Comparison of the Effects of a Roller Massager Intervention on the Rectus Femoris Between Lengthened and Slack Positions.

ABSTRACT: Kasahara, K, Konrad, A, Murakami, Y, Thomas, E, and Nakamura, M. Comparison of the effects of a roller massager intervention on the rectus femoris between lengthened and slack positions. J Strength Cond Res XX(X): 000-000, 2024-A roller massager (RM) is a type of foam rolling device, which previous studies have shown to be effective for acutely decreasing tissue hardness and increasing range of motion (ROM). However, these effects may differ with the RM intervention position (i.e., knee flexion or knee extension). Therefore, this study aimed to compare the acute effects of an RM intervention on the rectus femoris (RF) in the knee flexed and extended positions. The subjects were 14 healthy male college students (age, 22.6 ± 0.8 years). The RF of the dominant leg was tested. Three conditions were compared: a control condition with no intervention (CON), an RM intervention in knee extension (i.e., RM_extension), and a RM intervention in knee flexion (i.e., RM_flexion). The measurements were tissue hardness in the proximal (TH_pro), middle (TH_mid), and distal (TH_dis) portions of the RF, knee flexion ROM, pain pressure threshold (PPT), maximal voluntary isometric contraction (MVC-ISO) torque, and maximal voluntary concentric contraction (MVC-CON) torque in the RF before and immediately after the intervention. There were significant interaction effects of TH_mid and knee flexion ROM. Both RM_extension and RM_flexion conditions showed a significant (p < 0.01) decrease in TH_mid and an increase in knee flexion ROM, but there were no significant differences between conditions. There was a main effect for TH_pro and PPT (p < 0.05) but no significant interaction effect or main effect for TH_dis, MVC-ISO torque, and MVC-CON torque. The results showed that the RM intervention can effectively decrease tissue hardness and increase ROM, regardless of limb position (i.e., knee extension or flexion).

Comparison of the effects of different foam rolling durations on knee extensors function.

Foam rolling (FR) intervention has recently attracted attention in sports and rehabilitation settings. However, the effects of FR using different rolling durations have not been fully clarified. Thus, this study focused on FR durations and examined the acute and prolonged (i.e., 20-min; 40-min, 60-min) effects of different FR intervention durations on maximal voluntary concentric contractions (MVC-CON), knee flexion range of motion (ROM), pain pressure threshold (PPT), and tissue hardness. The participants were 10 male university students (22.5 ± 1.0 years), and the target muscles were the dominant leg knee extensors. Three sets of 60-seconds FR interventions were performed in the randomized crossover trials in each condition. The three intervention conditions were fast (1 rolling/2 s, 30-repetition × 3 sets, 90 repetitions), medium (1 rolling/6 s, 10-repetition × 3 sets, 30 repetitions), and slow speed (1 rolling/12 s, 5-repetition × 3 sets, 15 repetitions). Before as well as immediately, 20-min, 40-min, and 60-min after the interventions, MVC-CON, ROM PPT, and tissue hardness were measured. The results showed no interaction effect in the acute effect but a main effect of time for all variables (p < 0.05). Also, no interaction was observed in prolonged effect, but main effects of time were observed in knee flexion ROM, PPT, and tissue hardness (p < 0.01) but not for MVC-CON. Post-hoc tests showed significant PPT (p < 0.05) and knee flexion ROM (p < 0.01) increases up to 20- and 60-minutes respectively after all interventions. Tissue hardness was significantly (p < 0.01) decreased up to 60-minutes after all interventions. This study showed that the FR intervention changed ROM, PPT, tissue hardness, and MVC-CON regardless of rolling duration and that the effects persisted up to 20-60 minutes.

Comparison of acute and prolonged effects of short-term foam rolling and vibration foam rolling on the properties of knee extensors.

Recently, Foam Rolling (FR) and Vibration Foam Rolling (VFR) have attracted attention in sports and rehabilitation fields. Previous studies have shown that FR and VFR acute interventions effectively increase the range of movement (ROM) and decrease tissue hardness. For application to sports and rehabilitation, it is necessary to compare the acute and prolonged effects of short duration FR and VFR. Therefore, this study aimed to compare and investigate the acute and prolonged (15 minutes) effects of short duration (30-s) FR and VFR interventions on knee extensors. The subjects were 14 male university students (22.4 ± 1.0 years old), in which the knee extensors of the dominant leg were tested. In a cross-over trial, 30-s of FR or VFR were performed with 2-s rolling of the anterior thigh (15 rolls). The frequency of VFR was 35 Hz. Measurements included knee flexion ROM, pain pressure threshold (PPT), tissue hardness, and countermovement jump height. The results of this study showed no interaction effects for all variables, but main time effects were observed for knee flexion ROM, PPT, and tissue hardness. Post-hoc tests showed that knee flexion ROM increased up to 10 minutes after the intervention. PPT significantly increased, and tissue hardness significantly decreased up to 15 minutes after intervention. This study showed that 30-s FR and VFR interventions effectively increased ROM, PPT, and decreased tissue hardness. The effects were prolonged up to 10-15 minutes after the intervention. The results of this study show no advantage of VFR over FR with acute short-term interventions.

Acute effects of static stretching and proprioceptive neuromuscular facilitation on non-local range of movement.

Acute effects of static stretching (SS) and proprioceptive neuromuscular facilitation (PNF) on local and non-local range of motion (ROM) were assessed in 29 participants. Three evaluations were performed one week apart: week-1 Control session (CS); weeks 2-3 either SS or PNF interventions (randomized). Dominant and non-dominant limbs, local (hamstring extensibility) and non-local ROMs (Shoulder extension-ShE) were collected at baseline (T0), immediately after (T1), and fifteen minutes post-intervention (T2). No differences were found between time-points during the CS. Local-ROM significantly increased (p=0.0002, ES=0.74 and 0.0079, 0.56, for dominant and non-dominant lower limbs, respectively) after both SS and PNF. No interaction between time and treatment was detected for ShE in both limbs. However, post-hoc analysis revealed a significant increase in dominant upper limb ShE between T0 and T1 only after SS (p=0.002; +6.5%). Acute bouts of SS and PNF can increase local-ROM, however, no clear effects were observed for non-local ROM.

Does Stretching Training Influence Muscular Strength? A Systematic Review With Meta-Analysis and Meta-Regression.

ABSTRACT: Thomas, E, Ficarra, S, Nunes, JP, Paoli, A, Bellafiore, M, Palma, A, and Bianco, A. Does stretching training influence muscular strength? A systematic review with meta-analysis and meta-regression. J Strength Cond Res 37(5): 1145-1156, 2023-The aim of this study was to review articles that performed stretching training and evaluated the effects on muscular strength. Literature search was performed using 3 databases. Studies were included if they compared the effects on strength following stretching training vs. a nontraining control group or stretching training combined with resistance training (RT) vs. an RT-only group, after at least 4 weeks of intervention. The meta-analyses were performed using a random-effect model with Hedges' g effect size (ES). A total of 35 studies ( n = 1,179 subjects) were included in this review. The interventions lasted for a mean period of 8 weeks (range, 4-24 weeks), 3-4 days per week, applying approximately 4 sets of stretching of approximately 1-minute duration. The meta-analysis for the stretching vs. nontraining control group showed a significant small effect on improving dynamic (k = 14; ES = 0.33; p = 0.007) but not isometric strength (k = 8; ES = 0.10; p = 0.377), following static stretching programs (k = 17; ES = 0.28; p = 0.006). When stretching was added to RT interventions, the main analysis indicated no significant effect (k = 17; ES = -0.15; p = 0.136); however, moderator analysis indicated that performing stretching before RT sessions has a small but negative effect (k = 7; ES = -0.43; p = 0.014); the meta-regression revealed a significant negative association with study length (ß = -0.100; p = 0.004). Chronic static stretching programs increase dynamic muscular strength to a small magnitude. Performing stretching before RT and for a prolonged time (>8 weeks) can blunt the strength gains to a small-to-moderate magnitude. Performing stretching in sessions distant from RT sessions might be a strategy to not hinder strength development.

Relationship between external and internal load indicators and injury using machine learning in professional soccer: a systematic review and meta-analysis.

This study verified the relationship between internal load (IL) and external load (EL) and their association on injury risk (IR) prediction considering machine learning (ML) approaches. Studies were included if: (1) participants were male professional soccer players; (2) carried out for at least 2 sessions, exercises, or competitions; (3) correlated training load (TL) with non-contact injuries; (4) applied ML approaches to predict TL and non-contact injuries. TL included: IL indicators (Rating of Perceived Exertion, RPE; Session-RPE, Heart Rate, HR) and EL indicators (Global Positioning System, GPS variables); the relationship between EL and IL through index, ratio, formula; ML indicators included performance measures, predictive performance of ML methods, measure of feature importance, relevant predictors, outcome variable, predictor variable, data pre-processing, features selection, ML methods. Twenty-five studies were included. Eleven addressed the relationship between EL and IL. Five used EL/IL indexes. Five studies predicted IL indicators. Three studies investigated the association between EL and IL with IR. One study predicted IR using ML. Significant positive correlations were found between S-RPE and total distance (TD) (r = 0.73; 95% CI (0.64 to 0.82)) as well as between S-RPE and player load (PL) (r = 0.76; 95% CI (0.68 to 0.84)). Association between IL and EL and their relationship with injuries were found. RPE, S-RPE, and HR were associated with different EL indicators. A positive relationship between EL and IL indicators and IR was also observed. Moreover, new indexes or ratios (integrating EL and IL) to improve knowledge regarding TL and fitness status were also applied. ML can predict IL indicators (HR and RPE), and IR. The present systematic review was registered in PROSPERO (CRD42021245312).

Acute Effects of Different Foam Roller Intervention Techniques on Knee Extensors.

The usefulness of Foam Roller (FR) even without a rolling stimulus (e.g., static compression with or without dynamic joint movements) has been recently demonstrated; however, the different effects of these methods remain unclear. Thus, this study aimed to compare and investigate the effects of such FR intervention methods on knee extensors. The dominant knee extensors of 20 male university students were investigated using the following four conditions: control (CON), FR with rolling (FR_rolling), FR with static compression (FR_SC), and FR with static compression + dynamic movement of the knee joint (FR_DM). FR_SC was intervened to compress the muscle belly of the knee extensors. FR_DM involved knee flexion and extension while maintaining the FR_SC condition. Knee flexion ROM, pain pressure threshold (PPT), tissue hardness, and countermovement jump (CMJ) height were outcome variables; they were compared before and immediately after the intervention. The results of this study showed that knee flexion ROM was significantly (p < 0.01) increased in FR_rolling (d = 0.38), FR_SC (d = 0.28), and FR_DM (d = 0.64). Tissue hardness was significantly (p < 0.01) decreased in FR_rolling (d = -0.55), FR_SC (d = -0.28), and FR_DM (d = -0.42). A main effect of time (p < 0.01) was observed in knee flexion ROM, PPT, and tissue hardness, but no change in CMJ was observed. The results of this study suggested that clinicians and athletes could choose any method they like as a warm-up routine.

Comparison between 6-week foam rolling intervention program with and without vibration on rolling and non-rolling sides.

PURPOSE: The chronic effects of unilateral foam rolling (FR) or FR with vibration (VFR) intervention on the rolling and non-rolling sides (cross-education effects) are still unclear. Thus, this study aimed to investigate the effects of unilateral 6-week FR or VFR intervention on ankle dorsiflexion range of motion (DF ROM), muscle stiffness, and muscle strength in both rolling and non-rolling sides. METHODS: Thirty healthy young men were randomly allocated into the FR (n = 15) or the VFR intervention group (n = 15). Participants performed three sets of unilateral FR or VFR interventions for 60 s of the calf muscles twice/week, for 6 weeks. DF ROM, gastrocnemius muscle stiffness, and maximal voluntary isometric contraction (MVIC) torque were assessed in the rolling and non-rolling sides before and after the intervention. RESULTS: The DF ROM increased significantly (p < 0.05) to the same extent in the FR and VFR intervention groups on both rolling (FR: d = 0.58, VFR: d = 0.63) and non-rolling (FR: d = 0.39, VFR: d = 0.50) sides. Similarly, the passive torque at DF ROM increased significantly (p < 0.05) to the same extent in the FR and VFR intervention groups on both rolling (FR: d = 0.85, VFR: d = 0.77) and non-rolling (FR: d = 0.76, VFR: d = 0.68) sides. However, there were no significant changes in muscle stiffness and MVIC after FR and VFR interventions on both the rolling and non-rolling sides. FR and VFR interventions could increase the ROM in both the rolling and non-rolling sides but could not change muscle stiffness and strength. CONCLUSIONS: The results showed that it is not necessarily needed to perform VFR to increase ROM in the long term.

Comparison of the Prolonged Effects of Foam Rolling and Vibration Foam Rolling Interventions on Passive Properties of Knee Extensors.

Foam rolling (FR) and vibration foam rolling (VFR) interventions have received attention as pre-exercise warm-ups because they maintain performance and increase range of motion (ROM). However, the immediate and prolonged effects and the comparisons between FR and VFR interventions are unknown. Therefore, this study was designed to compare the effects of FR and VFR interventions on passive properties of knee extensors over time (up to 30 min after interventions). A crossover, random allocation design was used with 14 male college students (22.1 ± 1.0 years old) in the control, FR, and VFR conditions. The knee flexion ROM, pain pressure threshold (PPT), and tissue hardness were measured before and immediately after, 10, 20, and 30 minutes after the intervention. The results showed that knee flexion ROM increased significantly immediately after the intervention in both the FR and VFR conditions and maintained up to 30 minutes after both conditions. PPT increased significantly (p < 0.01) immediately after the FR intervention. In the VFR condition, there was a significant increase in PPT immediately after the intervention (p < 0.01) and 10 minutes after the intervention (p < 0.05). Tissue hardness was significantly decreased (p < 0.01) immediately after and 10 minutes after the FR intervention. However, tissue hardness in the VFR condition was significantly decreased (p < 0.01) up to 30 minutes after the intervention. The results suggest that FR and VFR interventions increase knee flexion ROM, and the effect lasts at least 30 minutes, but the effects on PPT and tissue hardness are maintained a longer time in the VFR condition compared to the FR condition. Therefore, VFR can be recommended as a warm-up before exercise to change the passive properties of knee extensors.

Time spent on the smartphone does not relate to manual dexterity in young adults.

BACKGROUND: The Grooved Pegboard Test (GPT) is widely adopted to evaluate manual dexterity, it presents normative data but the test is influenced by different factors. The influence of time spent on smartphones has not been considered before, for this reason, the objective of this study was to evaluate if smartphone use influences the time to complete the GPT. A total of 38 (21 women; 17 men) young adults 20.7 (1.5) years participated in the study. The time spent on the smartphones during the last seven days was recorded through the device itself and the GPT performance was measured. A correlation analysis between the time spent on the smartphone and GPT was performed while the t-test was adopted to evaluate gender differences. RESULTS: No statistically significant differences were detected between men and women in the time to complete the GPT (p = 0.20) and in the time spent on the smartphone (p = 0.87). The GPT and the time spent using the smartphone were not correlated (r = 0.044, p = 0.78). CONCLUSION: The time spent on the smartphone by young adults does not influence the time to complete the GPT, indicating that smartphone use does not influence measures of manual dexterity.

The effect of resistance training programs on lean body mass in postmenopausal and elderly women: a meta-analysis of observational studies.

Aging and menopause are associated with morphological and functional changes which may lead to loss of muscle mass and therefore quality of life. Resistance training (RT) is an effective training mode to increase muscle mass. We reviewed the existing literature to identify studies implementing RT protocols and evaluating muscle hypertrophy exclusively in healthy, postmenopausal and elderly women. Participants' age range was comprised between 50 and 80 years. The primary outcome observed was muscle hypertrophy. Fat mass was also evaluated, if available. PubMed and Web of Science were the screened database, and original articles written in English and published from 2000 up to 2020 were included. 26 articles were considered eligible and included. Quality assessment revealed a "moderate quality" of the included studies, however the majority of studies was able to reach level 4 of evidence and on overall grade of recommendation C. In total, data from 745 female participants subjected to different forms of resistance training were considered. Heterogeneity across studies was present regarding study design, intervention length (mean 16 weeks), training frequency (3 d/w), no. of exercises (n = 7.4) and participants' age (65.8 ± 4.9 years). Small-to-moderate significant increases (k = 43; SMD = 0.44; 95% CI 0.28; 0.60; p < 0.0001) of lean body mass were observed in post-menopausal and elderly women, regardless of age, intervention period, weekly training frequency and no. of exercises. No effects were noted for fat mass (k = 17; SMD = 0.27; 95% CI - 0.02; 0.55; p = 0.07). Studies need to concentrate on providing information regarding training parameters to more effectively counteract the effects of aging and menopause on skeletal muscle mass.

Cardiovascular Responses to Muscle Stretching: A Systematic Review and Meta-analysis.

The aim of this study will be to review the current body of literature to understand the effects of stretching on the responses of the cardiovascular system. A literature search was performed using the following databases: Scopus, NLM Pubmed and ScienceDirect. Studies regarding the effects of stretching on responses of the cardiovascular system were investigated. Outcomes regarded heart rate(HR), blood pressure, pulse wave velocity (PWV of which baPWV for brachial-ankle and cfPWV for carotid-femoral waveforms), heart rate variability and endothelial vascular function. Subsequently, the effects of each outcome were quantitatively synthetized using meta-analytic synthesis with random-effect models. A total of 16 studies were considered eligible and included in the quantitative synthesis. Groups were also stratified according to cross-sectional or longitudinal stretching interventions. Quality assessment through the NHLBI tools observed a "fair-to-good" quality of the studies. The meta-analytic synthesis showed a significant effect of d=0.38 concerning HR, d=2.04 regarding baPWV and d=0.46 for cfPWV. Stretching significantly reduces arterial stiffness and HR. The qualitative description of the studies was also supported by the meta-analytic synthesis. No adverse effects were reported, after stretching, in patients affected by cardiovascular disease on blood pressure. There is a lack of studies regarding vascular adaptations to stretching.

Validity and Reliability of an Inertial Sensor Device for Specific Running Patterns in Soccer.

Electronic performance tracking devices are largely employed in team sports to monitor performance and improve training. To date, global positioning system (GPS) based devices are those mainly used in soccer training. The aim of this study was to analyse the validity and reliability of the inertial sensor device (ISD) in monitoring distance and speed in a soccer-specific circuit and how their performance compare to a GPS system. 44 young male soccer players (age: 14.9 ± 1.1, range 9-16, years, height: 1.65 ± 0.10 m, body mass: 56.3 ± 8.9 kg) playing in a non-professional soccer team in Italy, participated in the study. We assessed the players trough a soccer running sport-specific circuit. An ISD and a GPS were used to assess distance and speed. Data was compared to a video reference system, and the difference were quantified by means of the root mean square error (RMSE). Significant differences were found for both GPS and ISD devices for distance and speed. However, lower error for distance (dRMSE 2.23 ± 1.01 m and 5.75 ± 1.50 m, respectively) and speed (sRMSE 0.588 ± 0.152 m·s-1 and 1.30 ± 0.422 m·s-1, respectively) were attained by the ISD compared to the GPS. Overall, our results revealed a statistically significant difference between systems in data monitoring for either distance and speed. However, results of this study showed that a smaller error was obtained with the ISD than the GPS device. Despite caution is warranted within the interpretation of these results, we observed a better practical applicability of the ISD due to its small size, lower cost and the possibility to use the device indoor.

Dual-Task Conditions on Static Postural Control in Older Adults: A Systematic Review and Meta-Analysis.

Dual-task (DT) consists of the performance of two tasks simultaneously. An index of DT difficulty has been linked to decreased postural control. Because a wide range of DT is employed, this study aimed to evaluate its effects in static balance in older adults. PubMed, Web of Science, and Scopus were screened, and the secondary tasks were grouped as manual, reaction time, discrimination and decision making, mental tracking, verbal fluency, working memory, or "other" tasks. A total of 66 studies have been included. The meta-analysis was conducted on 28 effects and showed a significant mean effect size of d = 0.24 (p = .02, SE = 0.10; confidence interval [0.04, 0.44]), indicating a worsening in stability during DT. In conclusion, postural control was worsened by the Stroop test and the arithmetic tasks improved it. The results do not underpin any conclusive statement on the impact of DT, and a standard operating procedure was created.

Peripheral Nerve Responses to Muscle Stretching: A Systematic Review.

Stretching is commonly used to increase range of motion and flexibility. Therefore, investigations are usually oriented towards the muscle-tendon unit. Limited evidence exists regarding potential effects of stretching on peripheral nerves which lie within muscles. The objective of this investigation will be to elucidate the responses of peripheral nerves to stretching. A literature search was performed using the following databases: Scopus, NLM Pubmed and ScienceDirect. Studies regarding the effects of stretching protocols on responses of peripheral nerves were retrieved for investigation. The NHLBI tool was used for quality assessment. Outcomes included nerve stiffness, nerve displacement, pain pressure thresholds and resistive torque. A total of 10 studies were considered eligible and were included in this investigation. The quality assessment of the studies revealed an overall "fair to good" methodological quality across the included studies. All studies except for one involved healthy participants. High heterogeneity of stretching protocols was retrieved. As a consequence of stretching, nerve stiffness (-15.6%) and pain pressure thresholds (-1.9kg) increased. Nerve displacements on each movement plane for all the considered nerves and nerve deformation were also frequently observed. Peripheral nerve responses to muscle stretching include decreased nerve stiffness and increased pain pressure thresholds. Nerve displacement also frequently occurs. It is still unclear if reduced nerve displacement may lead to clinical outcomes. There is a lack of longitudinal studies regarding peripheral nerve adaptations to stretching.

The posterior talocalcaneal ligament: an MRI evaluation.

PURPOSE: A wide inter-individual variability in terms of size, orientation and insertion is observed regarding ankle ligaments. The aim of this study is to identify and describe the anatomical features of the posterior talocalcaneal ligament (PTCL) observed through the use of magnetic resonance imaging (MRI) of the ankle. METHODS: The study was retrospectively carried out on 893 ankle MRI's exams. The exams have all been performed using a 1.5-T (T) MRI. The same scanning protocols and scan planes were carried out in all the exams. The first evaluated parameter was the recognition of the PTCL. Subsequently, in all those cases where the ligament was present, its features such as insertion sites, length, and thickness were evaluated. RESULTS: The PTCL identification was possible in 77 exams (8.6% of the total number). Among these, we were able to identify some variants regarding insertion sites, length, and thickness. The PTCL could be further classified into four categories based on the most common characteristics observed. CONCLUSIONS: Our study has identified different characteristics of the PTCL that allow us to further understand the characteristics of the ligament itself. In conclusion, the need for further studies focused on the biomechanical role of the PTCL in the ankle joint appears mandatory.

The Relation Between Stretching Typology and Stretching Duration: The Effects on Range of Motion.

Different stretching strategies and protocols are widely used to improve flexibility or maintain health, acting on the muscle tendon-unit, in order to improve the range of motion (ROM) of the joints. This review aims to evaluate the current body of literature in order to understand the relation between stretching typology and ROM, and secondly to evaluate if a relation exists between stretching volume (either as a single training session, weekly training and weekly frequency) and ROM, after long-term stretching. Twenty-three articles were considered eligible and included in the quantitative synthesis. All stretching typologies showed ROM improvements over a long-term period, however the static protocols showed significant gains (p<0.05) when compared to the ballistic or PNF protocols. Time spent stretching per week seems fundamental to elicit range of movement improvements when stretches are applied for at least or more than 5 min, whereas the time spent stretching within a single session does not seem to have significant effects for ROM gains. Weekly frequency is positively associated to ROM. Evaluated data indicates that performing stretching at least 5 days a week for at least 5 min per week using static stretching may be beneficial to promote ROM improvements.

Acute effects of different administration order of stretching exercises: effects on range of motion and cross-over effect.

BACKGROUND: The aim of this manuscript is to investigate if stretching exercise administration order may influence outcomes pertinent to range of movement (ROM). METHODS: A total sample of 108 participants was randomized into five groups. Eight sets of unilateral static stretching (SS) of 30s duration each with a 30s rest were administered to the right leg. One group underwent SS of the knee extensors (KE), another to the knee flexors (KF), another first to the KE and then to the KF, another first to the KF and then to the KE while the last group was used as control (CG). Each group was assessed for ROM of both lower limbs for either the KE and KF motion (passive hip extention [PHE] and passive straight leg raise [PSLR], respectively). Measures were assessed before (T0), immediately after (T1), and 15 minutes after the intervention (T2). RESULTS: No differences were observed for time (T0 vs. T1 vs. T2) for all measures in the CG for both limbs. Time-x-group interactions were observed only in the intervention limb (P<0.0007 and 0.004, ES 0.73 and 0.55, for KE and KF, respectively). Within the intervention limb, a significant increase in the PHE was observed from T0 to T1 only in the KE and KF/KE groups. For measures of the PSLR, a significant increase was observed from T0 to T1 only in the KF and KE/KF groups. No differences neither for time or group were observed in the control limb. CONCLUSIONS: Our results highlight that exercise administration order has an effect on ROM outcomes. Measures of ROM significantly increase only for the last stretched muscle in each intervention group. No crossover effect was observed in the contralateral limb.

The Effects of Stretching Exercise on Levels of Blood Glucose: A Systematic Review with Meta-Analysis.

BACKGROUND: Physical activity plays an important role in the management of blood glucose levels. However, compelling evidence exists only for aerobic and resistance training. In this review, we aimed to identify the potential effects of stretching exercises on blood glucose levels. METHODS: A systematic literature search was performed using the following databases: Scopus, NLM PubMed, and Web of Science. Studies regarding the effects of stretching exercise in humans on blood glucose or any related variable were included. Further inclusion criteria were: (1) original articles (published from database inception to October 2022), (2) applying stretching as a unique exercise modality, (3) having either longitudinal or acute interventions, (4) including healthy and pathological populations, and (5) having within each study a pre- and post-intervention measure. Quality assessment of the studies was conducted using the Downs and Black checklist. RESULTS: A total of 13 articles were included. The quality assessment revealed an overall moderate quality of the included records. Ten articles included patients with type 2 diabetes (T2D), whereas the remaining three included at-risk populations. A total of 731 people with a mean age of 56.7 ± 6.1 years old were analysed. Fasting blood glucose, 2 h post-oral glucose uptake, post-stretching intervention blood glucose levels, and HbA1c were identified as variables related to blood glucose within the studies. After the stretching interventions, a significant reduction was observed in either blood glucose (ES = - 0.79; p = 0.0174) or HbA1c (ES = - 1.11; p = < 0.0001). Meta-analytic results highlighted greater effects in T2D patients (ES = - 1.15; p = 0.02) and for studies applying stretching as an exercise intervention (ES = - 1.27; p = 0.006) rather than considering stretching as a control exercise modality. CONCLUSION: The results of this systematic review highlight the potential of stretching exercises to reduce blood glucose levels. In particular, if stretching is applied as a specific form of exercise intervention in patients with T2D greater effects are observed. However, further studies with more solid research designs are required, therefore, caution is needed before prescribing stretching as an exercise intervention for glycaemic management.

Sex differences in the determination of prescribed load in ballistic bench press.

Introduction: The objectives of the present study were twofold: first, to identify the specific relative load at which the concentric motion transforms into a purely propulsive action among women, and second, to compare the load-velocity relationships between men and women during the bench press throw. Methods: Fourteen men and fourteen women participated in a test where they progressively increased the load until reaching their one-repetition maximum (1RM) in the bench press exercise. Linear regression models were employed to elucidate the relationships between load and velocity, as well as load and the propulsive phase (% of total concentric time). Additionally, ANCOVA was utilized to compare the linear regression models between men and women. Results: The results revealed strong and linear associations between load and mean propulsive velocity (MPV) for both men and women, as well as between load and the propulsive phase. Notably, there were significant differences in MPV and the propulsive phase concerning load between men and women. Women transitioned into a fully propulsive concentric phase at approximately 80% of their 1RM, while men achieved this entirely propulsive phase at around 85% of their 1RM. Furthermore, women exhibited reduced velocities when handling lighter relative loads compared to men. Conversely, women demonstrated higher velocities when dealing with loads exceeding 85% of their 1RM in contrast to their male counterparts. Discussion: These findings hold notable implications for prescribing bench press throw loads for women, which should differ from those recommended for men. Further studies are necessary to validate the efficacy of the proposed load recommendations.