on a force plate.Compared to the control condition, the flossing treatment showed a positive effect on the MVC of the knee extensors (P = 0.01); however, no effects on hip ROM (P = 0.58), knee ROM (P = 0.37), CMJ height (P = 0.75), or PRT (P = 0.22) were observed. Correlation analyses revealed that the increase in MVC was not significantly related to changes in the tension of the muscle-tendon unit (rP = -0.13; P = 0.64) or vastus lateralis EMG (rS = 0.44; P = 0.10). Since the increase in MVC cannot be explained by changes of the mechanical (PRT) or neuromuscular (EMG) properties, we speculate that an enhancement of growth hormone and norepinephrine levels following the compression release is instead responsible for the increase in MVC.

Joint Flexibility and Isometric Strength Parameters Are Not Relevant Determinants for Countermovement Jump Performance.

Vertical jumps are of great importance as a performance predictor for many types of sports that require speed and agility. However, to date, it is not clear if flexibility and/or the strength of the different leg muscles are determinants for countermovement jump (CMJ) performance. Therefore, the purpose of this study was to relate isometric maximum voluntary contraction (MVC) torque and the flexibility of various muscle groups of the lower body with CMJ performance. Thirty-six healthy male volunteers participated in this study. The participants performed MVCs of the knee extensors, knee flexors, and plantar flexors on a dynamometer. Moreover, range of motion of the hip flexors and plantar flexors was assessed with 3D motion capture, and the range of motion of the knee flexors (hamstrings) was assessed with a Sit n' Reach® box. CMJs were assessed with a force platform. The correlation analysis revealed a significant moderate correlation of CMJ height with the flexibility of the hip flexors (rP = -0.39) and plantar flexors (rP = 0.47), but not the knee flexors. Moreover, we found that absolute MVC values are not related to CMJ height. However, we did find that knee extensor MVC relative to body mass is significantly related to CMJ height (rP = 0.33) with a moderate magnitude. Although we found significant correlations, the magnitudes of correlations vary between trivial and large according to a 90% confidence interval. Thus, this indicates that range of motion or strength of the assessed leg muscles can explain CMJ performance only to a limited extent.