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EXAMINING THE SEQUENCING OF JOINT VELOCITIES DURING TENNIS SERVES
Get PDFThis study examined the sequencing of the euclidian joint velocity and joint angular velocity when performing the tennis serve at the individual level. 10 International level players (male and female) performed 40 maximum serves to 4 target locations. A motion capture system recorded the kinematics of the service action (200 Hz). A descriptive analysis demonstrated sequencing of the euclidian joint velocity and the joint angular velocity, changed as a function of service position. The results showed the same pattern from the highest to lowest order: peak wrist, elbow, shoulder, and hip for the euclidian joint velocity and joint angular velocity, which underlines the sequencing is similar between the two frames of reference, and that the wrist movement is key in serving across all participants and conditions. The study provides insights into individual biomechanical patterns during serving, emphasizing the importance of joint-specific dynamics for optimizing sports performance
EXPLORING KNEE BIOMECHANICS IN DEFENSIVE SPORTS: A COMPARATIVE STUDY OF FORWARD AND BACKPEDAL SIDESTEP CUTS WITH AND WITHOUT A KNEE BRACE
Get PDFCutting, a key movement in dynamic sports, is associated with increased anterior cruciate ligament injuries. The influence of knee braces, commonly used for injury prevention, on knee mechanics requires further analysis. The purpose of this study was to examine the impact of knee braces on knee biomechanics during forward and backpedal cutting. Ten healthy males performed forward and backpedal cutting tasks, with and without a dual-hinged brace, simulating offensive and defensive movements. Compared to forward cuts, backpedal cuts showed increased knee flexion and decreased abduction and internal rotation. Knee internal extension moments and adduction moments increased, while knee internal rotation moments decreased during the backward cut. The lack of significant effect from knee braces highlights the need for continued research to aid in developing injury prevention strategies for athletes
EFFECTS OF HABITUAL FOOT STRIKE PATTERNS ON ANKLE MUSCLES ACTIVATION DURING RUNNING
Get PDFThis study aimed to determine differences in muscle activation between habitual rearfoot strike pattern (RFS) and non-rearfoot strike pattern (NRFS) runners. Ten habitual RFS and ten habitual NRFS runners were recruited in this study. The electromyography signals were collected from the tibialis anterior, soleus, medial and lateral gastrocnemius muscles at 9 km/h running. The root mean square of each muscle and the co-activation of ankle flexors and extensors (COAnkle) were calculated. Independent t-tests or nonparametric tests were used to examine the differences between two groups. The results showed that during the pre-activation and swing phases, the COAnkle of RFS runners were greater than those of NRFS runners. This suggested that RFS runners with higher COAnkle at pre-activation might be a strategy in response to great impact force during the early of stance
PLANTAR PRESSURE DIFFERENCES BETWEEN LOW-RISK AND HIGH-RISK KNEE OSTEOARTHRITIS RUNNERS: A PRELIMINARY STUDY
Get PDFLittle is known about the biomechanical factors that predate knee osteoarthritis (OA) for high-risk recreational participants. This study aims to investigate if plantar pressure differences exist between low and high-risk knee OA runners. Fifteen male recreational runners participated in a preliminary study and were divided into low-risk (N = 8) and high-risk (N = 7) knee OA groups. Both groups ran 100 metres thrice in both indoor and outdoor settings at a comfortable pace. Participants’ plantar pressure was measured. No significant differences in plantar pressure between low-risk and high-risk knee OA runners were found. Future studies may consider employing a better representation of high-risk knee OA runners and use radiographic techniques for a more accurate classification
COMPARISON BETWEEN OUTCOMES OF A SPRINT TEST ON A WHEELCHAIR ERGOMETER AND ON-COURT AMONG WHEELCHAIR TENNIS PLAYERS
Get PDFThe current study compared a wheelchair sprint in the laboratory (lab) on a wheelchair ergometer with a wheelchair sprint on-court in a group of experienced wheelchair tennis players. Nine wheelchair tennis players performed a 10m sprint in the lab, on a computerized wheelchair ergometer, and a 10m sprint on-court, equipped with inertial measurement units. Test duration, mean power output and mean velocity showed no differences between lab and field sprints, peak velocity was consistently higher in the field sprint. Despite methodological differences and experienced rolling resistance between the lab and field sprint, test duration, achieved power output and mean velocity did not differ. Field sprint testing is easier to conduct and provides valuable insights, and lab testing gives a broad additional array of in-depth biomechanical analyses
BICEP FEMORIS MUSCLE STATES PRIOR TO AND DURING A HAMSTRING STRAIN INJURY WHILST SPRINTING
Get PDFKinematic and kinetic data from a maximal velocity sprint trial resulting in a hamstring strain injury was analysed using a forward dynamics musculoskeletal model solved using direct collocation (OpenSim Moco) to assess muscle fibre states of the bicep femoris long head (BFlh) muscle during the swing phase. During the injury trial, the BFlh showed greater peak fibre lengths, similar peak fibre force, velocity and power, but less negative work compared to submaximal speeds. Accumulation of muscle tissue damage from previous steps and prior submaximal sprints due to the eccentric demand on the muscle could have resulted in the BFlh failing as it no longer had the capacity to withstand load
OPENSIM FULL-BODY MODEL FOR ATHLETES WITH A RUNNING-SPECIFIC BELOW THE KNEE PROSTHESIS
Get PDFTo date, there is no comprehensive open-source tool to provide movement analysis of athletes using a running-specific prosthesis (RSP) with a below the knee amputation (BKA) to enable the calculation of corresponding inverse kinematics and dynamics. A combination of physical measurements, 2D imagery, 3D motion capture data and geometrical calculations were used to create a musculoskeletal full-body OpenSim model with subject-specific BKA structures. The model was able to reproduce athlete’s joint angles and joint moments of the lower extremities while allowing for movement comparison to non-amputee athletes. The model provides a motion analysis tool for athletes with a RSP in an open-source environment, providing qualitatively similar results to previous research, and lays the foundation for more insights into BKA athletes’ muscle activity and acting muscle forces
THE ENERGY TRANSFERRED BETWEEN LOWER-BODY SEGMENTS BY SUCCESSFUL AND LESS SUCCESSFUL MALE RUGBY PLACE KICKERS
Get PDFThe purpose of this study was to understand how energy is transferred during a rugby place kick and how it differs between successful and less successful kickers. Senior male kickers (n=33) performed maximal range place kicks which were analysed using 3D motion capture (240 Hz), enabling segment powers to be determined. Energy was transferred out of the support leg throughout the backswing and early downswing, adding to the energy at the pelvis, which was subsequently transferred out as the kick knee extended towards the ball. Kickers who were limited by range, transferred less energy out of the support leg and into their kick foot, likely leading to a reduced kick foot and therefore, ball velocity. Appropriate support leg action appears important for achieving greater range in rugby place kicking
EVALUATING THE EFFECTIVENESS OF SPORTS BRAS DURING TREADMILL RUNNING THROUGH DISCRETE AND CONTINUOUS MEASURES OF BREAST KINEMATICS
Get PDFThis study aimed to compare discrete and continuous breast kinematics and assess their relationship with perceived breast pain and support. Breast motion was assessed as relative nipple position, velocity and acceleration for 36 females during treadmill running. Statistical parametric mapping identified where and for how long across the gait cycle sports bras were effective at reducing breast movement. Superior-inferior range of motion (r=0.86) was most closely associated with perceived breast support; breast pain was most closely associated with anterior-posterior peak (-) acceleration (r=0.7). Continuous analysis of breast movement can identify when in a gait cycle breast movement significantly differs between breast support conditions. Discrete measures are more discernible at identifying what variables contribute to feelings of breast pain and support
MUSCLE STIFFNESS, LENGTH AND RANGE OF MOTION ARE UNCHANGED IN MALES AND FEMALES IN RESPONSE TO AN ACUTE BOUT OF STATIC PECTORAL STRETCHING
Get PDFStretching is common, yet little work has explored the influence of stretch intensity and sex differences in response to stretching. We investigated the acute effect of static pectoral stretching at two intensities (110 and 120%) on pectoralis minor length, horizontal abduction range of motion (HA-ROM), and pectoralis major and minor stiffness using shear wave elastography in males and females. Twenty-four participants (N=24, 12 female; age: 25±4.6) attended two sessions where they received three sets of a randomized stretch for 30s with 30s rest between. There were no differences in pectoralis minor length, HA-ROM, or pectoralis minor or major stiffness between males and females following stretching. These findings suggest that the sexes respond similarly to static pectoral stretching. Further stretching research exploring potential sex-differences with different doses are neede