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AI-BASED MARKERLESS SINGLE-CAMERA MOTION ANALYSIS FOR ESTIMATING KNEE AND HIP JOINT KINEMATICS DURING GAIT
Get PDFThis study aimed to pilot-test a markerless motion analysis approach (i.e., SMARTGAIT) for estimating knee and hip joint kinematics in the sagittal and frontal plane during overground walking. One person (age 24 years) walked four times over an 8-meter distance. Joint kinematics were measured using SMARTGAIT (single RGB smartphone camera) and Vicon (reference system). Angle trajectories of sixteen gait cycles were used for the analysis. Agreement between SMARTGAIT and Vicon angle trajectories was greater in the sagittal plane (hip: Pearson’s r=0.989; knee: r=0.990; root mean square error [RMSE] ≤2.6 deg) compared to the frontal plane (hip: r=0.789; knee: r=0.793; RMSE ≤3.9 deg). These initial results show the potential of SMARTGAIT for measuring lower extremity joint kinematics. The camera perspective may influence the accuracy of SMARTGAIT
“SUPER-SHOES” IN DISTANCE RUNNING: IS THERE A POSSIBLE DOWNSIDE IN TRAINED WOMEN?
Get PDFAlthough “super-shoes” provide a metabolic advantage, anecdotal suggest that consistent wear may contribute to development of knee and hip overuse injuries. The purpose of this study was to compare these injury-related running biomechanics variables between “super-shoes” and traditional training shoes in female distance runners. 18 competitive female runners ran for 5min on a treadmill at 3.6 m/s in “super-shoes” (SUPER) and control shoes (CON) while 3D kinematic and ground reaction force data were collected. Peak knee abduction moment and peak hip internal rotation and abduction moment were larger in SUPER compared to CON but no other biomechanical variables were different between shoes. Findings from this study suggest that “super-shoes” may increase knee loading compared to traditional shoes in female distance runners
INFLUENCE OF LEAN BODY MASS DISTRIBUTION ON GROUND REACTION FORCE AND SNATCH PERFORMANCE IN MALE AND FEMALE WEIGHTLIFTERS
Get PDFThe purpose of this study was to determine the influence of lean mass distribution (LMD) on ground reaction forces (GRF) and snatch performance. Eighteen weightlifters completed dual x-ray absorptiometry scans and performed heavy snatch lifts on force plates. Leg and trunk LMD were correlated with snatch performance, but further analysis revealed that only leg LMD was a significant predictor for male weightlifters. GRF during the first pull were associated with performance for male weightlifters, while GRF during the second pull were more relevant for female weightlifters. Leg LMD was a strong predictor of GRF during both pulls with an emphasis on trunk LMD in females. These results showcase the interrelationships between LMD, GRF production, and snatch performance and provide insight on different determinants of performance in male and female weightlifters
THE EFFECTS OF 8 WEEKS CORE COMBINED LOWER LIMB STRENGTH TRAINING ON ADOLESCENT SWIMMERS\u27 MEDLEY TURNING TECHNIQUE
Get PDFThis study aimed to explore the effects of core combined lower limb strength training on medley turning technique of adolescent swimmers. Ten adolescent swimmers completed the trunk extensor and flexor endurance tests, squat jump test and 200m individual medley race before and after the 8 weeks training. The time of extensor and flexor endurance, jump height, and the maximal acceleration in swimming turns had significantly increased after training. The -5 m to 5 m times, the tuck times, and the hip and knee joint angles had significantly decreased after training. Eight weeks core combined lower limb strength training can improve the core strength and lower limb power, optimize the tuck technique, reduce the -5 m to 5 m time and increase the maximum acceleration during the swimming turns in 200m individual medley
TWO-DIMENSIONAL KINEMATICS DIFFERENCES BETWEEN SEXES IN RUNNERS WITH AND WITHOUT PATELLOFEMORAL PAIN
Get PDFPatellofemoral pain (PFP) is a common injury in runners, especially females, but it is unclear if the kinematic risk factors between the sexes are the same. This study aimed to identify the kinematics of healthy and injured recreational runners with PFP in both sexes. High-speed videos of treadmill running gait in 56 subjects (14 in each injured and non-injured male and female group) were analysed using the Kinovea software. Three kinematic variables associated with PFP were extracted at midstance: knee midstance position, knee flexion angle, and hip adduction angle. Compared with healthy controls, injured females ran with knees more medially positioned (Left p = 0.008, Right p \u3c 0.001), while injured males ran with less knee flexion (Left p = 0.006, Right p = 0.007). These findings suggest that kinematic risk factors associated with PFP are sex-specific
ACUTE EFFECTS OF FOOT STRIKE PATTERN TRANSITION ON TRICEPS SURAE AND TIBIALIS ANTERIOR MUSCLE ACTIVITIES DURING RUNNING
Get PDFThis study aimed to investigate the acute effects of transitioning foot strike patterns on muscle activity in the lateral gastrocnemius (LG), medial gastrocnemius (MG), soleus (SOL), and tibialis anterior (TA) muscles during running. Fifteen healthy male runners with habitual rearfoot strike pattern (RFS) were recruited to complete running with RFS and the forefoot strike pattern (FFS) tests at 9 km/h. The electromyography (EMG) and ground reaction force were collected synchronously. The paired t-tests were used to examine the differences in the root mean square (RMS) between FFS and RFS. The results revealed that the mean RMS for the triceps surae was higher in FFS than in RFS and the muscle co-activation ratio was higher in RFS than in FFS during the pre-activation phase. In conclusion, the acute transitioning to FFS could change muscle activation mode during running
BODY INCLINATION AND MOTION VARIATION OF BODY SEGMENTS IN THE TRIPLE PIROUETTE FOR SKILLED FEMALE DANCERS
Get PDFThe study investigated body inclination angle and motion variation for skilled dancers in the triple pirouette. Eleven skilled female ballet dancers were asked to perform the triple pirouette. A three-dimensional motion capture system was used to calculate the body inclination angle and direction angles of the body segment vectors for evaluating the motion variation of the body segments. Maintaining a small body inclination angle during the triple pirouette, they showed a high commonality of the segment motions in the left shank and left thigh of the support leg as well as the upper and lower torso, while a high individuality was observed in the upper limbs, which would relate to artistic expression and attribute to the skilfulness of dances
RELATIONSHIP BETWEEN PRE-DELIVERY STRIDE AND FAST BOWLING PERFORMANCE IN CRICKET
Get PDFThis study aimed to investigate fast bowler biomechanics during the pre-delivery stride and how they associate with variables previously linked with faster ball release speeds. Kinematic bowling data was collected from 29 elite fast bowlers using 3D motion capture. Pre-delivery stride technique showed multiple significant associations with performance-related variables: more vertical take-off angles correlated with slower run-up velocity; and a larger downward landing velocity associated with less thoracolumbar flexion during the bowling action. Shallower pre-delivery stride take-off angles might therefore be recommended but physical capacity of the bowler should be considered due to the undesirable association between faster run-up velocity and greater front knee flexion at front foot contact
TESTING INJURY RISK IN ACL-RECONSTRUCTED FOOTBALL PLAYERS ON THE FIELD: A PRACTICAL TOOL TO ASSESS CUTTING BIOMECHANICS THROUGH WEARABLE SENSORS
Get PDFThe aim of the present study was to inspect differences between healthy and ACLR football players through a kinematic on-field assessment of cut manoeuvres. 62 (47 healthy, 15 ACLR) were enrolled. The players performed planned 90° changes of direction and unplanned football-specific changes of direction. Kinematics was collected through 8 wearable inertial sensors (MTw Awinda, Xsens). Healthy and ACLR players differed in hip and knee rotation during the entire cut phase (
KINEMATICS OF THE SCISSORS KICK IN THE BREASTSTROKE
Get PDFThis study aimed to clarify the kinematic characteristics of the scissors kick in novice breaststroke swimmers. Six participants exhibited the breaststroke kick and three exhibited the scissors kick. All participants performed two 10-m breaststroke kicks with a board while maintaining a face-down underwater position. The breaststroke kicks were recorded using two synchronized underwater cameras, and three-dimensional analysis was performed on the right-sided kicking movements. The results showed that, with knee flexion, participants who performed scissors kicks showed a significantly greater inversion angle, whereas those who performed normal breaststroke kicks exhibited a change from inversion to eversion before the kick phase. Therefore, it is suggested that the ankle joint may need to be everted while the knee joint flexes to improve the breaststroke kick