Manual traction is effective in alleviating lumbosacral spine pain: Evidence from a randomized controlled trial.

Background: Manual traction, a therapeutic technique frequently employed in healthcare, involves applying controlled pulling force by hand, usually to the spine, to stretch muscles and decompress joints, thereby alleviating pain. This method can be particularly beneficial for addressing lumbosacral spine pain exacerbated by radicular symptoms, characterized by pain radiating from the lower back due to compression or irritation of spinal nerves. Purpose: This study aimed to compare the effects of manual traction against control group in alleviating the lumbosacral spine pain caused by radicular symptoms. Methods: A randomized controlled study design was utilized with a sample of 60 patients experiencing lumbosacral spine pain, evenly distributed between an experimental group (n = 30; receiving manual traction) and a control group (n = 30). Patients underwent assessments before and after six treatment sessions, which included the Straight Leg Raise test, modified Bragard's test, Kernig's test, and the visual analogue scale for pain perception. Results: Between-group significant differences were found at post-intervention, favoring the experimental group on SLR - Left (°) (p = 0.004; medium effect size), SLR - Right (°) (p = 0.004; medium effect size), Modified Bragard test - Left (°) (p = 0.024; small effect size), Modified Bragard test - Right (°) (p = 0.003; medium effect size), Kernig's Test - Left (°) (p = 0.013; medium effect size) and Kernig's Test - Right (°) (p = 0.010; medium effect size). Additionally, between-group significant differences were found at post-intervention, favoring the experimental group on VAS scores at SLR left (p < 0.001; medium effect size), and right (p < 0.001); medium effect size, Modified Bragard test left (p < 0.001; medium effect size) and right (p < 0.001; medium effect size) and at Kernig's Test left (p < 0.001; medium effect size) and right (p < 0.001; medium effect size). Conclusions: In conclusion, manual traction is recommended as an effective approach for alleviating lumbosacral spine pain in patients experiencing symptoms resulting from irritation or compression of a spinal nerve root.

Immediate Effect of Cryo-Compression Therapy on Biomechanical Properties and Perfusion of Forearm Muscles in Mixed Martial Arts Fighters.

Mixed martial arts (MMA) fighters use their arms and hands for striking with the fists, grappling, and defensive techniques, which puts a high load on the forearms and hand muscles. New methods are needed to decrease the risk of injury and increase the effectiveness of regeneration. This study aimed to assess the effectiveness of cryo-compression (CC) therapy of different times (3 and 6 min) on forearm muscles in MMA fighters by investigating muscle pain, stiffness, tension, elasticity strength, and perfusion. Twenty professional male MMA fighters aged 26.5 ± 4.5 years, with training experience of 10.3 ± 5.0 years, were enrolled on an experimental within-group study design. The participants underwent CC therapy at a temperature of 3 °C and compression of 75 mmHg for 3 min and, in the second session, for 6 min. The investigated parameters were in the following order: (1) perfusion in non-reference units (PU), (2) muscle tone (T-[Hz]), (3) stiffness (S-[N/m]), (4) elasticity (E-[arb]), (5) pressure pain threshold (PPT-[N/cm]), and (6) maximum isometric force (Fmax [kgf]) at two time points: (1) at rest-2 min before CC therapy (pre) and (2) 2 min after CC therapy (post). There were significant differences between 3 and 6 min of CC therapy for PU and T. Meanwhile, F, E, PPT, and S were significantly different when comparing pre- to post-conditions. These results provide evidence that CC therapy is a stimulus that significantly affects parameters characterizing muscle biomechanical properties, pain threshold, strength, and tissue perfusion.

Effect of applied cadence in repeated sprint cycling on muscle characteristics.

PURPOSE: This study aimed to investigate physiological responses, muscle-tendon unit properties of the quadriceps muscle, and mechanical performance after repeated sprint cycling at optimal and 70% of optimal cadence. METHODS: Twenty recreational cyclists performed as first sprint performance cycling test and during subsequent sessions two repeated sprint cycling protocols at optimal and 70% of optimal cadence, in random order. The muscle-tendon unit outcome measures on the dominant leg included muscle thickness, fascicle length (Lf), pennation angle (θp), and stiffness for the rectus femoris (RF), vastus lateralis (VL), and vastus medialis muscle (VM) at baseline, immediately after repeated sprint cycling, and 1-h post-exercise. RESULTS: The results showed an increase in muscle thickness and θp in RF, VL, and VM for both cadences from baseline to immediately after exercise. The Lf decreased in RF (both cadences), while stiffness decreased in RF, VL, and VM at optimal cadence, and in VL at 70% of optimal cadence from baseline to immediately after exercise. CONCLUSION: The present study revealed that the alterations in muscle characteristics were more marked after repeated sprint cycling at optimal cadence compared with a lower cadence most likely as a result of higher load on the muscle-tendon unit at optimal cadence.

Validity and reliability of Polar M400 GPS watches for measuring distances covered by team sports players.

Monitoring locomotor demands in team sports becomes popular in professional and recreational daily activities. Precise measurements are main of importance in training routine. The aim of this study is three-fold: (i) analyze the validity of Polar M400 Global Positioning System (GPS) watches for measuring distances covered in team sports simulation cycle; (ii) testing inter-unit reliability of two devices attached during testing; and (iii) testing inter-session reliability for the same simulation cycle. Methods: Twenty-one team athletes (age: 24.5 ± 5.2 years; body mass: 71.8 ± 5.7 kg; height: 176.5 ± 4.3 cm) were tested in the team sport simulation cycle (TSSC). Two Polar M400 sport watches were used by each player on their wrists at the same time. The data obtained from Polar M400 were compared to the reference fixed distance of the TSSC to determine the watch validity. Inter-session reliability was also tested using the two watches in two different sessions. Results: No significant differences between the reference value and the watches (F = 1.086; p = 0.368; ηp2 ≤0.042) were found. The %CV (0.03-0.05%) and SEM (0.05-0.09) values found for all considered groups confirmed good levels of reliability of the Polar M400 to measure total distance. Conclusions: The Polar M400 is a valid and reliable watch for measuring the distances covered by team sport athletes. Both coaches and athletes can monitor the distances covered with accuracy and precision, through the use of the Polar M400 sport watch.

Variability of peak speed and sprinting actions during the same small-sided games: within- and between-player variations inspected over four consecutive weeks.

This study aimed to analyze within- and between-player variations of peak speed and sprinting actions occurring in small-sided games (SSGs: 1 v 1 and 5 v 5). The study followed a cohort study design. Twenty male youth soccer players (age: 17 years old) from the same team were observed over four consecutive weeks. Each week, the players participated in two sessions (day one and day two) during which SSGs were applied. The 1 vs. 1 format was employed with four repetitions of thirty seconds interspaced with two-minute rest intervals, while the 5 vs. 5 format with four repetitions of four minutes and two-minute rest intervals between them. The players were monitored during all training sessions with the Polar Team Pro. The peak speed attained in each game, and the number of sprints were extracted as the primary outcomes. The between-player variability revealed a lower coefficient of variations for peak speed in the 1 vs. 1 (13.9%) and 5 vs. 5 (10.9%) formats than for sprints (1 v 1: 64.7%; 5 v 5: 65.5%). Considering the within-player variability, it was observed that sprints were more variable (1 vs. 1: 62.1%; 5 v 5: 65.7%) than peak speed (1 vs. 1: 16.4%; 5 v 5: 14.0%). The between-session analysis revealed that during week 1 (day 1), peak speed was significantly higher than during week 3 (day 1) in the 1 vs. 1 format (+3.0 km/h; p = 0.031; d = 1.296). Moreover, peak speed during week 3 (day 2) was considerably lower than during week 1 (-5.9 km/h; p < 0.001; d = 1.686) and week 2 (-5.0 km/h; p = 0.001; d = 1.639). The between-session analysis showed no significant differences in the sprint between the sessions on day 1 (p > 0.05). However, on day two, the sprint was substantially higher during week one than during week four in the 5 vs. 5 format (+5.40 n; p = 0.002; d = 2.571). In conclusion, this study revealed that peak speed presents lower within- and between-player variability than the number of sprints. Considering these two measures, there are no considerable variations between the weeks. Coaches should consider identifying strategies to stabilize the stimulus regarding the number of sprints if this represents one of the targets for employing SSGs.

Multiple cryosauna sessions for post-exercise recovery of delayed onset muscle soreness (DOMS): a randomized control trial.

The main goal was to investigate the effectiveness of cryosauna in preventing the development of delayed onset muscle soreness and to analyze the regenerative changes within muscles after acute fatigue-induced exercises. Thirty-one volunteers were assigned into two groups: 1) an intervention group that participated in cryostimulation after fatigue-induced exercise protocol (CRYO, n = 16) and a control group that performed fatigue-induced exercise protocol, but without any intervention (CONT, n = 15). Main outcome measures include at baseline: blood sample testing (leukocyte content, myoglobin concentration, and creatine kinase activity) and muscle stiffness of lower extremity; immediately after (stiffness), and 24-48-72-96 h post-exercise (blood samples and stiffness). Both groups performed an exercise-induced muscle damage protocol based on repeated countermovement jumps (10 sets, 10 repetitions). The CRYO group underwent a cryosauna (temperature: -110°C, time: 1.5 min per session) intervention during four sessions (i.e., immediately after, 24-48-72 h post-exercise). Leukocyte content was significantly greater 24-48-72 h after exercise in CONT, compared with the CRYO group (p ≤ 0.05 for all), while creatine kinase activity was greater 24-48-96 h in CONT, compared with the CRYO group (p ≤ 0.05 for all). Muscle stiffness increased significantly in rectus femoris, tibialis anterior, and fibula muscle after 48 h post-exercise (p ≤ 0.05 for all), as well as in tibialis anterior and fibula after 72 h post-exercise (p ≤ 0.05 for all) in the CRYO group. Multiple cryosauna was an effective recovery strategy that reduced blood biomarkers and muscle stiffness after exercise-induced muscle damage. Moreover, the development of delayed onset muscle soreness, expressed by a greater muscle stiffness post-exercise, was attenuated to the first 48 h.

Arbitrary absolute vs. individualized running speed thresholds in team sports: A scoping review with evidence gap map.

The aims of this scoping review were (i) to characterize the main methodological approaches to assessing individualized running speed thresholds in team sports players; (ii) to assess the use of traditional arbitrary (absolute) thresholds compared to individualized running speed thresholds in team sports players; (iii) to provide an evidence gap map (EGM) about the approaches and study designs employed in investigations in team sports and (iv) to provide directions for future research and practical applications for the strength and conditioning field. Methods studies were searched for in the following databases: (i) PubMed; (ii) Scopus; (iii) SPORTDiscus and (iv) Web of Science. The search was conducted on 15/07/2022. Risk of bias was assessed using the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS). From 3,195 potentially relevant articles, 36 were eligible for inclusion in this review. Of the 36 included articles, 27 (75%) focused on the use of arbitrary and individualized running speed thresholds to describe the locomotor demands (e.g., high intensity running) of players. Thirty-four articles used individualized speed running thresholds based on physical fitness assessments (e.g., 40-m linear sprint) or physical performance (e.g., maximal acceleration). This scoping review supported the need for a greater focus to be placed on improving the methodological aspects of using individualized speed running thresholds in team sports. More than just creating alternatives to arbitrary thresholds, it is essential to increase the replicability of methodological conditions whilst ensuring that research comparing the most adequate measures and approaches to individualization takes into consideration the population and context of each study.

Match running performance profiles of amputee football players at the national level.

Even though running performance and positional profiles in football are well described, amputee football (AF) has different characteristics of the movement, pitch dimensions, and time played. There is a gap in the scientific literature about positional profiles based on running performance in AF. This study aimed to investigate the differences between positions, the influence of the amputation level or defect of the lower limb (LD), the differences in running performance between halves, and the relationship with the final match result. Thirteen AF National Team players were monitored by Global Navigation Satellite System (GNSS), tracking 24 official international matches for 17 months. Values of top speed, peak acceleration, peak deceleration, average distance per minute, sprint mean speed, GPS load per minute, inertial load per minute (Gs load/min), number of sprints per minute, and a number of impacts per minute were analyzed for defenders (DEF), midfielders (MID) and forwards (FOR). Additional factors analyzed were amputation level (below the knee, low amputation-LA or over the knee, high amputation-HA or defect of the lower limb-LD) and the match's final result. Midfielders had significantly higher running performance parameters compared to other positions (greater top speed than DEF (+ 0.3 m/s; p < 0.001) and FOR (+ 0.2 m/s; p = 0.045), greater peak acceleration and deceleration than DEF (+ 0.5 m/s2 for both measures; p < 0.001) and FOR (+ 0.4 and + 0.3 m/s2; p < 0.001 and p = 0.036, respectively), greater GPS load/minute than DEF (+ 0.2 load/min; p = 0.001) and FOR (+ 0.3 load/min; p < 0.001), greater Gs load per minute than DEF (+ 2.7 load/min; p < 0.001) and FOR (+ 1.8 load/min; p < 0.001), greater number of impacts per minute than DEF (+ 0.2 n/min; p < 0.001) and FOR (+ 0.2 n/min; p < 0.001). Players with LD had significantly higher running performance than those with LA or HA. In the match's second half, a decrease in running performance was registered. The trend of running more when losing could be observed-AF players had higher running parameters in lost matches, but the differences were not statistically significant. Further research complied with contextual game analysis is needed to assess the running performance of AF players deeply.

Fatigue-induced Alterations of the Patellar Tendon in Elite Sprint Track Cyclists.

This study aims to investigate morphological and mechanical properties and echogenicity of the patellar tendon (PT) after acute fatigue-induced alterations in sprint track cyclists. Fourteen elite track cyclists participated in this study. The exercise protocol consisted of three maximal start accelerations (over a distance of 62.5 m), one maximal start acceleration (at both 125 m and 250 m), and sprints from the standing start. Immediately after testing all measurements, PT stiffness and thickness were set at 5-10-15-20 mm distal from the apex of the patella and 5-10 mm proximal to the tibial tuberosity. CSA was set at proximal, middle, and distal, while echogenicity was at proximal and distal points. The results showed significant increases in PT stiffness at all reference points after start acceleration (p<0.001). PT thickness showed similar results for stiffness, except for location placed at TT-5 (p<0.001). CSA increased significantly in proximal, middle, and distal regions (p<0.001), while echogenicity of the tendon increased in proximal and distal regions (p<0.001) after start acceleration. Regional-dependent alterations of PT thickness and stiffness may be related to anatomical and physiological mechanisms due to acute isometric contraction in the initial phase of standing start. Tendon echogenicity might be also useful in monitoring tendon mechanical properties and defining acute fatigue-induced changes.

Functional and morphological changes in shoulder girdle muscles after repeated climbing exercise.

This study aimed to investigate the acute effect of repeated climbing actions on functional and morphological measures of the shoulder girdle. Fifteen male indoor climbers participated in this study. All the climbers declared route level 6a+, as the best climbing grade (French climbing grade scale). Functional (range of motion - ROM and muscle strength), and morphological measurements (muscle/tendon stiffness and thickness) after a repeated climbing exercise protocol were analysed. The ROM and muscle strength showed significant decreases from baseline to Immediate-Post (IA) as well as significant increases from IA to 1 h-Post for all movements (p ≤ .001 for all). Muscle stiffness showed significant increases from baseline to IA after as well as significant decreases from IA to 1 h-Post for all muscles (p ≤ .001 for all). However, the thickness showed significant increases from baseline to IA for supraspinatus tendon and muscle thickness and occupation ratio (p ≤ .001 for all), while a significant decrease was observed in acromiohumeral distance (p ≤ .001). Significant decreases from IA to 1 h-Post were found for muscles/tendons and occupation ratio (p ≤ .001 for all), while a significant increase for AHD (p ≤ .001). Our data demonstrated acute alterations in tendon thickness due to acute signs of implement symptom in climbers.

Stiffness and thickness of the upper trapezius muscle increase after repeated climbing bouts in male climbers.

Background: Indoor climbing involves overloading the shoulder girdle, including the rotator cuff and upper trapezius muscles. This on the field study aimed to investigate the effects of repeated climbing bouts on morphological and mechanical measures of the upper trapezius muscle. Materials and Methods: Fifteen experienced male climbers participated in the study. Rate of perceived exertion (RPE), blood lactate concentration ([La-]b), and stiffness and thickness over four points of the upper trapezius were assessed before and after a repeated climbing exercise. The procedure for the climbing exercise consisted of five climbs for a total time of 5-minutes per climb, followed by a 5-minute rest. Results: The analysis showed an increase from baseline to after the 3rd climb (p ≤ 0.01) for RPE and after the 5th climb for [La-]b (p ≤ 0.001). Muscle stiffness and thickness increased at all points (1-2-3-4) after the 5th climb (p ≤ 0.01). We found spatial heterogeneity in muscle stiffness and thickness; muscle stiffness was the highest at Point 4 (p ≤ 0.01), while muscle thickness reached the highest values at points 1-2 (both p ≤ 0.01). Moreover, the analysis between the dominant and non-dominant shoulder showed greater stiffness after the 1st climb at Point 1 (p = 0.004) and after the 5th climb at Point 4 (p ≤ 0.001). Conclusions: For muscle thickness, the analysis showed significant changes in time and location between the dominant and the non-dominant shoulder. Bilateral increases in upper trapezius muscle stiffness and thickness, with simultaneous increases in RPE and blood lactate in response to consecutive climbs eliciting fatigue.

Testing the effects of 4-week training programs based on extreme and medium-sided soccer games: a study focusing on change-of-direction, vertical jump height and locomotor profile.

AIM: This study tested the effects of two training programs (one program based on extreme sided-games of 1v1 vs. one program based on the medium-sided game of 5v5) on the physical fitness adaptations of youth soccer players. In specific, it was analyzed the effects of the training programs on the 5-0-5 change-of-direction time (5-0-5 time), countermovement jump (CMJ), and final velocity in the 30-15 Intermittent Fitness test (VIFT). METHODS: This study followed a randomized parallel study design. Twenty male regional-level soccer players (age: 17.0 ± 0.3 years old) were randomly assigned to two groups: (1) the 1v1 format; and (2) the 5v5 format. The training intervention lasted four weeks. The week before (baseline) and the week after the intervention, the participants were assessed in the 5-0-5 change-of-direction test (measured using timing gates), CMJ (measured by photoelectric cells), and 30-15 Intermittent Fitness test. The training intervention consisted of 8 sessions (2 sessions per week). The 1v1 group performed four repetitions of 30 s in each session, while the 5v5 group performed four repetitions of 4 min. RESULTS: The 5-0-5 time changed - 4.82% (p = 0.004; d = 1.115) for the 1v1 group and - 4.26% (p = 0.004; d = 0.859) for the 5v5 group. CMJ changes occurred both in the 1v1 and 5v5 group and amounted to 1.7% (p = 0.003; d = 0.509) and 1.2% (p = 0.263; d = 0.155) respectively. VIFT changed 2.6% (p = 0.718; d = 0.178) for the 1v1 group and 3.0% (p = 0.593; d = 0.274) for the 5v5 group. The 1v1 group reported significantly lower post-intervention 5-0-5 time than the 5v5 group (- 4.3%; p = 0.048; d = 0.954), although no significant differences in CMJ (3.2%; p = 0.147; d = 0.678) and VIFT (2.5%; p = 0.697; d = 0.177) were revealed. CONCLUSIONS: The extreme-sided games meaningfully beneficiated the vertical jump height and change-of-direction performance of youth soccer players. The extreme-sided games seem more beneficial than medium-sided games for improving these physical abilities while showing that four weeks were enough to impact the players significantly.

Physiological and locomotor demands during small-sided games are related to match demands and physical fitness? A study conducted on youth soccer players.

AIM: The purpose of the study was: (i) to analyze the relationships of physiological and locomotor demands between small-sided games (3v3 and 5v5) and official matches (11v11); (ii) to analyze the relationships between small-sided games demands and the physical fitness of youth soccer players. METHODS: The observational study lasted three weeks. In the first week participants performed the 5v5 (50 × 31 and 40 × 25 m) repeatedly over four days. In the third week they repeatedly performed the 3v3 (39 × 24 and 32 × 19 m) over four consecutive days. Twenty youth soccer players (age: 16.8 ± 0.41) were tested twice for their final velocity at 30-15 Intermittent Fitness test (VIFT), peak speed attained at 30-m sprint test (peak speed), and anaerobic speed reserve (ASR). The heart rate responses and locomotor demands were monitored in the SSGs (3v3 and 5v5) and matches (11v11) occurring once a week. The Polar Team Pro was used as the instrument to monitor heart rate and locomotor demands. Three official matches were also monitored during the period. RESULTS: Results revealed no significant correlations (p > 0.05) between small-sided games and match physiological or locomotor demands. However, VIFT and ASR were significantly correlated with distance covered at 5v5 (r = 0.483; p = 0.031; and r = - 0.474; p = 0.035, respectively), average speed (r = 0.474; p = 0.035; and r = - 0.453; p = 0.045, respectively), while VIFT was also significantly correlated with distance covered at Z2 intensity (r = 0.510; p = 0.022). CONCLUSIONS: The results suggest that the physiological and locomotor demands occurring in small-sided games are significantly different from those occurring in official matches. Thus, physiological and locomotor similarities between small-sided games and official matches are scarce. Considering the second purpose of this study, the results suggest that VIFT and ASR are important physical fitness parameters to modulate the amount of distance covered by the players in 5v5, the average pace, and also the distance covered at high intensities.

Ultrasound imaging of patellar tendon thickness in elite sprint track cyclists and elite soccer players: An intra-rater and inter-rater reliability study.

The goal of our study was to investigate the relative and absolute intra-rater and inter-rater reliability of ultrasound assessment of patellar tendon (PT) thickness assessed over four locations, in track cyclists and soccer players. Fifteen male elite track cyclists and 15 male elite soccer players participated. Tendon thickness was measured over 4 locations placed at 5-10-15-20 mm inferior to the apex of the patella by two experienced examiners. Each examiner took two US images for the test measurements with a 10-min rest period. After a 30-min period, the subjects underwent a retest measurements that were also repeated 1-week after. A two-way analysis of variance revealed a significant group x location interaction on PT thickness for Examiner 1 (p = .001, η2 = .81) and Examiner 2 (p = 0.001, η2 = 0.78). Intra-rater reliability ranged from good to excellent (ICC2,k ≥ 0.75), whereas inter-rater reliability was good (ICC2,k ≥ 0.75) in both groups. Ultrasonographic assessment of PT was found to be a reliable method to assess tendon thickness. The middle location of the PT (corresponding to 15 and 20 mm) can be considered the most reliable spot to measure PT thickness. The PT thickness was larger among track cyclists than soccer players, with larger differences over the distal location (15 mm). Ultrasonographic assessment of PT was found to be a reliable method to assess tendon thickness. The middle location of the PT corresponding to 15 mm and 20 mm can be considered the most reliable area to measure PT thickness.

Gross motor coordination and their relationship with body mass and physical activity level during growth in Children aged 8-11 years old: a longitudinal and allometric approach.

Background: Gross motor coordination (GMC) is fundamental to the harmonious development of physical skills during the growth of children. This research aimed to explore the developmental changes in GMC during childhood, having controlled for the differences in children's body size and shape using a longitudinal, allometric scaling methodology. Methods: A total of 104 children from North-East Italy of third-fourth- and fifth-grade students and each participant were tested for three consequently years. Subjects performed the short version of korperkoordinationstest fur kinder (KTK3) and the anthropometric characteristics were simultaneously collected. The physical activity questionnaire (PAQ-C) was used to evaluate the weekly physical engagement. Results: Ontogenetic multiplicative models suggested nonlinear associations with GMC across the children's developmental years. Linear physique was a significant predictor associated with the development of GMC across time. PAQ-C was significantly associated with GMC from 8 to 13 years old. Conclusion: Growth does not respect linear trends. A greater lean body mass could be assessed as a reliable predictor of GMC in children. The crucial period of life to improve the GMC is 8-10 years, while stabilization becomes evident from 10 to 13 years.

Displacement of Centre of Pressure during Rehabilitation Exercise in Adolescent Idiopathic Scoliosis Patients.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is included into the category of pathologies that could affect postural control. Rarely AIS shows symptoms but often compromises the normal positioning of the head, trunk and, more generally, of the limbs in the space. We used a stabilometric platform to evaluate the motor control outcomes during a self-elongation in girls with AIS. METHODS: In 10 girls with AIS, we evaluated the center of pressure (COP) modifications on a baropodometric platform in a standing position and after a self-elongation correction. RESULTS: All the outcomes (except the eccentricity) showed an increasement during the self-elongation exercise even if the significant differences were not found. CONCLUSION: SE correction contributes to ameliorate the COP symmetry with a better repercussion on the balance management. This highlights the importance of repetitions during all activities of daily life.

Electromyographic Evaluation of the Shoulder Muscle after a Fatiguing Isokinetic Protocol in Recreational Overhead Athletes.

The goal of our study was to examine the muscle activity of the shoulder girdle after isokinetic fatigue, which may simulate muscle activities commonly occurring during specific sport-related activities in recreational overhead asymptomatic athletes. We hypothesized that exercise-induced fatigue, reported after isokinetic protocols, may cause a decrease in the median frequency (MF) of the upper trapezius (UT), infraspinatus (IS), and deltoid muscles. Twenty-four male overhead volleyball (n = 8), handball (n = 8), and tennis (n = 8) athletes participated in this study. All subjects were without shoulder injury history. The surface electromyography (SEMG) was collected on the right (dominant) side of the shoulder girdle muscles in the following order: UT, IS and anterior (DA), and posterior deltoideus (DP). The fatigue protocol consisted of three sets of 32 maximum isokinetic concentric contractions while performing shoulder internal and external rotation at an isokinetic speed of 120 o/s. The resultant difference in median frequency (ΔMF) values consistently dropped after the fatiguing tasks across all recorded muscles, in terms of the initial MF (MFINI = 65.1 ± 1.1 Hz) and final MF (MFFIN = 57.9 ± 0.9 Hz), and the main effect of time was significant (F(1,22) = 43.15, p < 0.001). MF values decreased mostly for IS (ΔMFIS = -9.9 ± 1.6 Hz) and DP (ΔMFPD = -9.5 ± 1.9 Hz) muscles, while DA and UT showed smaller changes (ΔMFDA = -6.9 ± 1.5 Hz) and (ΔMFUT = -3.2 ± 1.3 Hz). The results of our study show a meaningful contribution in determining increased fatigue of the shoulder girdle muscles during repeated isokinetic internal-external rotation protocols. We have also demonstrated a significant decrease in MF in all examined muscles, especially IS and DA.

Allometric association between physical fitness test results, body size/shape, biological maturity, and time spent playing sports in adolescents.

Regular participation in strength and conditioning activities positively correlates with health-related benefits in sports (team and individual). Maturity offset (MO) is a recognized parameter in fitness outcome assessment. The aims of the present study are to analyze cross-sectional allometric development of motor performances in a sample of adolescents and relate scaled motor performance to the estimated amount and type of physical activity and biological maturity status in 771 subjects aged 14-19 years. Three physical fitness components were evaluated using field tests (standing broad jump, sit-ups, shuttle run). Extra hours of sport after school (EHS) and MO were the covariates. The model to predict the physical performance variables was: Y = a · Mk1 · Hk2 · WCk3 · exp(b · EHS + c · MO) · ε. Results suggest that having controlled for body size and body shape, performing EHS and being an early developer (identified by a positive MO slope parameter) benefits children in physical fitness and motor performance tasks.

Working memory network plasticity after exercise intervention detected by task and resting-state functional MRI.

The current study examined the effects of an 11-week exercise intervention on brain activity during a working memory (WM) task and resting-state functional network connectivity in deaf children. Twenty-six deaf children were randomly assigned to either an 11-week exercise intervention or control conditions. Before and after the exercise intervention, all participants were scanned with functional magnetic resonance imaging (fMRI) during N-back task performance and a resting state. The behavioural results showed that the exercise intervention improved WM performance. Task activation analyses showed an increase in the parietal, occipital, and temporal gyri and hippocampus and hippocampus (HIP). In addition, WM performance improvements were associated with greater activation in the left HIP region. Resting-state functional connectivity (Rs-FC) between HIP and certain other brain areas shown a significant interaction of group (exercise versus no exercise) and time (pre- and postintervention). Moreover, connectivity between the left HIP and left middle frontal gyrus was related to improved WM performance. These data extend current knowledge by indicating that an exercise intervention can improve WM in deaf children, and these enhancements may be related to the WM network plasticity changes induced by exercise.

Quadriceps and Patellar Tendon Thickness and Stiffness in Elite Track Cyclists: An Ultrasonographic and Myotonometric Evaluation.

Track cyclists are required to perform short- and long-term efforts during sprint and endurance race events, respectively. The 200 m flying sprint races require maximal power output and anaerobic capacity, while the 4,000 m pursuit cyclists demand a high level of aerobic capacity. Our goal was to investigate spatial changes in morphological and mechanical properties displayed using 3D topographical maps of the quadriceps muscle and tendons after 200 m flying start and 4,000 m individual pursuit race in elite track cyclists. We hypothesized a non-uniform distribution of the changes in the quadriceps muscle stiffness (QMstiff), and acute alterations in quadriceps tendon (QTthick) and patellar tendon (PTthick) thickness. Fifteen men elite sprint and 15 elite men endurance track cyclists participated. Sprint track cyclists participated in a 200 m flying start, while endurance track cyclists in 4,000 m individual pursuit. Outcomes including QTthick (5-10-15 mm proximal to the upper edge of the patella), PTthick (5-10-15-20 mm inferior to the apex of the patella)-using ultrasonography evaluation, QMstiff, and quadriceps tendon stiffness (QTstiff) were measured according to anatomically defined locations (point 1-8) and patellar tendon stiffness (PTstiff)-using myotonometry, measured in a midway point between the patella distal and the tuberosity of tibial. All parameters were assessed before and after (up to 5 min) the 200 m or 4,000 m events. Sprint track cyclists had significantly larger QTthick and PTthick than endurance track cyclists. Post-hoc analysis showed significant spatial differences in QMstiff between rectus femoris, vastus lateralis, and vastus medialis in sprint track cyclists. At before race, sprint track cyclists presented significantly higher mean QTthick and PTthick, and higher QMstiff and the QTstiff, as compared with the endurance track cyclists. The observed changes in PTThick and QTThick were mostly related to adaptation-based vascularity and hypertrophy processes. The current study suggests that assessments using both ultrasonography and myotonometry provides crucial information about tendons and muscles properties and their acute adaptation to exercise. Higher stiffness in sprint compared with endurance track cyclists at baseline seems to highlight alterations in mechanical properties of the tendon and muscle that could lead to overuse injuries.