A recreational athlete was defined as a person who played sports or exercise at least three times a week for a total of at least 6 h per week without following a professionally designed training program. The mean age, body mass, and height of the male subjects were 22.34 ± 3.09 years, 78.7 ± 9.4 kg, and 1.78 ± 0.06 m, respectively. The mean age, body mass, and height of the female subjects were 23.20 ± 2.74 years, 60.0 ± 11.1 kg, and 1.63 ± 0.07 m, respectively. Subjects were excluded from the study if they had a history of musculoskeletal injury or any disorder that interfered with motor function. The use of human
subjects in this study was approved by the University Biomedical Institutional Review Board. A written informed consent was obtained Epigenetics Compound Library from each subject before data collection. Each subject was asked to perform five successful trials of a stop-jump task that consisted of an approach run up to five steps followed by a two-footed landing, and two-footed vertical takeoff for maximum height.28 A successful trial was defined as a trial in which the subject performed the stop-jump task as asked and all the data were collected. The subject was asked to perform the stop-jump task naturally as they did for a jump shot or grabbing a rebound in basketball, www.selleckchem.com/products/chir-99021-ct99021-hcl.html and at the maximum approach speed with
which they felt comfortable to perform the task. The specific techniques of the stop-jump task were not demonstrated to subjects to avoid coaching bias. Passive reflective markers were placed on the critical body landmarks as described in a previous study.28 A videographic
and analog acquisition system with eight video cameras (Peak Performance Technology, Inc., Englewood, CO, USA) and two force plates (Bertec Corp., Worthington, OH, USA) was used to collect three-dimensional (3-D) coordinates of reflective markers at a sample rate of 120 frames/s and next ground reaction forces at a sample rate of 2000 samples/channel/s. A telemetry electromyographic (EMG) data acquisition system (Konigsburg Instruments, Pasadena, CA, USA) was used to collect EMG signals for the vastus medialis, rectus femoris, vastus lateralis, semimembranosus, biceps femoris, medial, and lateral head of gastrocnemius muscles at a sample rate of 2000 samples/channel/s. The videographic, force plate, and EMG data collections were temporally synchronized. The raw 3-D coordinates of the reflective markers during each stop-jump trial were filtered through a Butterworth low-pass digital filter at a cutoff frequency of 10 Hz. The 3-D coordinates of lower extremity joint centers were estimated from the 3-D coordinates of the reflective markers. Lower extremity kinematics and kinetics were reduced for each trial as described in the previous study.