Effects of Vibration Rolling with and without Dynamic Muscle Contraction on Ankle Range of Motion, Proprioception, Muscle Strength and Agility in Young Adults: A Crossover Study

Revisiting the stretch-induced force deficit: A systematic review with multilevel meta-analysis of acute effects

BACKGROUND

When recommending avoidance of static stretching prior to athletic performance, authors and practitioners commonly refer to available systematic reviews. However, effect sizes (ES) in previous reviews were extracted in major part from studies lacking control conditions and/or pre-post testing designs. Also, currently available reviews conducted calculations without accounting for multiple study outcomes, with ES: -0.03 to 0.10, which would commonly be classified as trivial.

METHODS

Since new meta-analytical software and controlled research articles have appeared since 2013, we revisited the available literatures and performed a multilevel meta-analysis using robust variance estimation of controlled pre-post trials to provide updated evidence. Furthermore, previous research described reduced electromyography activity-also attributable to fatiguing training routines-as being responsible for decreased subsequent performance. The second part of this study opposed stretching and alternative interventions sufficient to induce general fatigue to examine whether static stretching induces higher performance losses compared to other exercise routines.

RESULTS

Including 83 studies with more than 400 ES from 2012 participants, our results indicate a significant, small ES for a static stretch-induced maximal strength loss (ES = -0.21, p = 0.003), with high magnitude ES (ES = -0.84, p = 0.004) for stretching durations ≥60 s per bout when compared to passive controls. When opposed to active controls, the maximal strength loss ranges between ES: -0.17 to -0.28, p < 0.001 and 0.040 with mostly no to small heterogeneity. However, stretching did not negatively influence athletic performance in general (when compared to both passive and active controls); in fact, a positive effect on subsequent jumping performance (ES = 0.15, p = 0.006) was found in adults.

CONCLUSION

Regarding strength testing of isolated muscles (e.g., leg extensions or calf raises), our results confirm previous findings. Nevertheless, since no (or even positive) effects could be found for athletic performance, our results do not support previous recommendations to exclude static stretching from warm-up routines prior to, for example, jumping or sprinting.

Acute Effects of Foam Rolling vs. Vibration Foam Rolling on Blood Flow Parameters in Professional Soccer Players: A Randomized Crossover Design

ABSTRACT

Padrón-Cabo, A, Alonso-Calvete, A, Radzimiński, Ł, Rey, E, and Lorenzo-Martínez, M. Acute Effects of foam rolling vs. vibration foam rolling on blood flow parameters in professional soccer players: a randomized crossover design. J Strength Cond Res XX(X): 000-000, 2024-The study aimed to compare the effects of foam roller (FR) and vibration foam roller (VFR) on blood flow parameters, measured by Doppler ultrasonography in professional soccer players. A randomized crossover design was used, and 10 professional soccer players participated in 3 experimental sessions: FR, VFR, and a control condition (CC). The maximum velocity (MVel) and maximum volume (MVol) blood flow parameters were measured in the common femoral artery of the dominant leg at 5 different time points as follows: before (pre), immediately after (post 0'), 10 (post 10'), 20 (post 20'), and 30 minutes (post 30') after the intervention. Both FR and VFR involved two 45-second sets with 15-second rest between sets in the quadriceps and hamstring, while CC required sitting for 240 seconds. The FR condition showed a significant increase in MVel (p < 0.01) at all time points after the intervention, and an increase in MVol (p < 0.05) only at post 0' compared with pre. The VFR condition showed a significant (p < 0.05) increase in MVel at post 0' and post 10' and an increase (p < 0.05) in MVol at post 0' compared with pre. In comparison with CC, the FR and VFR conditions presented significantly (p < 0.05) higher MVel values at post 0', post 10', post 20', and post 30' than CC. For both FR and VFR conditions, the MVol not only revealed a significant (p < 0.05) increase at post 0' but also at post 10' for VFR compared with CC. In summary, the FR and VFR interventions demonstrated a similar increase in blood flow parameters, suggesting that both strategies may accelerate physiological recovery in elite soccer players.

Comparing the effectiveness of tissue flossing applied to ankle joint versus calf muscle on exercise performance in female adults: An observational, randomized crossover trial

BACKGROUND

The prevalence of ankle sprains in females has higher than in males. A deficit in ankle dorsiflexion range of motion (DFROM) is a substantial contributor to ankle injuries, resulting in hampering exercise performance. Tissue flossing improves joint ROM and enhances performance. However, evidence of how floss band (FB) intervention influences the ankle joint and calf muscle is still lacking, particularly in women. We investigated comparing the effectiveness of FB applied to ankle joint versus calf muscle on exercise performance.

METHODS

This study was a randomized, counterbalanced crossover trial. Eighteen recreationally women received functional movements without wrapping FB (WF), movements with wrapping the FB around the ankle joint (FAG), and movements with wrapping the FB around the calf muscle (FCM). Main outcome measures included ankle dorsiflexion range of motion (DFROM), pressure pain threshold (PPT), agility test before and 5 (POST5), 30 (POST30), and 60 (POST60) minutes after each of the three interventions in random order. Two-way repeated measures analysis of variance and effect size (Cohen's d) were statistically analyzed.

RESULTS

FAG significantly increased ankle DFROM at POST5 (p = 0.01, d = 0.5), POST30 (p = 0.03, d = 0.48), and POST60 (p = 0.001, d = 0.75). FCM significantly increased at POST30 (p = 0.01, d = 0.35) and POST60 (p = 0.004, d = 0.37). Furthermore, FAG significantly improved agility at POST5 (p < 0.001, d = 0.39), POST30 (p = 0.004, d = 0.44), and POST60 (p = 0.007, d = 0.45); however, FCM only did at POST5 (p = 0.04, d = 0.29). The pressure pain threshold on the calf muscle did not significantly change.

CONCLUSIONS

FAG and WF enhance ankle ROM and agility immediately. Moreover, FAG demonstrates a prolonged effect of agility for 1 h. Practitioners may take this information into account for choosing efficient applications.

Immediate effects of counterforce brace with and without vibration on pain, muscle strength and range of motion in participants with lateral epicondylitis. A pilot study

Lateral epicondylitis is one of the most common elbow problems. Counterforce braces are commonly used to manage lateral epicondylitis. Recent studies showed that vibration can decrease pain and increase muscle strength by improving motor abilities. The aim of this study was to evaluate the effects of a counterforce brace with and without vibration on pain, muscular strength, wrist and elbow joints range of motion in the participants with lateral epicondylitis. In this repeated measure pre-post clinical trial study, 28 participants with lateral epicondylitis were included. Pain were measured with Visual Analogue Scale (VAS), wrist and elbow flexor/extensor muscles strength with digital dynamometer, wrist and elbow flexion/extension range of motion with goniometer in 3 condition baseline, counterforce brace and counterforce brace with vibration. Pain using counterforce bracing with vibration showed a significant reduction as compared with baseline and counterforce bracing (P < 0.001). Wrist flexor muscles strength (P = 0.005), elbow flexor/extensor muscles strength respectively (P = 0.04, P = 0.02), wrist flexion/extension range of motion (P < 0.001) following the use of counterforce bracing with vibration increased significantly compared with baseline. The results show that the counterforce bracing with and without vibration relieves pain and improves range of motion and muscles strength in lateral epicondylitis participants, but this improvement is more significant with the use of vibration.

Acute Effect of Four Stretching Protocols on Change of Direction in U-17 Male Soccer Players

BACKGROUND

The ability to rapidly change direction while sprinting is a desirable athletic skill in soccer. Enhancing change of direction (COD) performance depends almost exclusively on specific training, with stretching traditionally considered one such intervention. However, the comparative impact of diverse stretching methods on COD in soccer players remains an area of interest. Therefore, this study aimed to compare the effects of different stretching methods on COD ability in soccer players.

METHODS

Twelve male soccer players playing in the national championship football division II (age: 16.3 ± 0.3 years, height: 1.81 ± 0.10 m, body mass: 67.7 ± 7.2 kg) were tested for COD performance (i.e., Illinois agility test) after (1) control condition (20 min general warm-up without stretching), (2) static stretching, (3) dynamic stretching, (4) combined static-dynamic stretching, and (5) combined dynamic-static stretching. The duration of stretching intervention was approximately 6 min for static and dynamic stretching and 12 min for both the combined stretching conditions. The experimental sessions were separated by 72 h.

RESULTS

COD improved after dynamic stretching when compared to any other condition (p: 0.03-0.002; ηp2: 0.56-0.73), except for the control condition (p = 0.146; ηp2 = 0.18). In contrast, static stretching induced a detrimental effect on COD when compared only to the dynamic stretching condition (p < 0.01; ES = 1.35).

CONCLUSION

Dynamic stretching exercises used by male soccer players in the warm-up improved COD. Other forms of stretching exercises, particularly static stretching, negatively impacted the COD performance. Therefore, coaches can consider integrating dynamic stretching protocols tailored to the athletes' specific needs. Moreover, extending the investigation to encompass a wider range of athletes, including different age groups and genders, would enhance the applicability and generalization of the findings.

Acute Effects of Combining Dynamic Stretching and Vibration Foam Rolling Warm-up on Lower-Limb Muscle Performance and Functions in Female Handball Players

ABSTRACT

Chen, CH, Chiu, CH, Tseng, WC, Wu, CY, Su, HH, Chang, CK, and Ye, X. Acute effects of combining dynamic stretching and vibration foam rolling warm-up on lower-limb muscle performance and functions in female handball players. J Strength Cond Res 36(4): 920-926, 2022-The purpose of this study was to compare the acute effects of 3 warm-up protocols on knee flexor and extensor muscles performance in elite female collegiate handball players. Ten female handball players with poor hamstring flexibility completed 3 randomly sequenced experimental visits. During each visit, a different warm-up protocol (general running warm-up [GW], dynamic stretching [DS], or DS combined with vibration foam rolling [DS + VR]) was delivered before the subsequent tests: quadriceps and hamstring muscle stiffness, knee extension and flexion range of motion (ROM), knee joint position sense, knee extension and flexion isokinetic strength with hamstring-quadriceps strength ratio, and muscle endurance during fatiguing exercise. Relative to the GW, the DS + VR protocol resulted in significantly greater knee flexion ROM (mean ± SD : DS + VR = 79.4° ± 7.7°; GW = 69.3° ± 9.6°) and lower hamstring muscle stiffness (DS + VR = 253.33 ± 36.20 N·m -1 ; GW = 292.89 ± 24.28 N·m -1 ). In addition, the DS + VR protocol also yielded greater hamstring muscle endurance than the other 2 protocols did (fatigue percentage: DS + VR = 30.24% ± 10.84%; GW = 41.40% ± 8.98%; DS = 42.22% ± 9.42%). Therefore, the results of this experiment suggest that it can be more beneficial for the female handball players to warm-up with the DS + VR, rather than the GW and DS protocols.

Comparison of The Effect of High- and Low-Frequency Vibration Foam Rolling on The Quadriceps Muscle

Vibration foam rolling (VFR) intervention has recently gained attention in sports and rehabilitation settings since the superimposed vibration with foam rolling can affect several physiological systems. However, the sustained effect and a comparison of the effects of different VFR vibration frequencies on flexibility and muscle strength have not been examined. Therefore, in this study, we aimed to investigate the acute and sustained effects of three 60-s sets of VFR with different frequencies on knee flexion range of motion (ROM) and muscle strength of the knee extensors. Using a crossover, random allocation design, 16 male university students (21.2 ± 0.6 years) performed under two conditions: VFR with low (35 Hz) and high (67 Hz) frequencies. The acute and sustained effects (20 min after intervention) of VFR on knee flexion ROM, maximum voluntary isometric contraction (MVC-ISO) torque, maximum voluntary concentric contraction (MVC-CON) torque, rate of force development (RFD), and single-leg countermovement jump (CMJ) height were examined. Our results showed that knee flexion ROM increased significantly (p &lt; 0.01) immediately after the VFR intervention and remained elevated up to 20 min, regardless of the vibration frequency. MVC-ISO and MVC-CON torque both decreased significantly (p &lt; 0.01) immediately after the VFR intervention and remained significantly lowered up to 20 min, regardless of the vibration frequency. However, there were no significant changes in RFD or CMJ height. Our results suggest that VFR can increase knee flexion ROM but induces a decrease in muscle strength up to 20 min after VFR at both high and low frequencies.

Acute effects of vibration foam rolling and local vibration during warm-up on athletic performance in tennis players

Athletes are currently fond of vibration foam rollers (VFRs) and commercial portable vibration percussion devices (PVPDs). It is still unknown whether using these devices during warm-up has an immediate impact on athletic performance. A randomized block design was used in this study. The acute effects of VFR and PVPD on tennis players’ athletic performance during warm-up were compared. For the countermovement jump (CMJ), reactive strength index (RSI), and hexagon test (HT), the difference in performance between all interventions was significant (p = 0.007–0.034, η²_p = 0.266–0.364). Only those who received VFR had significantly different CMJ and HT results when compared to the control group (CMJ height = 53.18 ±4.49 cm, p = 0.03, d = 1.26; HT time = 10.73 ±0.4 s, p = 0.03, d = 1.12). Participants’ RSI values were significantly different after VFR (RSI = 2.01 ±0.11 cm·mm^–1, p = 0.012, d = 1.76) and PVPD (RSI = 1.99 ±0.11 cm·mm^–1, p = 0.025, d = 1.52) compared to the control group. Therefore, when using VFR and PVPD as part of warm-up protocols for tennis players of varying skill levels, VFR could have an immediate positive effect on power, reactive strength, and change of direction performance, while PVPD could immediately improve reactive strength performance.

Does Vibration Foam Roller Influence Performance and Recovery? A Systematic Review and Meta-analysis

BACKGROUND

Foam rolling has been extensively investigated, showing benefits in performance and recovery. Recently, vibration has been added to foam rollers, with hypothesized advantages over conventional foam rollers. However, there is no systematic evidence in this regard.

OBJECTIVE

To carry out a systematic review and meta-analysis about the effects of vibration foam roller (VFR) on performance and recovery.

METHODS

A systematic search was conducted in PubMed/MEDLINE, Web of Science and SportDiscus according to the PRISMA guidelines. The outcomes included performance (jump, agility and strength) and recovery variables (blood flow, pain and fatigue) measured after an intervention with VFR. The methodological quality was assessed with the PEDro scale. A random-effects model was used to perform the meta-analysis.

RESULTS

Initially, 556 studies were found and after the eligibility criteria 10 studies were included in the systematic review and 9 in the meta-analysis. There was no significant effects on jump performance (SMD = 0.14 [95% CI - 0.022 to 0.307]; p = 0.101; I2 = 1.08%) and no significant beneficial effects were reported on isokinetic strength (SMD = 0.16 [95% CI - 0.041 to 0.367]; p = 0.117; I2 = 9.7%). Recovery appears to be enhanced after VFR interventions, but agility does not seem to increase after VFR interventions.

CONCLUSION

This systematic review and meta-analysis suggest that VFR could have great potential for increasing jump performance, agility, strength and enhancing recovery. Further research is needed to confirm the effects of VFR on performance and recovery. Trial Registration This investigation was registered in PROSPERO with the code CRD42021238104.

Acute Effects of Tissue Flossing Coupled with Functional Movements on Knee Range of Motion, Static Balance, in Single-Leg Hop Distance, and Landing Stabilization Performance in Female College Students

Flexibility, specifically that in the amplitude of sagittal-plane range of motion (ROM), can improve jump landing patterns and reduce the potential for sports injury. The use of floss bands (FLOSS) reportedly increases joint range of motion (ROM) in the shoulder, ankle, and elbow joints. However, little research on the effectiveness of FLOSS on the knee joint has been conducted. This study investigated the effects of FLOSS on knee ROM, static balance, single-leg-hop distance, and landing stabilization performance in women. This study had a crossover design. Twenty active female college students without musculoskeletal disorders were randomly assigned to receive a FLOSS intervention or elastic bandage (ELA) control on their dominant knees. The participants underwent FLOSS and ELA activities on two occasions with 48 h of rest between both sets of activities. The outcomes were flexibility of the quadriceps and hamstrings, how long one could maintain a single-leg stance (with and without eyes closed), distance on a single-leg triple hop, and score on the Landing Error Scoring System (LESS); these outcomes were evaluated at preintervention and postintervention (immediately following band removal and 20 min later). After the FLOSS intervention, the participants’ hamstring flexibility improved significantly (immediately after: p = 0.001; 20 min later: p = 0.002), but their quadricep flexibility did not. In addition, FLOSS use did not result in worse single-leg stance timing, single-leg triple-hop distance, or landing stabilization performance relative to ELA use. Compared with the ELA control, the FLOSS intervention yielded significantly better LESS at 20 min postintervention (p = 0.032), suggesting that tissue flossing can improve landing stability. In conclusion, the application of FLOSS to the knee improves hamstring flexibility without impeding static balance, and improves single-leg hop distance and landing stabilization performance in women for up to 20 min. Our findings elucidate the effects of tissue flossing on the knee joint and may serve as a reference for physiotherapists or athletic professionals in athletic practice settings.

A comparison of a single bout of stretching or foam rolling on range of motion in healthy adults

PURPOSE

Stretching and foam rolling are common warm-up exercises and can acutely increase the range of motion (ROM) of a joint. However, possible differences in the magnitude of change on ROM between these two interventions on the immediate and prolonged effects (e.g., 10 min after the intervention) are not yet well understood. Thus, the purpose of this review was to compare the immediate and prolonged effects of a single bout of foam rolling with a single bout of stretching on ROM in healthy participants.

METHODS

In total, 20 studies with overall 38 effect sizes were found to be eligible for a meta-analysis. For the main analysis, subgroup analysis, we applied a random-effect meta-analysis, mixed-effect model, respectively. The subgroup analyses included age groups, sex, and activity levels of the participants, as well as the tested muscles, the duration of the application, and the study design.

RESULTS

Meta-analyses revealed no significant differences between a single stretching and foam rolling exercise immediately after the interventions (ES = 0.079; P = 0.39) nor a difference 10 min (ES =  - 0.051; P = 0.65), 15 min (ES =  - 0.011; P = 0.93), and 20 min (ES =  - 0.161; P = 0.275) post-intervention. Moreover, subgroup analyses revealed no other significant differences between the acute effects of stretching and foam rolling (P > 0.05).

CONCLUSION

If the goal is to increase the ROM acutely, both interventions can be considered as equally effective. Likely, similar mechanisms are responsible for the acute and prolonged ROM increases such as increased stretch tolerance or increased soft-tissue compliance.

Effects of a Single Session of Floss Band Intervention on Flexibility of Thigh, Knee Joint Proprioception, Muscle Force Output, and Dynamic Balance in Young Adults

The floss band (FB) has been correlated with increases in the joint range of motion (ROM). However, the literature on FB effectiveness in knee joint ROM and athletic performance remains sparse. This study investigated the effects of FB on the flexibility of the quadriceps and hamstrings, knee joint proprioception, muscle force output, and dynamic balance in men. Thirty recreationally active men without musculoskeletal disorders were randomized to receive FB (Lime Green; Sanctband flossband) and elastic bandage (EB) intervention on the dominant knee joint. Participants received two interventions on two occasions with 2 days of rest between interventions. The primary outcome was the flexibility of the quadriceps and hamstrings; the secondary outcomes were knee proprioception (joint reposition angle error), knee muscle force output, and dynamic balance. Preintervention and postintervention (immediately following band removal and 20 min later) measurements were obtained. After FB intervention, hamstring flexibility (immediately: p < 0.001; 20 min later: p < 0.001) and quadriceps flexibility (immediately: p < 0.001; 20 min later: p < 0.001), quadriceps muscle force output (immediately: p = 0.007; 20 min later: p < 0.001), and dynamic balance (both immediately and 20 min later, p < 0.001) were significantly improved. Compared with EB intervention, FB intervention significantly improved knee extension ROM (immediately and 20 min later, both p < 0.001), knee flexion ROM (immediately, p = 0.01; 20 min later, p = 0.03), hamstrings muscle force output (20 min later, p = 0.022) and dynamic balance (immediately, p = 0.016; 20 min later, p = 0.004). Regarding proprioception, no significant difference among time points and conditions was observed. In conclusion, FB intervention can significantly improve the flexibility of the quadriceps and hamstrings, quadriceps muscle force output, and dynamic balance without impeding knee proprioception. Physiotherapists or athletic professionals may consider FB intervention as a potential tool as a warmup to enhance the flexibility of the quadriceps and hamstrings, quadriceps muscle force output, and dynamic balance in young adults.

Altering muscle activity in the lower extremities by bipedal landing with different drop tasks and shoes

BACKGROUND: The ability of the lower-extremity muscle activation directly affects the performance and in turn interacts with the loading conditions of the muscle itself. However, systematic information concerning the characteristics of lower-extremity muscle during landings is lacking. In particular, the landing height and shoes are also important factors based on the actual situation, which could further contribute to understanding the neuromuscular activity and how biochemical response of the body tissues to double-leg drop landings. OBJECTIVE: The study was to investigate the effects of landing tasks on the activation of lower-extremity muscles and explore the relationship among movement control, landing heights, shoe cushioning, and muscle activities. METHODS: Twelve male basketball players were recruited to perform drop jump (DJ) and passive landing (PL) from three heights (30, 45, and 60 cm) while wearing highly-cushioned basketball shoes (HC) and less-cushioned control shoes (LC). EMG electrodes were used to record the activities of the target muscles (rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, and lateral gastrocnemius) during the landing tasks. RESULTS: Pre- and post-activation activity of the lower-extremity muscles significantly decreased during PL compared with those during DJ (p< 0.05). No significant shoe effects on the characteristics of muscle activation and coactivation during DJ movements were observed. However, the participants wearing LC showed significantly higher muscle post-activation (p< 0.05) at the three drop heights during PL compared with those wearing HC. Coactivation of the ankle muscles was higher in LC than in HC during 30-cm PL (p< 0.05). CONCLUSIONS: The activation patterns of lower-extremity muscles can be significantly influenced by landing types. Highly-cushioned basketball shoes would help reduce the risk of injuries by appropriately tuning the muscles during the PL.

A Comparison of the Effects of Foam Rolling and Stretching on Physical Performance. A Systematic Review and Meta-Analysis

Foam rolling and stretching with its various techniques are frequently used as a warm-up routine to increase the range of motion of a joint. While the magnitude of the changes in range of motion between foam rolling and stretching (static and dynamic techniques) is similar, it is not clear if this also holds true for performance parameters (e.g., strength, jump height). The purpose of this meta-analysis was to compare the effects of an acute bout of foam rolling (with and without vibration) with an acute bout of stretching (with all techniques included) on performance parameters in healthy participants. We assessed the results from 13 studies and 35 effect sizes by applying a random-effect meta-analysis. Moreover, by applying a mixed-effect model, we performed subgroup analyses with the stretching technique, type of foam rolling, tested muscle, treatment duration, and type of task. We found no significant overall effect, and the analysis revealed only a trend of the performance parameters in favor of foam rolling when compared to stretching (when considering all techniques). Significantly favorable effects of foam rolling on performance were detected with subgroup analyses when compared to static stretching, when applied to some muscles (e.g., quadriceps) or some tasks (e.g., strength), when applied for longer than 60 s, or when the foam rolling included vibration. When foam rolling was compared to dynamic stretching or applied in the non-vibration mode, the same magnitude of effect was observed. While the present meta-analysis revealed no significantly different effect between foam rolling and stretching (including all techniques) prior to exercise, differences could be observed under specific conditions.

Effects of a Modified Tap Dance Program on Ankle Function and Postural Control in Older Adults: A Randomized Controlled Trial

Older adults are at a high risk of falling due to age-related degradations in physical fitness. This study aimed to examine the effects of a modified tap dance program (MTD) on ankle function and postural control in older adults. Forty-four healthy older adults (mean age = 64.1 years, with 9 men) were recruited from local communities and were randomly divided into the MTD group and the control (CON) group. The MTD group received 12 weeks of MTD training 3 times per week for 30 min per session. Outcomes were measured using the five times sit-to-stand test (FTSST) for ankle strength, the universal goniometer for ankle range of motion, and the Footscan^® to trace the center of pressure. Results revealed significant improvements in FTSST in the MTD group (mean difference = 1.01), plantar flexion (left = 9.10, right = 10.0). In addition, the MTD group displayed significantly more improvements at midtest than the CON group in FTSST (mean difference = 1.51) and plantar flexion (mean difference: left = 6.10; right = 4.5). Therefore, the MTD can be an effective exercise program for ankle function improvement, but it has limited effects on improving postural control among healthy older adults.

Local Vibratory Stimulation for Temporomandibular Disorder Myofascial Pain Treatment: A Randomised, Double-Blind, Placebo-Controlled Preliminary Study

Several methods are currently used to manage pain related to temporomandibular disorder (TMD). Vibratory stimulation is applied as a pain treatment for several musculoskeletal disorders, but it has not yet been studied in-depth for TMD symptoms. The aim of this study is to analyse the effectiveness of at-home local vibration therapy (LVT) for the management of TMDs-related myofascial pain. Methods. Fifty-four TMD patients (43 F, 11 M) with an average age of 40.7 (age range: 29–54 yr.) were randomly subdivided into two groups. The study group (AG) received 1 week of at-home LVT treatment with the NOVAFON Pro Sk2/2 : 50/100 Hz, bilaterally applied to the pain area for 16 minutes daily. The placebo group (IG) followed the same protocol using inactive devices. Temporomandibular joint pain (TMJ), muscular pain (MM), and headache (HA) were assessed. Pain was evaluated using the visual analogue scale (VAS) before (T0) and after therapy (T1). Statistical analysis and Student's t-tests were applied (statistical significance for P < 0.05). Results. AG patients reported decreased average values for all types of pain considered between T0 and T1, with a statistically significant difference for TMJ pain (P < 0.05), MM pain, and HA (P < 0.001). IG patients reported a no statistically significant decrease in the average values of MM pain and an increase in the average values of TMJ pain and HA. Conclusion. The study supports the use of local vibration therapy in the control of TMD-related TMJ pain, local muscular pain, and headache.

Isometric Strength in Volleyball Players of Different Age: A Multidimensional Model

Physical abilities modelling has a profound connection with long-term athlete development and talent identification. There is not enough data to support evidence about age-related changes in volleyball players’ isometric strength. This study aimed to define the age-related model of volleyball players multidimensional muscles’ contractile characteristics. The participants were divided according to gender (male n = 112, female n = 371) and according to age into four groups: under 15 (U15), under 17 (U17), under 19 (U19), and under 21 (U21) years old. Participants performed three isometric strength tests: handgrip, lumbar extensors, and ankle extensors. Maximal force and rate of force development results from all three tests were transformed into a single Score value as a representation of contractile potentials using principal component analysis. The main findings were that Score values of both genders showed significant differences between age groups (male: F = 53.17, p < 0.001; Female: F = 41.61, p < 0.001). Trends of those yearly changes were slightly more balanced for female subjects (3.9%) compared to male subjects (6.3%). These findings could help in strength training adjustments when working with volleyball players of a certain age, and enable coaches to detect ones that stand out positively, considering them as strong in regard to their age.

Acute Effects of Dynamic Stretching Followed by Vibration Foam Rolling on Sports Performance of Badminton Athletes

Dynamic stretching (DS) is performed to increase sports performance and is also used primarily for transiently increasing range of motion (ROM). Recently, vibration foam rolling (VFR) has emerged. Its underlying concept is that it combines foam rolling techniques with local vibration to improve ROM and muscular activation concurrently. This crossover study investigated the effects of DS or DS followed by VFR (DS + VFR) during warm-ups on flexibility, muscle stiffness, power, and agility of the lower limbs in badminton athletes. Forty badminton players performed DS or DS + VFR as warm-up exercises on two occasions in a randomized order. The target muscle groups were the bilateral shoulder, anterior and posterior thigh, posterior calf, and lower back. Main outcome measures: The primary outcome was knee range of motion (ROM), and the secondary outcomes were muscle stiffness, lower limb power (countermovement jump [CMJ]), and agility. Results indicated that the protocols improved performance. DS increased knee flexion ROM (% change = 1.92, ES = 0.3, p = 0.033), CMJ height (% change = 5.04, ES = 0.2, p = 0.004), and agility (% change = -4.97, ES = 0.4, p < 0.001) but increased quadriceps muscle stiffness (% change = 3.74, ES = 0.3, p = 0.001) and increased gastrocnemius muscle stiffness (% change = 10.39, ES = 0.5, p = 0.001). DS + VFR increased knee extension ROM (% change =2.87, ES = 0.4, p = 0.003), reduced quadriceps muscle stiffness (% change = -2.79, ES = 0.3, p = 0.017), CMJ height (% change = 2.41, ES = 0.1, p = 0.037), and agility (% change = -4.74, ES = 0.2, p < 0.001). DS + VFR was not significantly superior to DS, except for muscle stiffness reduction. Taken together, we suggest that practitioners consider DS as a first line of warm-up exercise to increase ROM, CMJ height, and agility in athletes. Moreover, the addition of VFR to DS results in a large reduction of muscle stiffness, potentially reducing the risk of sports injury. Athletes, coaches and athletic professionals may consider them when selecting effective warm-up practices to augment athletic performance.