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TRUNK POSTERIOR PULLING PERTURBATION INCREASED VARIABLES ASSOCIATED WITH ACL LOADING DURING LANDING
Get PDFThe purpose of this study was to identify the effects of posterior pulling perturbation applied to the upper or lower trunk on variables associated with anterior cruciate ligament (ACL) loading during landing. Thirty-eight participants performed double-leg vertical jumps with and without posterior pulling perturbation applied to the upper/lower trunk shortly after the peak jump height. Perturbation resulted in significantly greater impact forces, smaller knee flexion angles, and greater knee extension and adduction moments compared to no perturbation. Upper trunk perturbation resulted in smaller trunk flexion angles than the lower trunk perturbation location. Mid-flight posterior pulling perturbation applied to upper and lower trunks increased ACL loading variables during landing. Posterior pulling perturbation or anterior pushing perturbation might be involved in training to decrease ACL injury risk
NOVEL STRENGTH TRAINING TARGETING MEDIAL QUADRICEPS/HAMSTRING CAN ALTER THE BIOMECHANICAL RISK FACTORS FOR ACL INJURY
Get PDFThe purpose of this study was to examine the effects of strength training targeting the medial thigh muscles on knee joint kinematics, kinetics, and muscle activation during single-leg landing. Eighteen healthy participants conducted exercises targeting medial thigh muscles for 8 weeks. Three-dimensional knee joint kinematics/kinetics and muscle activity of lower extremity were obtained before and after training. Two-tailed paired t-tests were performed at a significance level of 0.05. As the results, there were decreased varus-valgus excursion (p=0.011) and peak valgus moment (p=0.029), but increased gluteus medius activation (p=0.020) and vastus medialis-to-vastus lateralis co-activation ratio (p=0.011) after training. In conclusion, strength training targeting medial thigh muscles can modify the biomechanics associated with anterior cruciate ligament injuries
APPLICATION OF QUALITATIVE MOVEMENT DIAGNOSIS ON SPRINT START
Get PDFThe purpose of this study was to examine the effect of applying Qualitative Movement Diagnosis (QMD) on sprint start performance. Twelve NCAA II sprinters volunteered for this cross-sectional study. The steps of applying QMD in sprint start performance were introduced. Subjects were asked to perform three pre-intervention trials of block starts in their preferred setting. The block setting and joint kinematics at knee and hip from both sides of body were evaluated. The feedback was provided for the three post-intervention trials. A moderate effect of significant improvement of exist velocity (p = 0.04) was observed as well as lead leg hip angle (p = 0.004), rear leg knee angle (p = 0.001), and block spacing (p \u3c 0.001). QMD, which consists of preparation, observation, evaluation/diagnosis, and intervention, can be used to effectively change and improve sprint start performance
REAL-TIME BIOFEEDBACK TO CONTROL TRUNK POWER PRODUCTION IN ERGOMETER ROWING
Get PDFThe purpose of this study was to test a real-time feedback for ergometer rowing based on parameters describing a rower’s technique, specifically the curve of the power produced by the trunk. The goal was to enhance the trunk engagement during the drive phase. Eleven rowers performed an ergometer rowing session at 20spm and maximum intensity, where their habitual technique was measured. Then, they performed six sessions of 3min with feedback exposure on trunk time to peak power and work ratio. On average, rowers were able to advance their trunk power production within the drive phase by 1.3%, but without significant effect on performance, despite a mean 43W increase in trunk power. Feedbacks of this kind could be used in training to address specific parameters of a rower’s technique
THE RELATIONSHIPS OF FUNCTIONAL MOBILITY WITH MUSCLE STRENGTH AND PROPRIOCEPTION AMONG OLDER ADULTS
Get PDFFunctional mobility impairment is the most common risk factor for falls among older adults, with three potential factors (muscle strength, tactile sensation, and proprioception) being responsible for their functional mobility. This study aims to compare functional mobility and the three factors, and investigate their relationships among older adults of different ages. One hundred sixty-six participants were categorized into younger (YG), middle (MG), or older (OG) aged groups. The OG has worse functional mobility, muscle strength, tactile sensation, and proprioception than YG and MG. In the YG and MG groups, both proprioception and muscle strength showed correlations with functional mobility. In the MG, only muscle strength demonstrated a correlation with functional mobility. Rehabilitation and exercise are recommended to improve proprioception and prevent falls in older adults
EXPLORING THE PERFORMANCE – ACL INJURY RISK CONFLICT DURING ANTICIPATED AND UNANTICIPATED SIDESTEPPING TASKS
Get PDFThe aims of this study were i) to determine if performing regression models with high-risk datasets compared to full datasets could help to understand better which biomechanical variables could really be considered ‘at-risk’ and/or ‘better for performance’ and ii) to determine the effect of anticipation on ‘at-risk’ biomechanical variables. Basketball players (n=33) completed 6 changes of direction in anticipated or unanticipated conditions. Kinematics, dynamics and performance were measured with motion capture and force plates. A lower number of predictors were found for high-risk dataset compared to full dataset. Hip adduction and trunk lateral lean could be both considered ‘at-risk’ and ‘better for performance’. Moreover, anticipation impacts the “at-risk” technique, so training instructions should differ between anticipated and unanticipated sidestepping tasks
DEVELOPMENT AND RECOMMENDATION OF KINEMATIC EVENT DETECTION METHODS FOR USE DURING BEND SPRINT RUNNING
Get PDFThis study aimed to validate different kinematic event detection methods for use during maximal velocity bend sprint running. Eight sprinters completed nine 60 m bend sprints each around an athletic track with a 36.5 m bend radius. Three kinematic event detection methods were adapted and compared to instances of touchdown and toe-off as determined by force plates. Using peak and maximum vertical acceleration of the toe marker yielded mean errors of less than 1 frame (0.004 s) for touchdown, whilst peak acceleration was the most accurate for determining toe off (mean error = 0.85 frame).The findings suggest that, when carefully applied with additional controls, kinematic-based event detection methods offer an accurate alternative to force-plate detection methods for use during biomechanical analyses of bend sprint running when ground reaction force data are not available
IMPACT OF FOOTWEAR BENDING STIFFNESS AND TORSIONAL STIFFNESS ON ANKLE BIOMECHANICS DURING HANDBALL SPECIFIC FAKE-AND-CUT MANOEUVRES
Get PDFIn this study, the impact of footwear bending stiffness on ankle and foot biomechanics during indoor fake-and-cut manoeuvres was investigated. Footwear, along with torsional and bending stiffness, are hypothesized to influence the risk of ankle sprain injury. In this study, a mobile, pneumatically driven cantilever rig was used to quantify these footwear characteristics. Following this, participants executed fake-and-cut movements wearing their habitual footwear, while motion capture and force plate data were recorded. Utilizing machine learning clustering algorithms, participants were grouped based on their footwear stiffness. Subsequent SPM analysis revealed lower forefoot dorsiflexion and increased forefoot inversion in the stiff group. These findings underscore the need for further research on the interaction between shoe properties and injury risk indicators
DIFFERENCES IN MUSCLE DEMAND ACROSS TAKE-OFF TECHNIQUES IN THE BACK HANDSPRING STEP OUT IN WOMEN’S GYMNASTICS
Get PDFThe back handspring step out (BHS) is a foundational skill in balance beam routines that can be performed using three different take-off techniques (Simultaneous Flexion, Sequential Flexion, Double-Bounce). However, it is unclear if the different techniques require different levels of muscle demand. The purpose of this study was to use modelling and simulation to quantify muscle demand across the three techniques. While there were no differences in total average muscle demand between techniques, the Sequential Flexion technique required more demand from the knee and hip flexors, while the Simultaneous Flexion and Double-Bounce techniques required more demand from the knee and hip extensors. Thus, gymnasts using each of these techniques should target these specific muscle groups for increased strength and power
MASTERFUL DEFENSE VS. ROOKIE FUMBLES: HOW DO EXPERT AIR HOCKEY CHAMPS ON MOBILE REVEAL THEIR SKILLS THROUGH POSTURE AND TOUCH?
Get PDFWe explored the relationships between expertise, in-game performance, posture, and screen interactions in mobile sports games. Twenty participants (10 experienced) played Disc-O, a turn-based air hockey game. Posture, phone holding style, play style, and screen metrics (displacement, velocity, touch size, pressure, and time to action) were compared. No significant associations were found between experience or performance and handedness, posture, holding style, or play style (p \u3e 0.05). Experienced players performed better (p = 0.02) but showed no significant screen interaction differences compared to novices (p \u3e 0.05). They reacted faster, with victors having smaller touch points, suggesting more precise motor control and efficient decision-making. The lack of posture and holding style differences suggests adaptability and potential for training interventions