Inertial measurement units (IMUs) are possible alternatives to motion-capture systems (Mocap) for gait analysis. However, IMU-based system performance must be validated before widespread clinical use. Therefore, this study evaluated the validity of IMUs using statistical parametric mapping (SPM) for gait analysis. Ten healthy males (age, 30.10 ± 3.28 years; height, 175.90 ± 5.17 cm; weight: 82.80 ± 17.15 kg) participated in this study; they were asked to walk normally on a treadmill. Data were collected during walking at the self-selected speeds (preferred speed, 1.34 ± 0.10 m/s) using both Mocap and an IMU. Calibration was performed directly before each gait measurement to minimize the IMU drift error over time. The lower-extremity joint angles of the hip, knee, and ankle were calculated and compared with IMUs and Mocap; the hip-joint angle did not differ significantly between IMUs and Mocap. There were significant differences in the discrete (max, min, and range of motion) and continuous variables (waveform: 0–100%) of the knee and ankle joints between IMUs and Mocap, particularly on the swing phase (p < 0.05). Our results suggest that IMU-based data can be used confidently during the stance phase but needs evaluation regarding the swing phase in gait analysis.

This study investigated whether an increase in the forefoot bending stiffness of a badminton shoe would positively affect agility, comfort and biomechanical variables during badminton-specific movements. Three shoe conditions with identical shoe upper and sole designs with different bending stiffness (Flexible, Regular and Stiff) were used. Elite male badminton players completed an agility test on a standard badminton court involving consecutive lunges in six directions, a comfort test performed by a pair of participants conducting a game-like practice trial and a biomechanics test involving a random assignment of consecutive right forward lunges. No significant differences were found in agility time and biomechanical variables among the three shoes. The players wearing the shoe with a flexible forefoot outsole demonstrated a decreased perception of comfort in the forefoot cushion compared to regular and stiffer conditions during the comfort test (p < 0.05). The results suggested that the modification of forefoot bending stiffness would influence individual perception of comfort but would not influence performance and lower extremity kinematics during the tested badminton-specific tasks. It was concluded that an optimisation of forefoot structure and materials in badminton shoes should consider the individual's perception to maximise footwear comfort in performance.

The rapid and repetitive badminton lunges would produce strenuous impact loading on the lower extremities of players and these loading are thought to be the contributing factors of chronic knee injuries. This study examined the impact loading characteristics in various groups of badminton athletes performing extreme lunges. Fifty-two participants classified into male skilled, female skilled, male unskilled, and female unskilled groups performed badminton lunge with their maximum-effort. Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronised force platform and motion analysis system. A 2 (gender) x 2 (skill-level) factorial ANOVA was performed to determine the effects of different gender and different playing levels, as well as the interaction of two factors on all variables. Male athletes had faster approaching speed (male 3.87 and female 1.08 m/s), longer maximum lunge distance (male 1.47 and female 1.16 m), larger maximum (male 215.7 and female 121.65 BW/s) and mean loading rate (male 178.43 and female 81.77 BW/s) and larger peak knee flexion moment (male 0.75 and female 0.69) compared with female athletes (P < 0.001). Unskilled athletes exhibited smaller footstrike angle (skilled 45.78 and unskilled 32.35°), longer contact time (skilled 0.69 and unskilled 0.75 s), larger peak horizontal GRF (skilled 1.61 and unskilled 2.40 BW), smaller mean loading rate (skilled 150.15 and unskilled 110.05 BW/s) and larger peak knee flexion moment (P < .05; skilled 0.69 and unskilled 0.75 Nm/BW) than the skilled athletes. In addition, the interaction indicated greater peak GRF impact in female unskilled athletes compared with female skilled athletes (P < 0.001; female skilled 2.01 and female unskilled 2.95 BW), while there was no difference between male participants (P > 0.05; male skilled 2.19 and male unskilled 2.49 BW). These data suggested that male athletes and/or unskilled athletes experience greater impact loading rates and peak knee flexion moment during lunge compared with female and skilled athletes, respectively. This may expose them to higher risk of overuse injuries. Furthermore, female unskilled athletes seemed to be more vulnerable to lower extremity injuries.

[Purpose] The purpose of this study was to examine the effect of modified Pilates exercise on cardiopulmonary function in chronic stroke patients. [Subjects and Methods] Twenty participants (age, 62.7 ± 7.3 years; height, 163.3 ± 8.5 cm; weight, 68.8 ± 10.3 kg) were recruited for this study, and randomly allocated to the modified Pilates exercise group (n=10) or the control group (n=10). Graded submaximal treadmill exercise test was used to examine the status of patients' cardiopulmonary function, based on maximal oxygen intake, at the end of a patient's exercise tolerance limit. [Results] The resting heart rates, maximal oxygen intake, and maximal oxygen intake per kilogram were significantly different after 8 weeks of modified Pilates exercise. In addition, these variables were also significantly different between the Pilates and control groups after 8 weeks. [Conclusion] This study has demonstrated that 8 weeks of modified Pilates exercise program can have a positive influence on patients with chronic stroke, potentially by enhancing the cardiopulmonary function, which may have positive implications for increasing their functional ability.

[Purpose] The purpose of this study was to investigate the effects of an 8-week program of Pilates exercise on gait in chronic hemiplegia patients and to determine whether or not it can be used for rehabilitation in postsrtoke patients. [Subjects and Methods] Twenty individuals with unilateral chronic hemiparetic stroke (age, 66.1 ± 4.4 yrs; height, 162.3 ± 8.3 cm; weight, 67.4 ± 12.3 kg) participated in this study and were randomly allocated equally to either a Pilates exercise group or a control group. To identify the effects of Pilates exercise, a 3-D motion analysis with 8 infrared cameras was performed. [Results] For the gait parameters, improvements were found in the Pilates exercise group for all variables, and statistical significance was observed for stride length, gait velocity, knee range of motion and hip range of motion. For the asymmetry indexes, insignificant improvements were found for all variables in the Pilates exercise group. [Conclusion] In conclusion, an 8-week program of Pilates exercise had a positive influence on improving the gait ability of poststroke patients, and the intervention could be applied to poststroke patients with various levels of physical disability by adjusting the intensity of training.