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COUNTERMOVEMENT JUMP PERFORMANCE VARIABLES CORRELATE WITH WEIGHTLIFTING PERFORMANCE IN ELITE PARTICIPANTS
Full text linkIt is valuable to monitor athletes’ training efficacy to better guide their conditioning and performance programs. In weightlifting, assessing 1RM routinely may require longer recovery and limit training. The purpose of this study was to identify associations between 1RM weightlifting performance and variables calculated from a maximal countermovement jump (CMJ). Force data were collected and variables calculated for seven elite weightlifters during CMJs. Maximum rate-of-force development (RFD) during the countermovement jump was associated with both Snatch (r^2 0.56, p=0.05) and Clean & Jerk (C&J) (r^2=0.49, p=0.08) performance. Eccentric time (r^2=0.55, p=0.06) and ecc-conc ratio (r^2=0.68, p=0.02) were correlated with C&J performance only. CMJ variables may provide expedient efficient feedback on athlete performance and conditioning in this sport
Frequent Use of Contingency Management and Opioid Treatment Programs that Provide Treatment for More than Only Opioid Use Disorder
Full text linkContingency management is an effective behavioral intervention for treating substance use disorders that provides patients with incentives for objective verification of completed targeted recovery behaviors including abstinence from substances, attending treatment, and medication adherence. Accredited/licensed opioid treatment programs provide effective, medications for opioid use disorder. This study evaluated the prevalence of frequent contingency management use among a national sample of opioid treatment programs in the U.S. (N= 672). A binary logistic regression model examined factors associated with providing contingency management, including state-level fatal overdoses, number of pharmacotherapies, outpatient treatment, facility ownership, and residential treatment. Most evaluated facilities provided contingency management (n=440; 65.5%). Facilities that prescribed more pharmacotherapies, were located in states with high drug overdose death rates, and for-profit (compared to nonprofit) providers were more likely to offer contingency management. Because contingency management effectively treats substance use disorders, contingency management should be offered more broadly across opioid treatment program
EFFECTS OF FREEDIVING FIN PARAMETERS ON ANKLE STRESS USING 3DIVE (FREE DIVING VALGUS EXPERIMENT) RIG
Full text linkThe aim was to investigate the impact of freediving fin parameter on the diver for two different foot morphologies, one without deformation and other with a hallux valgus. It proposes to identify the parameters that have the greatest influence on the stresses applied to the ankle. A complete experimental design with 4 factors was set up. The factors studied were the length of the fin, the stiffness, the water channelling system and the angle between the blade and the liner. A prosthetic foot was used to realise reproducible test in pool. It was fitted with strain gauge at the ankle. 16 fins were tested for the two-foot morphologies. ANOVA test were used to discriminate the most influential parameters and define if they are the same for both morphologies. The most influential factor was the angle between the liner and the blade (
THE EFFECT OF FOOTWEAR FIT ON MOVEMENT COMPLEXITY IN TRAIL RUNNING
Full text linkIn trail running athletes must adapt their movement patterns to navigate obstacles in their path. Sample entropy is a method to evaluate an athlete’s flexibility to alter their movement from stride to stride. The purpose of this study was to examine the effects of running speed, duration, terrain, sex, and footwear on movement complexity in trail runners. Thirty trail runners (15 female) ran a trail loop in two shoes: a lace shoe and a wrap shoe. We used linear mixed effects models to examine the effects of independent variables on sample entropy of foot accelerations. More technical terrain, faster running speed, being early in the run (vs. the end of the run), female sex and the wrap shoe were associated with greater complexity. A wrap shoe designed to better conform to the foot may offer improvements in movement complexity associated with better running performance and absence of injury
CHANGES IN ROWING ERGOMETER TECHNIQUE AND POWER OUTPUT AFTER A SPECIFIC CORE TRAINING PROGRAM
Full text linkThe purpose of this study was to evaluate the changes in core stability, core strength, ergometer rowing technique and power output after a a specific core training program. 13 young rowers followed an 8-week training program consisting of 20min additional training realized 4 to 5 times a week composed of low load core stability, high load dynamic strength and ergometer specific exercises. After the program, rowers’ global core stability was improved (p=0.003), but not trunk maximal isometric strength. Ergometer rowing tests showed significant improvement of trunk technique (higher mean to peak power and work ratio, lower trunk negative power) and trunk power (+35W) at 20spm but only for trunk technique at a competitive stroke rate. This training program could be considered by the rowers and trainers to develop sport-specific core capacity to produce and transfer power
RACKET HOLDING FORCES FOR PLAYING A FOREHAND STROKE AT VARIED SWING SPEEDS IN TABLE TENNIS
Full text linkThe purpose of this study was to investigate racket gripping forces in table tennis when 9 experienced players struck a ball at different swing speeds with a forehand stroke. Handle grip force, and paddle pressing forces by the index finger and thumb, and racket swing speed were measured using a sensor racket developed, and a motion capture system. The handle grip force exhibited peaks before and after the ball impact. The peak handle forces increased with swing speed non-linearly. In the fast drive stroke, the pre-impact peak of the grip force summed for the handle and fingers reached on average of 85 N with a range of 30 N to 135 N. This large individual variability was considered a reflection of differences in racket handling skills acquired in long-term training under different coaches
GENDER DIFFERENCES IN MUSCLE CONTRACTION AND CO-CONTRACTION ACTIVITIES DURING THE IMPACT PHASE OF SINGLE-LEG LANDING TASK IN BADMINTON
Full text linkOur study aimed to explore ACL injury risk factors in females versus males during badminton single-leg landings. Sixteen players (8 male, 8 female) participated, with lower limb kinematics, ground reaction forces, and muscle activity measured using motion capture, force plates, and electromyography (EMG). Independent samples t-test analyzed gender differences in leg kinematics, mean normalized leg muscle activation (MVC%), and muscle co-contraction post-landing. Females, compared to males, exhibited higher rectus femoris, medial hamstring, and gastrocnemius muscle activity during the post-landing phase. Additionally, males had a higher co-contraction ratio in the medial and lateral gastrocnemius than females. Female badminton players\u27 neuromuscular control strategies may lack ACL protection, posing a potential risk for higher ACL injury incidence
PATTERN MATCHING ANALYSIS OF LOWER-LIMB GAIT MOTION IN WATER AND ON LAND AND ITS RELATIONSHIP TO JOINT MOTION
Full text linkThis study applied dynamic time warping (DTW) to lower-limb gait motion in water with a slow to fast pace compared with those on land at a comfortable pace; this was done for 15 participants to examine if the result obtained would be similar to previous study irrespective of gait pace in water. The correlation between the DTW results and the joint angle difference in the two environments was also investigated to clear the reason for the result of DTW. Consequently, DTW detected incomplete motion in the water at any pace in the hip joint just before the toe-off, which moderately correlated (r = 0.59) with the peak extension angle difference of the hip joint between the two environments. Therefore, an increasing extension motion in the hip joint just before the toe-off during gait in the water would be suggested for simulating gait motion on land
ANALYSIS OF KINEMATICS DURING SPRINT RUNNING AND DIFFERENT TYPES OF JUMPS
Full text linkThis study aimed to compare sprint running and various horizontal jumps in terms of speed and step kinematics, focusing on speed versus distance and their relationship with maximal running speed. Twelve female sprinters performed sprints, single-leg jumps for distance and speed, and bounding for distance and speed. The findings showed significant differences in kinematics between sprinting and jumping. Positive correlations were found between sprint speed and single-leg jump speed and distance, step length in all jumps, and contact and flight time in some. No significant correlation was found between sprint speed and step frequency in the jumps. Bounding for speed closely resembled sprint running in kinematic parameters but had only weak to moderate correlation, whereas speed during single-leg jumps had the highest correlation with running speed
WHOLE-BODY COORDINATIVE STRATEGIES CONTRIBUTE TO THE MINIMIZATION OF CENTRE OF MASS DISPLACEMENT IN MAXIMAL VELOCITY SPRINTING
Full text linkSprinting is a dynamic skill that requires rapid and precise postural control. This study investigates the association between frontal plane centre of mass (CoM) displacement, whole-body coordination, and sprint velocity. Significant correlations with sprint velocity were found between stance phase frontal plane (cPL), superior inferior range of motion (SI ROM), and sprint velocity. Spatiotemporal coordinative coupling of the bilateral knees and thorax-pelvis axial twisting displayed significant partial correlations with the minimization of frontal plane cPL and SI CoM RoM. The findings of this work suggest that both the upper and lower body contribute to the control of the CoM within the frontal plane. Coaches and performance practitioners can leverage these findings to identify potential technical errors to enhance athlete sprint performance