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THE EFFECTS OF SHOE TYPE ON BIOMECHANICAL AND PHYSIOLOGICAL RESPONSES TO STEPPING AND INCLINED WALKING
Get PDFThe purpose of this study was to examine the effect of hiking shoes and hiking boots on the biomechanical responses to a stepping task and physiological responses to an inclined walking task. Participants (n = 16) performed six two minute stepping trials at a stepping rate of 72 bpm; three trials in hiking boots and three trials in hiking shoes. Following the stepping task, participants (n = 19) walked at 3.0 mph and 10% grade for five minutes in hiking shoes and hiking boots. Lower limb joint angles and moments were calculated using Visual 3D. Physiological data was averaged over the last three minutes of the stepping task to determine mean variables during steady state exercise. Results showed that during the lowering phase of the stepping cycle, ankle ROM and ankle and knee moments were significantly greater in hiking shoes than hiking boots, indicating that no compensatory mechanisms of the knee and hip were implemented due to restricted ankle ROM. Additionally, VO2 and VE were significantly greater in the hiking shoe condition during the inclined walking task. While these variables are statistically significant, they may not be practically significant in an actual hiking scenario, as the magnitudes of differences observed in variables were minimal. Use of either shoe or boot may not result in an increased risk of injury, therefore leaving the choice of footwear up to the hiker’s personal preference
SOURCES OF ERROR WHEN MEASURING ACHILLES TENDON MECHANICS DURING RUNNING ACTIVITIES
Get PDFAccurate measurements of tendon mechanics are necessary for biomechanists when trying to identify injury risk factors, optimise athletic performance and develop musculoskeletal models. Measuring Achilles tendon (AT) mechanics dynamically is now possible by combining motion capture and ultrasound (US). The aim of this study was to quantify sources of error when measuring AT length using motion capture and US, and establish their effect on calculated strain values. Errors in AT insertion tracking and data synchronisation caused differences in AT length and moment arm of 5.3 ± 1.1 mm and 11.2 ± 0.9 mm, respectively; this decreased calculated AT peak strain from 11.6 ± 3.5% to 5.4 ± 2.5%. These differences could significantly impact a researcher‘s interpretation of the effects of footwear, technique, and specific kinematics on AT loading
THE EFFECTS OF COMPRESSION GARMENTS ON RECOVERY PROCESS AFTER A MODERATE-INTENSITY RESISTANCE EXERCISE
Get PDFThe purpose of this study was to determine whether compression garments (CG) are effective in facilitating recovery after moderate-intensity resistance exercise. Fifteen male subjects performed experimental trials in CG and control conditions during recovery after a deep squat exercise. Jump height, muscle soreness, and creatine kinase (CK) were measured before, immediately after, 24, 48 and 72 h after exercise. The CK was higher at 24h after exercise than before exercise in both conditions (p = .009, ES = 1.58). The jump height decreased immediately (p = .003, ES = -1.22) and 24H (p = .012, ES = -.98) after exercise in both conditions. However, there were no significant differences in CK, jump height and muscle soreness between the two conditions at any time. The application of CG cannot aid in the recovery after a moderate-intensity resistance training
THE INCIDENCE AND NATURE OF NON-CONTACT INJURIES IN U.S. WOMEN’S RUGBY-7S
Get PDFThe aim of this study was to prospectively determine non-contact injury incidence and mechanisms among U.S. amateur women’s Rugby-7s. Non-contact injuries occurred frequently among the U.S. women population (26.5/1000ph; 29% of all injuries; n=167). The incidence of non-contact injuries occurred at similar rates among backs (58%, 23.9/1000ph, CI:19.1-29.6) and forwards (42%, 19.3/1000ph, CI:14.4-25.3; RR:1.04, p=0.816). Non-contact injuries resulted in 58.4 mean days absence from play. This study demonstrates a greater proportion of match injuries among U.S. amateur women Rugby-7 participants were related to non-contact mechanism when compared to International women participants. Therefore, U.S. women Rugby-7 players would benefit from prevention programs to minimize non-contact injury risks
EFFECTS OF BATON EXCHANGE PAIR STRATEGIES ON THE RELAY PERFORMANCE OF COLLEGE STUDENTS IN PHYSICAL EDUCATION CLASS
Get PDFWe examined the effects of baton exchange pair strategies on the college students‘ relay performance in physical education (PE) class. The subject included 72 students in relay PE class. A multiple regression analysis was conducted by setting 2 x 50 m relay time as an dependent variable and the sum of each personal 50-m run time (50RT) for a baton exchange pair (Σ50RT), delta of each 50RT (Δ50RT), and distance between from the start line of baton exchange zone and the receiver’s position to start running (dSL) as independent variables. All independent variables were significant; the coefficient of determination of the multiple regression model was 0.601 (P \u3c 0.05). The Σ50RT as physical resource accounted for 31.6%, Δ50RT for 16.9%, and dSL for 11.6% of the variance of 2 x 50 m run time. Thus, Δ50RT and dSL were considered important in strategy
EFFECT OF THE RECTUS FEMORIS KINESIO-TAPING ON MALE ATHLETES DURING THE STOP-JUMP TASK POST-FATIGUE
Get PDFThis study aimed to investigate the biomechanics of the stop-jump task under the effect of Kinesio-taping (KT) applied on rectus femoris before and after fast-induced fatigue on male athletes. Nine male college athletes served as the subject. Two force plates and ten high-speed cameras were synchronized to capture the stop-jump tasks. The results showed that the jumping height decreased, the vertical ground reaction force (GRF) and the peak proximal tibia anterior shear force increased, and the time to peak vertical GRF was earlier after intervened fatigue in the non-taping group. We also found that the peak proximal tibia anterior shear force did not increase after fatigue when following the application of KT. We recommend that KT is used to intense exercises or competition with repeated jumping
USE OF SELF-ORGANIZING MAPS TO STUDY SEX- AND SPEED-DEPENDENT CHANGES IN RUNNING BIOMECHANICS
Get PDFSelf-organizing maps (SOM) are a type of artificial neural network for 1) clustering variables and visualizing large datasets and 2) quantifying coordination patterns. The purpose of this study was to use a SOM to investigate the effect of sex and speed on coordination patterns during running. Seventeen females and 15 males ran at their long-slow distance (LSD) training speed and at a speed 30% faster than LSD. Thirty-seven biomechanical variables (gait parameters, joint kinematics, coupling angle variability, EMG, and impact kinetics) were recorded and/or calculated, and analyzed with a SOM. The SOM analysis showed a significant shift in coordination pattern for males and females as running speed increased. This shift was characterized primarily by increases in the rate of ground reaction force loading, tibial impact shock, step lengths, and medial gastrocnemius muscle activation
Weight-bearing Versus Active Prone Hip Rotation Range of Motion
Get PDFHip rotation range of motion (ROM) is usually measured in a non-weight bearing (NWB) status, however, people participate in sporting activities when in a weight-bearing (WB) condition. Since measuring in a WB status may be more relevant, the purpose of the study was to compare WB hip rotation ROM measures with a NWB active, prone (AP) measure. The investigators measured 112 participant’s (19.3±1.4 yrs., 174.0±11.9 cm, 73.0±12.6 kg) bilateral hip internal rotation (IR) and external rotation (ER) in both WB and NWB conditions. Paired t-tests were used to test for significant differences with an alpha of (p\u3c .05). AP IR measures (37.0 ± 9.8 and 36.7 ± 8.4) were significantly greater than WB IR measures ( 20.9 ± 9.4 and 23.2 ± 8.7) and WB ER measures (42.1 ± 11.8 and 38.3 ± 11.4) were significantly greater than AP ER measures (31.1 ± 7.0 and 26.2 ± 5.7). Hip rotation ROM peak values differ significantly between the two measurement methods and should be considered when measuring athletes
THE EFFECT OF SHOE TYPE ON VARIOUS KINETIC AND KINEMATIC VARIABLES DURING STEP-UP AND STEP-DOWN MOTIONS
Get PDFThe purpose of this study was to examine the effect of shoe type on the biomechanical responses to a stepping task. Participants (n = 8) performed six two minute stepping trials at a stepping rate of 72 bpm; 3 trials in hiking boots and 3 trials in hiking shoes. Lower limb joint angles and moments were calculated using Visual 3D. No significant differences were found in step down peak ground reaction forces (GRF), ankle, knee, and hip range of motion (ROM), joint moments, joint flexion at step down contact, or toe clearance height between footwear conditions. Due to the lack of differences found between footwear conditions, the use of either a hiking shoe or boot may not result in an increased risk of injury, therefore leaving the choice of footwear to the hiker’s personal preference
THE INFLUENCE OF PROLONGED RUNNING AND FOOTWEAR ON LOWER EXTREMITY JOINT STIFFNESS
Get PDFThe purpose of this study was to compare leg, knee and ankle stiffness over the course of a prolonged treadmill run (PTR) in neutral and stability footwear. Fourteen male habitual, rearfoot runners completed two biomechanical testing sessions where they ran for 21 minutes at their preferred running speed in a neutral shoe, then changed either into the same neutral shoe or a stability shoe and ran a further 21 minutes on a force instrumented treadmill. No differences were observed in leg stiffness (p \u3e 0.05). Knee stiffness increased during the first 21 minutes (p = 0.003), while ankle stiffness reduced at minute 21 (p = 0.004) and minute 44 (p = 0.006). No differences were observed between footwear conditions (p \u3e 0.05). These results suggest that over the course of a PTR, shock attenuation strategies change, and this change may be detrimental to the knee joint