Browse

Purpose: To compare the pacing profiles of elite track athletes with intellectual impairments (II) and those with Down syndrome (DS) in 400- and 1,500-m track events. Methods: The pacing data of 67 elite runners participating in the final 400-m (both genders) and 1,500-m (only males) track events of the Global Games (2023) were analyzed. Runners competed in two classes: a class for runners with II (without DS) and a separate class for runners with DS. Results: For the 400-m event, male and female runners in both classes decelerated from the first segment (0–200 m) to the second segment (200–400 m) as the time main effect was significant (p < .001); however, the pacing strategy for both genders differed between the II and DS class as reported by the significant Gender × Class interaction effect (p < .001). The running velocity over the two segments of the race decreased more significantly for the II runners without DS. There was also a significant interaction effect for the 1,500-m race (p < .001). The DS runners show a more significant drop in running velocity over the split times of the race and with more varied fluctuations compared with the II runners without DS. Conclusion: This study highlights the significant differences in pacing between 400- and 1,500-m elite runners with II and with and without DS. Elite runners with DS run at an overall slower velocity and follow a significantly different pacing pattern compared with runners with II without DS. Our findings show that runners with DS are less able to regulate their exercise intensity over the race than runners with II without DS.

Context: Male ice hockey players face a high risk of hip and groin symptoms. It is not known how symptoms change over the course of a single season. The purpose of this study was to determine the change in hip and groin symptoms over the course of a season in male ice hockey players and to identify the relationship between a brief preseason physical screen for future hip and groin symptoms. Design: Prospective cohort study. Methods: Members of 2 collegiate male ice hockey clubs (n = 51, 19.47 [1.30] y) underwent preseason physical screens of hip strength and range of motion. They also completed the Quality of Life (QoL) and Sport subscales of the Hip and Groin Outcome Score (HAGOS) preseason and postseason. Paired samples t tests were conducted to determine the change in subscale scores from preseason to postseason. Linear regression models were conducted to identify the relationship between symptoms and the results of the preseason screens. Results: There was a decline in the HAGOS QoL (−3.6; 95% CI, 0.8–6.3; P = .01) and the HAGOS Sport (−4.1; 95% CI, 0.1–8.3; P = .05) over the course of the competitive season. Lower preseason scores were associated with having lower postseason QoL (β = 0.74; 95% CI, 0.43–1.04; P < .01) and Sport (β = 0.58; 95% CI, 0.26–0.89; P < .01) subscale scores. Preseason screens were not significantly associated with end-of-season HAGOS Sport (R ² = .05, P = .25) or QoL (R ² = .09, P = .09) scores. Conclusions: Hip and groin symptoms worsened over the course of a competitive season in male ice hockey players without preventative measures in place. Preseason physical screens of hip strength and range of motion were not associated with future disability. Hip and groin symptoms are not self-limiting and are likely to worsen over the course of a single season in male ice hockey players.

Context: It is recommended that arterial occlusion pressure (AOP) should be measured prior to the use of blood flow restriction training. Previous studies have not compared measures of AOP when using 2 methods of cuff inflation commonly reported in the literature. Design: A cross-sectional observational study was used to compare the measurement of brachial artery AOP as measured using pulse wave Doppler ultrasound (PWDOP) and continuous wave Doppler ultrasound (CWDOP) devices when inflating the cuff with a research/clinical-grade Hokanson (HOK) rapid cuff inflation system and manually (MAN) with a hand pump and gauge. Methods: We made simultaneous measures of brachial artery AOP in 20 males and 21 females using PWDOP and CWDOP devices when using HOK and MAN cuff inflation methods. Data were analyzed with a linear mixed model analysis of variance and Bland–Altman plots. Results: There was not a significant main effect for the overall differences in AOP as measured using PWDOP (121.7 ± 14.7 mmHg) and CWDOP (121.3 ± 14.5 mmHg; P = .3641). There was a significant overall main effect for AOP measured using the HOK (122.7 ± 14.6 mmHg) and MAN (120.3 ± 14.6 mmHg) cuff inflation methods (P < .0001) and between males (128.2 ± 13.7 mmHg) and females (115.2 ± 12.5 mmHg; P = .0034). Bland–Altman plots revealed minimal bias and reasonable limits of agreement between PWDOP and CWDOP measures of AOP when using HOK (0.8 mmHg; 95% CI, −4.7 to 3.0 mmHg) and MAN (0.4 mmHg; 95% CI, −5.3 to 4.5 mmHg) cuff inflation methods. Conclusions: The cessation of an audible pulse using CWDOP is in agreement with the complete obstruction of the arterial blood flow observed using PWDOP. Although statistically significant, small differences in PWDOP and CWDOP measures of AOP when using HOK and MAN cuff inflation methods are of little practical significance. A hand-held CWDOP device and a handpump/gauge can be used to measure AOP.

The purpose of the present study was to clarify the dynamic factors that induce pelvic rotation when soccer players kick a ball toward angled directions using an instep kick. Nine experienced, right-footed, male soccer players instep kicked a stationary ball in 3 different angled directions, 15°, 45°, and 75° relative to the run-up direction, and a motion capture system with a force plate recorded the kicking data. Kinematic and kinetic variables of the support leg, associated with pelvic rotation about the vertical axis, were compared among the kicking conditions. The pelvic rotation significantly increased in response to larger kicking angles, and it coincided with increase of the support leg hip joint and foot segment rotation about the vertical axis. The joint torque at the support leg hip joint significantly increased with the kicking angles. Additionally, the interaction torque due to the ground reaction force was the primary factor driving foot segment rotation relative to the force plate in angled kicking conditions, whereas no remarkable action of the free moment existed. Instep kicks toward angled directions involve a mechanism that increases the pelvic rotation about the support leg’s hip joint and foot segment, which differs from the mechanism involved in straight kicks.

Context: Anterior cruciate ligament reconstruction (ACLR) is a common surgical procedure after injury. However, ACLR contributes to aberrant biomechanical movement patterns that influence secondary injury or joint degeneration. Higher body size may influence gait and landing biomechanics differently between males and females. The purpose of this study was to investigate the influence of sex on the association between body mass index (BMI) and knee biomechanics long-term after ACLR recovery. Design: Sixteen female (BMI: 27.7 [5.4]) and 14 male (BMI: 24.2 [5.5]) participants who had a history of ACLR performed walking and drop vertical jump tasks. Methods: The knee-flexion angle (KFA), external knee flexion moment, knee abduction moment (landing), and knee adduction moment (gait) were measured using 3D motion capture. Body fat percentage was assessed using a BOD POD. Moderated regression evaluated the influence of sex on the association between BMI and biomechanical outcomes after adjusting for body fat percentage. Results: There was a significant interaction between sex and BMI on the KFA at heel contact (P = .01), peak KFA (P = .04), and peak external knee flexion moment (P = .05) during gait and on the KFA at ground contact during landing (P = .04). Higher BMI was associated with smaller KFAs at heel contact (P = .03), smaller peak KFAs during gait (P = .02), and smaller external knee flexion moments (P = .01) but only in females. Similarly, a higher BMI was associated with a smaller KFA at ground contact during landing (P = .03) but only in females. There was no sex by BMI interaction on the knee adduction moment during gait (P = .657) or on the knee abduction moment during landing (P = .643). Moreover, sex and BMI were not independent predictors of the knee adduction moment during gait or the knee abduction moment during landing (all P > .05). Conclusions: The association between sex and BMI may have implications for posttraumatic knee osteoarthritis and ACL reinjury, and female sex and high BMI should be considered when designing individualized rehabilitation programs. These findings suggest that females with high BMI may benefit from interventions to improve knee flexion during landing and gait.