The purpose of this study was to explore the utility of an 8-week rope skipping intervention in enhancing standing long jump performance was assessed by means of specific kinematic parameters acquired by 3-D space photography. The fifteen male college students from the physical education institute were randomly recruited as the research subjects. Participants first completed a standing long jump test without rope skipping intervention. Participants subsequently took part in a second standing long jump test after rope skipping training. Two high-speed digital cameras with 100 Hz sampling rate were synchronized to capture the movement. The captured images were processed using motion analysis suite, and the markers attached to joints on images were optical auto capture. Based on the results, the velocity of the center of gravity at take-off and landing were significantly improved. In addition, the study confirmed the requirement for forward tilt of the hip joint at landing to increase the velocity of the center of gravity and hence long jump distance. The detailed kinematic analysis described here provided further evidence of the benefits of integrating non-specialized and specialized training activities to enhance athletic performance and offers a contribution to movement theory and practice.

The purpose of this study was to explore the kinematical characteristics of jumping discus throwing. Eight male right-handed discus throwers who used to practice the jumping throwing technique were recruited as participants. Two high-speed digital cameras with 120 Hz sampling rate were synchronized to capture the movement. The captured images were processed using a motion analysis suite, and the markers attached to joints on images were digitized manually. Based on the results, throwers should keep smaller the shoulder–hip twisting and the right anterior superior iliac spine (abbreviated: ASIS) in front of the right acromion (for right-handed throwers) from the instant the right foot lands to the instant the left foot lands, before the instant of the right foot lands; keep the discus at a depressed position; and reduce the time before discus release, particularly the time of the non-support phase and the second single-support phase. Additionally, release velocity must be improved because throwing distance is directly proportional to squared release velocity. In conclusion, the current study demonstrated comprehensive kinematical analyses, which can be used to instruct the jumping discus throwing technique with duration and angle characteristics of throwing movement for athletes by coaches with videos.

This study aimed to explore the kinematic characteristics of males using various foot landing strategies. The participants were fifteen male students from Physical Education College, Huaibei (non-professional runners, who did not have a fixed running landing strategy mode) (mean height = 178.20 cm; mean weight = 67.60 kg; mean age = 19.40 years). In this experiment, the running model of different foot landing strategies (forefoot strike, FFS and rearfoot strike, RFS) were analyzed using two high-speed cameras captured simultaneously at a sampling rate of 100 Hz. According to the results, the runners with better sports performance have shorter contact time, longer flight time, lower duty factor, larger stride angle, faster V COG, greater A COG, and knee and ankle angles which were crucial kinematics factors to enhance the running. Therefore, this study recommends that coaches or researchers can use photography to analyze novice runners who do not have a fixed landing pattern when running with RFS, the characteristics of running style was closely related to the flight times, and running with FFS was closely related to the stride angle.

Shot put is a throwing exercise in track and field. Performance has a strong relationship with the thrower’s height, technique, and energy transferred. The purpose of this study was to compare basic kinematics, joint movement, shot mechanical energy, and joint energy of the male glide-style shot put between high-performance (HP) and low-performance (LP) athletes. Data for 12 right-handed male shot putters with glide-style was captured at the National Games held in Taipei city in 2013. The HP ( n = 6) and LP ( n = 6) groups were classified according to their best throwing distance in the competition. Additionally, the 2D kinematics of their joints and shots were obtained by Kwon 3D motion analysis. Finally, the kinematics and energy were calculated in Excel software package. Results showed significant differences in throwing distance, the relationship between throwing distance and body height index (RDH index), release velocity, and the shoulder-shot (BSX) angle at right toe-off ground instant (RTF) and the angle difference between the right toe-off instant and release instant (RI-RTF) between the HP and LP groups. However, the energy of the joints and shots were not significantly different between the two groups. The better throwers exhibited a faster release velocity, accompanied by a smaller change in the SSX angle, and the SSX angle can be used by the coach to assess the body’s forward or backward tilt during training.

Purpose: This study aimed to explore the impact of different landing methods on leg movement ability and the relationship between various parameters of leg movement. Methods: This work parameters including stride, contact time, flight time, duty factor, stride angle, vertical stiffness, leg stiffness and peak vertical ground reaction force. Thirty healthy subjects voluntarily participated in this study. In this experiment, each subject was required to perform two tests on a treadmill (using a speed of 10 km/h and 160 spm) (The interval between two experiments is 7 days). In the first test, subjects used RFS. In the second test, FFS was used. A high-speed video camera was used to collect the images and the Kwon3D motion analysis suite was used to process the images in this experiment. Results: The findings of this study revealed that runners employing the forefoot strike FFS method exhibited several favorable characteristics in contrast to those using the rearfoot strike RFS method. These included shorter contact time, longer flight time, reduced duty cycle, increased stride angle and heightened leg stiffness. Additionally, peak vertical ground reaction forces were significantly elevated in females. Conclusions: While rear foot strike RFS demonstrates a notable enhancement in leg stiffness among female runners with low leg stiffness, it concurrently leads to a significant increase in peak vertical ground reaction force and imposes a greater load on the legs. However, this phenomenon is not observed among male participants.

Objective: To compare lower-extremity neuromuscular and biomechanical characteristics during single-leg drop landing under single-task and cognitive–motor dual-task conditions in individuals with chronic ankle instability (CAI). Methods: Twenty-three male participants with unilateral CAI completed single-leg drop landings from a 30-cm platform under single-task and auditory 2-back dual-task conditions in randomized order using a within-participant repeated-measures design. Whole-body three-dimensional kinematics, ground reaction force (GRF), and surface electromyographic (sEMG) signals from eight muscles of the affected limb were recorded synchronously. Outcomes included GRF and dynamic-stability measures, hip, knee, and ankle joint angles and internal moments, muscle activation, and co-contraction indices (CCIs). Depending on the distribution of paired differences, two-sided paired-samples t -tests or Wilcoxon signed-rank tests were used. Effect sizes were reported as Cohen's dz or rank-biserial correlations (rrb), respectively. Results: Compared with the single-task condition, the dual-task condition produced a higher peak vertical GRF (vGRF; p = 0.004, dz = 0.66) and smaller hip flexion angles at peak vGRF ( p = 0.033, rrb = −0.507) and maximum knee flexion ( p = 0.012, rrb = −0.587). At maximum knee flexion, the internal hip extension moment was lower ( p < 0.001, dz = −0.80), whereas the internal ankle plantarflexion moment was higher ( p = 0.028, dz = 0.49). The dual-task condition was also associated with lower lateral gastrocnemius root-mean-square activation ( p = 0.002, dz = −0.75), higher peak tibialis anterior activation ( p = 0.015, dz = 0.55), higher peak vastus lateralis activation ( p = 0.001, dz = 0.77), and a lower peroneus longus–medial gastrocnemius CCI ( p = 0.030, dz = −0.48). No significant between-condition differences were observed in average vertical loading rate, time to stabilization, time to peak vGRF, hip flexion at initial contact, the measured knee and ankle joint angles, or frontal-plane joint angles. Conclusion: In individuals with CAI, a concurrent working-memory task was associated with higher peak impact, reduced hip flexion at selected post-contact events, and selective changes in net internal joint moments and lower-extremity sEMG measures. These findings indicate that dual-task effects on landing control are outcome- and event-specific rather than uniform across biomechanical and neuromuscular domains.