Low back pain is a commonly reported problem among recreational surfers. Some individuals report that wearing a vest with an inflatable bladder that alters trunk angle may help to alleviate pain. The purpose of this study was to determine whether such a vest has an effect on muscle activation and extension of the lower back. Twelve recreational surfers completed 12 paddling trials at 1.1 m/s in a swim flume on both a shortboard and a longboard on 2 separate days. Three conditions of no vest, vest uninflated, and vest inflated were presented to participants in random order. Surface EMG and trunk angle were acquired via wireless sensors placed over the right erector spinae, mid-trapezius, upper trapezius, and latissimus dorsi. Wearing the inflated vest affected muscle activation: erector spinae and mid-trapezius demonstrated a significant decrease in activation relative to wearing no vest (12% and 18% respectively, p < .05). Trunk extension was also significantly reduced when the vest was inflated (18% reduction, p < .05). Results were similar for both the short and longboard, though this effect was greater while paddling the larger board. These results suggest that a properly inflated vest can alter trunk extension and muscle activity while paddling a surfboard in water.
Jeff A. Nessler, Thomas Hastings, Kevin Greer, and Sean C. Newcomer
Kevin M. Guskiewicz, Gregory G. Degnan, and Thomas L. Schildwachter
Ligamentous injuries of the wrist and hand are the most common upper extremity injuries seen in young athletes. Unfortunately, these injuries are also the most frequently misdiagnosed. The “sprained wrist” often becomes the diagnosis of convenience, especially once a fracture has been ruled out. In many cases the athlete is treated symptomatically with cryotherapy, immobilization, and rest, and returns to activity as pain allows. Concern, however, has increased recently over potential complications related to associated ligamentous injuries in young athletes. The most common recognized, carpal instability is between the scaphoid and the lunate, the so-called scapholunate dissociation (3).
Thomas Sawczuk, Ben Jones, Sean Scantlebury, and Kevin Till
Purpose: To assess the relationships between training load, sleep duration, and 3 daily well-being, recovery, and fatigue measures in youth athletes. Methods: Fifty-two youth athletes completed 3 maximal countermovement jumps (CMJs), a daily well-being questionnaire (DWB), the perceived recovery status scale (PRS), and provided details on their previous day’s training loads (training) and self-reported sleep duration (sleep) on 4 weekdays over a 7-week period. Partial correlations, linear mixed models, and magnitude-based inferences were used to assess the relationships between the predictor variables (training and sleep) and the dependent variables (CMJ, DWB, and PRS). Results: There was no relationship between CMJ and training (r = −.09; ±.06) or sleep (r = .01; ±.06). The DWB was correlated with sleep (r = .28; ±.05, small), but not training (r = −.05; ±.06). The PRS was correlated with training (r = −.23; ±.05, small), but not sleep (r = .12; ±.06). The DWB was sensitive to low sleep (d = −0.33; ±0.11) relative to moderate; PRS was sensitive to high (d = −0.36; ±0.11) and low (d = 0.29; ±0.17) training relative to moderate. Conclusions: The PRS is a simple tool to monitor the training response, but DWB may provide a greater understanding of the athlete’s overall well-being. The CMJ was not associated with the training or sleep response in this population.
Thomas A. Stoffregen, M. Russell Giveans, Sebastien Villard, Jane Redfield Yank, and Kevin Shockley
When two standing people converse with each other there is an increase in their shared postural activity, relative to conversation with different partners. We asked pairs of participants to converse with each other or with experimental confederates while standing on rigid and nonrigid surfaces. On the rigid surface, shared postural activity was greater when participants conversed with each other than when they conversed with confederates. In addition, the strength of interpersonal coupling increased across trials, but only when members of a dyad conversed with each other. On the nonrigid surface, postural sway variability increased, but we found no evidence that shared postural activity was different when participants conversed with each other, as opposed to conversing with confederates. We consider several possible interpretations of these results.
Stef Feijen, Angela Tate, Kevin Kuppens, Thomas Struyf, Anke Claes, and Filip Struyf
Context: The latissimus dorsi plays a major role in generating the propulsive force during swimming. In addition, stiffness of this muscle may result in altered stroke biomechanics and predispose swimmers to shoulder pain. Measuring the flexibility of the latissimus dorsi can be of interest to reduce injury. However, the reliability of such measurement has not yet been investigated in competitive swimmers. Objective: To assess the within-session intrarater and interrater reliability of a passive shoulder flexion range of motion measurement for latissimus dorsi flexibility in competitive swimmers. Design: Within-session intrarater and interrater reliability. Setting: Competitive swimming clubs in Flanders, Belgium. Participants: Twenty-six competitive swimmers (15.46 [2.98] y; 16 men and 10 women). Intervention: Each rater performed 2 alternating (eg, left-right-left-right) measurements of passive shoulder flexion range of motion twice, with a 30-second rest period in between. Main Outcome Measures: The intraclass correlation coefficients were calculated to assess intrarater and interrater reliability. Results: Interrater intraclass correlation coefficient ranged from .54 (95% confidence interval [CI], −.16 to .81) to .57 (95% CI, −.24 to .85). Results for the intrarater reliability ranged from .91 (95% CI, .81 to .96) to .94 (95% CI, .87 to .97). Conclusion: Results of this study suggest that shoulder flexion range of motion in young competitive swimmers can be measured reliably by a single rater within the same session.
Javier T. Gonzalez, Martin J. Barwood, Stuart Goodall, Kevin Thomas, and Glyn Howatson
Unaccustomed eccentric exercise using large muscle groups elicits soreness, decrements in physical function and impairs markers of whole-body insulin sensitivity; although these effects are attenuated with a repeated exposure. Eccentric exercise of a small muscle group (elbow flexors) displays similar soreness and damage profiles in response to repeated exposure. However, it is unknown whether damage to small muscle groups impacts upon whole-body insulin sensitivity. This pilot investigation aimed to characterize whole-body insulin sensitivity in response to repeated bouts of eccentric exercise of the elbow flexors. Nine healthy males completed two bouts of eccentric exercise separated by 2 weeks. Insulin resistance (updated homeostasis model of insulin resistance, HOMA2-IR) and muscle damage profiles (soreness and physical function) were assessed before, and 48 h after exercise. Matsuda insulin sensitivity indices (ISIMatsuda) were also determined in 6 participants at the same time points as HOMA2-IR. Soreness was elevated, and physical function impaired, by both bouts of exercise (both p < .05) but to a lesser extent following bout 2 (time x bout interaction, p < .05). Eccentric exercise decreased ISIMatsuda after the first but not the second bout of eccentric exercise (time x bout interaction p < .05). Eccentric exercise performed with an isolated upper limb impairs whole-body insulin sensitivity after the first, but not the second, bout.
Jerred Junqi Wang, James J. Zhang, Kevin K. Byon, Thomas A. Baker, and Zhenqiu Laura Lu
Building on schema theory, the current study highlighted the role of brand-event personality fit (BEPF) in sport-event sponsorship communications and empirically examined its impact on sponsors’ consumer-based brand equity (CBBE) in the setting of American college football. Three studies were conducted to refine a sound measurement scale of BEPF and examine the structural relationships between BEPF and CBBE. Research findings confirmed the validity and reliability of the proposed BEPF measurement scale and revealed a series of positive relationships between crucial subdimensions of BEPF (i.e., responsibility fit, emotionality fit, and aggressiveness fit) and CBBE (i.e., brand awareness/association, perceived value, and brand loyalty). The findings offer brand managers specific references as to which aspects of BEPF should be prioritized in their promotional communications to build CBBE. Event marketers could also use the findings to communicate with corporations regarding potential or continued sponsorship agreements.
Thomas I. Gee, Duncan N. French, Karl C. Gibbon, and Kevin G. Thompson
This study investigated the pacing strategy adopted and the consistency of performance and related physiological parameters across three 2000-m rowing-ergometer tests.
Fourteen male well-trained rowers took part in the study. Each participant performed three 2000-m rowing-ergometer tests interspersed by 3–7 d. Throughout the trials, respiratory exchange and heart rate were recorded and power output and stroke rate were analyzed over each 500 m of the test. At the completion of the trial, assessments of blood lactate and rating of perceived exertion were measured.
Ergometer performance was unchanged across the 3 trials; however, pacing strategy changed from trial 1, which featured a higher starting power output and more progressive decrease in power, to trials 2 and 3, which were characterized by a more conservative start and an end spurt with increased power output during the final 500 m. Mean typical error (TE; %) across the three 2000-m trials was 2.4%, and variability was low to moderate for all assessed physiological variables (TE range = 1.4−5.1%) with the exception of peak lactate (TE = 11.5%).
Performance and physiological responses during 2000-m rowing ergometry were found to be consistent over 3 trials. The variations observed in pacing strategy between trial 1 and trials 2 and 3 suggest that a habituation trial is required before an intervention study and that participants move from a positive to a reverse-J-shaped strategy, which may partly explain conflicting reports in the pacing strategy exhibited during 2000-m rowing-ergometer trials.
Jay E. Maddock, Bill Reger-Nash, Katie Heinrich, Kevin M. Leyden, and Thomas K. Bias
The U.S. Community Guide to Preventive Services strongly recommends changes in urban design, land use and accessibility to increase physical activity. To achieve these goals, policy change is often needed. This study assessed attitudes of decision makers in Hawaii to determine if physical activity related issues are among their priorities.
State and county officials (n = 179) were mailed surveys. Respondents listed the three most important problems (open-ended) in Hawaii and rated the importance of 23 specified problems, of which six directly related to physical activity.
The survey was completed by 126 (70.4%) respondents. The most frequently mentioned categories for the open-ended questions were affordable housing, environment/sustainability, sprawl/traffic/population growth, and healthcare. Among the closed-ended physical activity related items, increasing traffic was ranked highest (43.9%) and fourth overall. Less than 12% of decision makers rated other physical activity issues as important.
Future work is needed to increase the visibility and importance of physical activity related issues among policymakers.
Mehdi Kordi, Len Parker Simpson, Kevin Thomas, Stuart Goodall, Tom Maden-Wilkinson, Campbell Menzies, and Glyn Howatson
Purpose: To assess the association between the W′ and measures of neuromuscular function relating to the capacity of skeletal muscle to produce force in a group of elite cyclists. Methods: Twenty-two athletes specializing in a range of disciplines and competing internationally volunteered to participate. Athletes completed assessments of maximum voluntary torque (MVT), voluntary activation, and isometric maximum voluntary contraction to measure rate of torque development (RTD). This was followed by assessment of peak power output (PPO) and 3-, 5-, and 12-minute time trials to determine critical power. Pearson correlation was used to examine associations with critical power and W′. Goodness of fit was calculated, and significant relationships were included in a linear stepwise regression model. Results: Significant positive relationships were evident between W′ and MVT (r = .82), PPO (r = .70), and RTD at 200 milliseconds (r = .59) but not with RTD at 50 milliseconds and voluntary activation. Correlations were also observed between critical power and RTD at 200 milliseconds and MVT (r = .54 and r = .51, respectively) but not with PPO, voluntary activation, or RTD at 50 milliseconds. The regression analysis found that 87% of the variability in W′ (F 1,18 = 68.75; P < .001) was explained by 2 variables: MVT (81%) and PPO (6%). Conclusions: It is likely that muscle size and strength, as opposed to neural factors, contribute meaningfully to W′. These data can be used to establish training methods to enhance W′ to improve cycling performance in well-trained athletes.