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Collegiate- and elite-level swimmers can see extraordinary volumes in training throughout a season. Consequentially, injury and dysfunction in the shoulder are common in competitive swimmers. This study investigated whether preseason Kerlan-Jobe Orthopedic Clinic Questionnaire scores could identify collegiate swimmers who sustained a shoulder injury during an athletic season. A Kerlan-Jobe Orthopedic Clinic Questionnaire score of ≥81 was able to identify swimmers who did not sustain an injury versus those who did. The receiver operating characteristics demonstrated an area under the curve of 0.820, p

Context: Bodyweight-supporting treadmills are popular rehabilitation tools for athletes recovering from impact-related injuries because they reduce ground reaction forces during running. However, the overall metabolic demand of a given running speed is also reduced, meaning athletes who return to competition after using such a device in rehabilitation may not be as fit as they had been prior to their injury. Objective: To explore the metabolic effects of adding incline during bodyweight-supported treadmill running. Design: Cross-sectional. Setting: Research laboratory. Participants: Fourteen apparently healthy, recreational runners (6 females and 8 males; 21 [3] y, 1.71 [0.08] m, 63.11 [6.86] kg). Interventions: The participants performed steady-state running trials on a bodyweight-supporting treadmill at 8.5 mph. The control condition was no incline and no bodyweight support. All experimental conditions were at 30% bodyweight support. The participants began the sequence of experimental conditions at 0% incline; this increased to 1%, and from there on, 2% incline increases were introduced until a 15% grade was reached. Repeated-measures analysis of variance was used to compare all bodyweight-support conditions against the control condition. Main Outcome Measures: Oxygen consumption, heart rate, and rating of perceived exertion. Results: Level running with 30% bodyweight support reduced oxygen consumption by 21.6% (P P P Conclusions: Athletes can maintain training intensity while running on a bodyweight-supporting treadmill by introducing incline. Rehabilitation programs should rely on quantitative rather than qualitative data to drive exercise prescription in this modality.

Context: A variety of gait retraining interventions are available to modify running mechanics associated with musculoskeletal injuries. These often require specialized equipment and/or personnel to prompt the runner toward specific strategies. Objective: To determine whether instructing female recreational runners to “run quietly” could decrease impact force characteristics. Design: Cohort. Setting: Research laboratory. Participants: Fifteen healthy female recreational runners (24 [7] y) volunteered. Interventions: Baseline testing occurred on day 1 (baseline), a posttraining assessment occurred on day 2 (training), and a final assessment occurred 1 week after training on day 3 (follow-up). A smartphone decibel measuring app was used to provide biofeedback on the decibel level of foot strike on day 2 (training). Main Outcomes: Peak vertical force, impact transient, peak and average vertical loading rate, ground contact time, and running economy were collected on each day and compared via repeated-measures analyses of variance. Results: Vertical ground reaction force was lower at follow-up (2.30 bodyweights [BW]) versus baseline (2.39 BW, P = .023) and training (2.34 BW, P = .047). Maximal loading rate decreased from baseline (69.70 BW·s−1) to training (62.24 BW·s−1, P = .021) and follow-up (60.35 BW·s−1, P = .031). There was no change in running economy. Conclusions: Our findings demonstrate that simple instructions to “run quietly” can yield immediate and sustained reductions in impact force profiles, which do not influence running economy.

Context: Previous work has demonstrated an improvement in running economy during sustained running on a lower body positive pressure treadmill, but neuromuscular and spatiotemporal measures have only been investigated during short-duration running bouts on these devices. The current study sought to replicate the noted metabolic response and investigate whether neuromuscular and/or spatiotemporal adaptations underlie the noted improvements in running economy. Design: Cross-sectional. Methods: Fifteen trained runners (11 males and 4 females) ran three 15-minute trials with 30% bodyweight support at 70% of the speed that elicited their peak oxygen consumption while running on a standard treadmill. A series of 1-way analyses of variance with repeated measures were used to explore differences in dependent variables over the 45 minutes of running. Dependent variables included oxygen consumption, root-mean-square electromyography of the vastus medialis and medial gastrocnemius during stance, and spatiotemporal parameters. Results: Oxygen consumption decreased after the initial exposure, with no further reductions after 20 minutes. Root-mean-square electromyography of the vastus medialis and medial gastrocnemius also decreased over time, with no further reductions after 20 and 10 minutes, respectively. No differences in spatiotemporal parameters were found. Conclusions: Future research should provide sufficient time for runners to develop a more economical gait pattern prior to collecting dependent variables, and previous findings using lower body positive pressure treadmills may need to be reconsidered. Athletes using these devices for training or rehabilitation should note that increased economy will lower the intensity of a given treadmill setting over time.

Physical activity (PA) in the United States progressively continues to decline despite research highlighting the importance of an active lifestyle. Particularly, recommended levels of PA are associated with reduced risk for a large number of negative, yet preventable health conditions in apparently healthy populations. Unfortunately, individuals who report having one or more disabilities perform far less PA than their apparently healthy counterparts. While technological advancements such as wearable devices to monitor PA have become popular, few studies have evaluated the effectiveness of wearable technology-based interventions on increasing PA levels and improving health outcomes in college students and individuals with disabilities. Thus, the purposes of this investigation were (1) to evaluate if providing a Fitbit PA tracking device to college students with disabilities would increase PA and improve health outcomes such as cardiovascular (CV) fitness and body composition, and (2) to investigate whether the addition of health education sessions would provide additional benefits. A total of 24 participants (27 ± 7 years) were given a Fitbit and had their PA monitored over twelve weeks. Group randomization was conducted where one group received only the Fitbit (FO) and a second group where participants also received health education sessions (E+F). Pre and post physiological assessments were also conducted. No significant group*time interactions were observed. Significant increases in mean treadmill duration and VO2peak occurred from pre to post. Mean daily steps in the E+F group were significantly higher than the FO group (8134 ± 441 vs. 7581 ± 577, respectively). Twelve weeks of Fitbit usage was effective in increasing CV fitness in individuals who identified as having one or more disabilities. Considering the lack of a significant improvement in health outcomes by the addition of educational programming the use of a Fitbit alone may be sufficient to improve CV fitness in this population.

A sedentary lifestyle is a key contributor to chronic disease, and many occupations in our society are sedentary in nature. Therefore, a main focus of workplace health promotion programs is to increase employee physical activity. In addition, workplaces are an ideal arena to deliver health programming, however many organizations face barriers to implementation, such as staffing, budget and time constraints. The purpose of this case study is to present a real world, cost-effective workplace walking program that positively impacted employee health. Feedback will also be provided on challenges encountered in relation to compliance and retention. Finally, practical, and social applications are discussed.

Subjective evaluations of balance performance, like the modified Balance Error Scoring System (mBESS), are highly popular. Alternatively, quantitative measures may offer additional clarity in identifying balance dysfunction. A novel measure to define balance impairments is time to boundary (TTB), which represents the amount of time available to make corrective postural adjustments prior to the centre of pressure (CoP) reaching the edge of the base of support. The purpose of this investigation was to assess TTB and traditional measures of CoP displacement of young adults performing the mBESS on a BTrackS balance plate. Path length and TTB were calculated in anterior-posterior (AP) and medio-lateral (ML) directions, respectively. AP and ML path lengths were largest in Single stance (109.2118.1 cm, respectively) and smallest in Dual stance (27.136.4 cm, respectively). The average AP and ML TTBs were higher in Dual (10.677.27 s, respectively) compared to Single (3.541.20 s, respectively) or Tandem (10.111.94 s, respectively) stances, and lower in Single stance compared to Tandem. Given the effect sizes for TTB were greater than those of path length in both directions, TTB more adequately differentiates these stance conditions than path length or subjective scores.

Background Some comparisons between walking gait of obese and non-obese adults have been made during barefoot conditions, and others while shod. Methodological differences, footwear conditions, and gait speed disparities among the research done on overweight individuals were the factors motivating the present study. Research question The present study was designed to compare gait kinematics and kinetics of obese adults between two footwear conditions (barefoot versus shod) at a set walking speed. Methods Ten obese (body mass index > 30 kg.m−2), but otherwise healthy adults (age = 26 ± 3 years, height = 1.79 ± 0.10 m, mass = 108.46 ± 13.25 kg) participated in this study. Ground reaction forces and 3D kinematic data were simultaneously collected as participants walked overground at 1.5 m.s−1 in barefoot and shod conditions. Results Walking barefoot reduced ankle, knee, and hip ranges of motion, and stride length, stance time, and double support time were also reduced. Kinetic outcomes included smaller peak vertical and anterior-posterior ground reaction forces and knee joint moments while barefoot. Significance Footwear condition significantly influences key gait variables in obese adults. Conflicting conclusions from previous investigations of gait in obese adults may be a consequence of differing footwear conditions.

Balance is a complex, sensorimotor task requiring an individual to maintain the center of gravity within the base of support. Quantifying balance in a reliable and valid manner is essential to evaluating disease progression, aging complications, and injuries in clinical and research settings. Typically, researchers use force plates to track motion of the center of gravity during a variety of tasks. However, limiting factors such as cost, portability, and availability have hindered postural stability evaluation in these settings. This study compared the "gold standard" for assessing postural stability (i.e., the laboratory-grade force plate) to a more affordable and portable assessment tool (i.e., BTrackS balance plate) in healthy young adults. Correlations and Bland-Altman plots between the center of pressure outcome measures derived from these two instruments were produced. Based on the results of this study, the measures attained from the portable balance plate objectively quantified postural stability with high validity on both rigid and compliant surfaces, demonstrated by thirty-five out of thirty-eight observed postural stability metrics in both surface conditions with a correlation of 0.98 or greater. The low cost, portable system performed similarly to the lab-grade force plate indicating the potential for practitioners and researchers to use the BTrackS balance plate as an alternative to the more expensive force plate option for assessing postural stability, whether in the lab setting or in the field.

Gait data are commonly presented as an average of many trials or as an average across participants. Discrete data points (eg, maxima or minima) are identified and used as dependent variables in subsequent statistical analyses. However, the approach used for obtaining average data from multiple trials is inconsistent and unclear in the biomechanics literature. This study compared the statistical outcomes of averaging peaks from multiple trials versus identifying a single peak from an average profile. A series of paired-samples t tests were used to determine whether there were differences in average dependent variables from these 2 methods. Identifying a peak value from the average profile resulted in significantly smaller magnitudes of dependent variables than when peaks from multiple trials were averaged. Disagreement between the 2 methods was due to temporal differences in trial peak locations. Sine curves generated in MATLAB confirmed this misrepresentation of trial peaks in the average profile when a phase shift was introduced. Based on these results, averaging individual trial peaks represents the actual data better than choosing a peak from an average trial profile.