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EFFECTS OF RUNNING FATIGUE ON KNEE JOINT SYMMETRY AMONG AMATEUR RUNNERS
Get PDFThe purpose of this study was to reveal the effects of running fatigue on the symmetry of lower limb dynamics and kinematics parameters. 18 male amateur runners participated in this study. The marker trajectories and ground reaction forces were collected via an 8-camera VICON and Kistler 3D force platform before and after the running-induced fatigue protocol. Symmetry angles (SA) of joint moments, range of motions (ROM), and joint stiffness in three planes were calculated pre- and post-fatigue. SA of knee Extension Angle, Internal rotation, Abduction moment, coronal ROM and joint stiffness significantly increased after fatigue(
TOWARDS THE DEVELOPMENT OF BENCH TESTING FOR LOWER-LIMB PROSTHETIC SOCKETS FOR SPORT APPLICATIONS
Get PDFProsthetic sockets are the bespoken part of lower-limb prostheses. Knowledge about the mechanical properties of sockets is essential to ensure patient safety and comply with current medical device regulations. This includes sockets designed for sport activities. Unfortunately, the literature is extremely limited and contradictory as described in a recent systematic review. The aim of this study was to initiate a research activity aiming to design a mechanical bench system for socket testing and perform a comparative analysis of the ultimate strength of alternative socket layups. Results highlight substantial differences in the maximum loading at failure, stressing the importance of increasing the knowledge about socket mechanical properties to support prosthetists provide reliable and safe products to patients and athletes
A CASE STUDY OF THE GENERATION OF ANGULAR MOMENTUM AND ANGULAR VELOCITY IN SOMERSAULT BACKWARD STRETCHED WITH 2/1 AND 3/1 TWISTS PERFORMED BY A SINGLE VARSITY MALE GYMNAST
Get PDFThe purpose of this study was to compare the angular momentum and angular velocity in somersault backward stretched with different number of twists performed by a single varsity male gymnast. The 3D motion captured system (Qualisys, 250Hz) was used to collect kinematic data of a single varsity male gymnast A who performed the somersault backward stretched with a double (2/1) and a triple (3/1) twist. The angular momenta and angular velocities of the body segments and whole body were calculated by the Tang’s method. More than a half of the twist angular momentum of the whole body in both 2/1 and 3/1 twists was generated during the take-off phase, which indicated that the gymnast A was classified as a contact twist type. In case of the gymnast A there seemed no difference in angular momenta of 2/1 and 3/1 twists, although he generated the angular momentum of the twist earlier in 3/1 than 2/1. He controlled the number of twists by his body maneuver before landing. Since these findings were obtained from a single gymnast, we need to investigate twist techniques and angular momentum date of various gymnasts
DIFFERENCES IN LOWER LIMB JOINT STIFFNESS IN MULTIPLE MOVEMENTS FOLLOWING ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION
Get PDFAltered lower limb joint kinetics are frequently observed following anterior cruciate ligament reconstruction (ACLR), which may lead to an increased risk of re-injury. The aim of this study was to establish the extent to which joint stiffness differs in a unilateral and bilateral drop jump, and a 90° pre-planned cut following ACLR. A cohort of 127 male patients 8–10 months post-ACLR and 45 non-injured controls took part in the study. Both a unilateral and bilateral drop jump, and a 90° pre-planned cut were completed, while ground reaction forces and three-dimensional kinematics were recorded. ACLR patients had lower knee stiffness for the cut (d=0.192, p=0.040) and the bilateral drop jump (d=0.534,
LONG-TERM WEARING MINIMALIST FOOTWEAR ASSOCIATED WITH BIOMECHANICAL CHANGES DURING WALKING
Get PDFThe aim of this study was to investigate the changes in kinematics and kinetics variables during walking barefoot and minimalist footwear between two different group of experience and nonexperience with minimalist footwear. Participants performed randomly 8 trials in barefoot and minimalist footwear. Statistics analyses were used to determine differences between ankle joint kinematics and kinetics variables defined as
ASSOCIATION BETWEEN T2* RELAXATION TIME AND THE MECHANICAL PARAMETERS OF THE ACHILLES TENDON IN TRAINED AND UNTRAINED POPULATIONS: PRELIMINARY DATA
Get PDFThe purpose of this study was twofold: 1) to investigate the association between T2* relaxation time and Achilles tendon mechanical/material parameters (e.g., stiffness, Young’s modulus and hysteresis); and 2) to check the sensibility of the T2* in determining the differences among population, providing important insight for sports scientist and clinicians. Thirty participants (10 power athletes, 10 endurance athletes and 10 healthy participants) participated in this study. Magnetic resonance imaging (MRI) was used to quantify T2* relaxation time at rest. Ultrasound, kinetics, EMG and kinematics data were used to calculate Achilles tendon mechanical/material parameters during maximum voluntary contractions of the plantar-flexor muscles. Preliminary data on power athletes and healthy controls suggest that the Achilles tendon Young’s was higher in power athletes compared with healthy control, whereas tendon hysteresis and T2* relaxation time were lower in power athletes. Tendon stiffness was similar between populations. Our preliminary data suggest that T2* can be utilised to investigate the differences between the population in terms of material parameters (Young’s modulus and hysteresis) but not in mechanical ones (e.g. stiffness)
A SYSTEMATIC REVIEW OF METHODOLOGIES USED TO ASSESS “UNANTICIPATED” CUTTING MECHANICS
Get PDFBiomechanical analysis of cutting mechanics is a popular approach to assessing risk factors for injuries such as anterior cruciate ligament ruptures. The purpose of this study was to systematically review the methodological approaches to assessing unanticipated cutting mechanics and provide a review of such approaches. A total of 93 articles where identified that had assessed unanticipated cutting. The most common methodological design was a 45° cutting task following a run-up where the direction of the cut was determined by a light-based stimulus. External light stimuli create a worst-case scenario by providing information about the task at the last moment meaning opportunity for preparatory mechanics is limited. However, light stimuli do not allow for perception-action to take place and may therefore not truly reflect an athlete’s cutting mechanics
TECHNIQUE CHANGES ACROSS MAXIMAL AND SUBMAXIMAL INTENSITIES IN FAST BOWLERS: IMPLICATIONS FOR ESTIMATING WORKLOAD
Get PDFThe purpose of this study was to determine which technique characteristics were associated with release speed when bowlers prescribed to maximal and submaximal intensities and compare these to the characteristics associated with the fastest bowlers. Elite and sub-elite, male fast bowlers (n=8) bowled one over each at 60%, 80% and 100% intensity in a randomised order and repeated this across two sessions. When bowling faster, bowlers tended to decrease BFC-FFC duration (R=0.63) and had a higher resultant angular velocity (R=0.59) and acceleration (R=0.55) of the non-bowling arm. Meanwhile, the fastest bowlers tended to have the shortest FFC-BR durations (R=0.66). Both inter- and intra-individual variation in technique should be considered when trying to improve performance or monitoring fast bowling workload across a range of intensities
EFFECTS OF 90-MINUTE MATCH SIMULATION ON WHOLE-BODY DYNAMIC STABILITY IN UNANTICIPATED SIDE CUTTING
Get PDFThe purpose of this investigation was to identify the effects of soccer match-specific physical exertion on deployment of movement strategies to control the centre of mass (CoM) in the medio-lateral direction during unanticipated side cutting. Twenty-one healthy male recreational soccer players completed a 90-minute over-ground soccer match-simulation. Integrated to the match-simulation were 45° unanticipated side cutting tasks using a 4-5 m·s-1 approach speed. Performance outcomes, peak knee abduction moments (peak KAM), and whole-body dynamic stability variables were calculated for the side cutting tasks. A reduction in the capacity to generate medio-lateral forces from sagittal methods may explain the drop in average medial CoM acceleration and change of direction angle. An ankle movement strategy, represented by a lateral movement of the centre of pressure (CoP) position, appears to have been deployed to mitigate any additional drop in side-cutting performance. A single match-simulation may be insufficient to increase injury risk markers unless the individuals are already showing signs of a reduced ability to mitigate unnecessary movement deviations
EFFECTS OF TAI CHI PRACTICE ON POSTURAL SWAY DURING STANDING BALANCE
Get PDFThe purpose of this study was to investigate the effects of Tai Chi practice on postural sway during standing. Thirty-eight older people participated during COVID-19 extended restrictions, a Tai Chi group (n=18, more than five years’ experience) and a Control group (n=20, no Tai Chi experience). Postural sway was quantified under four different conditions:1) eyes open (EO); 2) eyes closed (EC); 3) eyes open and cross step with right leg forward (ER) and 4) cross step with left leg forward (EL). Significantly less postural sway was observed in Tai Chi group, particularly during EO and EL conditions. The findings of this study support the positive effects of Tai Chi practice on balance control. During the COVID-19, although older people in the nursing home limited their outdoor mobility, Tai Chi practice maintained their physical function during standing balance