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Open access

Kerstin Bach, Atle Kongsvold, Hilde Bårdstu, Ellen Marie Bardal, Håkon S. Kjærnli, Sverre Herland, Aleksej Logacjov, and Paul Jarle Mork

Introduction: Accelerometer-based measurements of physical activity types are commonly used to replace self-reports. To advance the field, it is desirable that such measurements allow accurate detection of key daily physical activity types. This study aimed to evaluate the performance of a machine learning classifier for detecting sitting, standing, lying, walking, running, and cycling based on a dual versus single accelerometer setups during free-living. Methods: Twenty-two adults (mean age [SD, range] 38.7 [14.4, 25–68] years) were wearing two Axivity AX3 accelerometers positioned on the low back and thigh along with a GoPro camera positioned on the chest to record lower body movements during free-living. The labeled videos were used as ground truth for training an eXtreme Gradient Boosting classifier using window lengths of 1, 3, and 5 s. Performance of the classifier was evaluated using leave-one-out cross-validation. Results: Total recording time was ∼38 hr. Based on 5-s windowing, the overall accuracy was 96% for the dual accelerometer setup and 93% and 84% for the single thigh and back accelerometer setups, respectively. The decreased accuracy for the single accelerometer setup was due to a poor precision in detecting lying based on the thigh accelerometer recording (77%) and standing based on the back accelerometer recording (64%). Conclusion: Key daily physical activity types can be accurately detected during free-living based on dual accelerometer recording, using an eXtreme Gradient Boosting classifier. The overall accuracy decreases marginally when predictions are based on single thigh accelerometer recording, but detection of lying is poor.

Open access

Alannah K.A. McKay, Trent Stellingwerff, Ella S. Smith, David T. Martin, Iñigo Mujika, Vicky L. Goosey-Tolfrey, Jeremy Sheppard, and Louise M. Burke

Throughout the sport-science and sports-medicine literature, the term “elite” subjects might be one of the most overused and ill-defined terms. Currently, there is no common perspective or terminology to characterize the caliber and training status of an individual or cohort. This paper presents a 6-tiered Participant Classification Framework whereby all individuals across a spectrum of exercise backgrounds and athletic abilities can be classified. The Participant Classification Framework uses training volume and performance metrics to classify a participant to one of the following: Tier 0: Sedentary; Tier 1: Recreationally Active; Tier 2: Trained/Developmental; Tier 3: Highly Trained/National Level; Tier 4: Elite/International Level; or Tier 5: World Class. We suggest the Participant Classification Framework can be used to classify participants both prospectively (as part of study participant recruitment) and retrospectively (during systematic reviews and/or meta-analyses). Discussion around how the Participant Classification Framework can be tailored toward different sports, athletes, and/or events has occurred, and sport-specific examples provided. Additional nuances such as depth of sport participation, nationality differences, and gender parity within a sport are all discussed. Finally, chronological age with reference to the junior and masters athlete, as well as the Paralympic athlete, and their inclusion within the Participant Classification Framework has also been considered. It is our intention that this framework be widely implemented to systematically classify participants in research featuring exercise, sport, performance, health, and/or fitness outcomes going forward, providing the much-needed uniformity to classification practices.

Open access

Petra Lundström, Katarina Lauruschkus, Åsa Andersson, and Åsa B. Tornberg

Purpose: To investigate the acute exercise effects of dynamic standing exercise on blood glucose and blood lactate among children and adolescents with cerebral palsy who are nonambulant. Methods: Twenty-four participants with cerebral palsy who are nonambulant performed 30 minutes of dynamic standing exercise using a motorized device enabling assisted passive movements in an upright weight-bearing position. Capillary blood samples were taken from the fingertip for measurement of blood glucose and blood lactate at rest and at the end of exercise. Results: At rest, the participants had hyperlactatemia that was unaffected after exercise, presented as median and interquartile range at rest 1.8 (1.3:2.7) mmol/L, and after exercise 2.0 (1.1:2.5) mmol/L. Children and adolescents with Gross Motor Function Classification System, level V, had higher lactate levels at rest (2.5 [1.8:2.9] vs 1.4 [1.0:2.0]; P = .030) and after exercise (2.3 [2.0:2.6] vs 1.2 [0.9:2.2]; P = .032) compared with children and adolescents with Gross Motor Function Classification System, level IV, respectively. A statistically significant larger decrease in blood lactate levels after exercise was observed in children and adolescents with higher resting blood lactate levels (ρ = .56; P = .004). There were no statistically significant changes in blood glucose. Conclusions: Forty percentage of the participants had mild hyperlactatemia at rest and participants with the highest blood lactate levels at rest had the greatest decrease in blood lactate levels after one bout of exercise. Children and adolescents who were classified with the highest level of the Gross Motor Function Classification Scale had higher blood lactate levels. More studies are needed on how to prevent chronically high resting levels of lactate with exercise in children with cerebral palsy who are nonambulant.

Open access

Alanna Weisberg, Hyun Suk Lee, Tak Fung, and Larry Katz

The overhand throw is a complex whole-body motor skill that is fundamental to many sports and activities. When throwing properly, the momentum generated to complete the movement begins in the lower body and transfers through the trunk to the throwing arm. This proof-of-concept study’s primary purpose was to evaluate the impact of the nonthrowing arm on the ball speed during an overhand throw with both the dominant and nondominant arms. Eighteen participants (age: 20.20 ± 2.90 years, nine women) were divided into two intervention groups: a pulling group taught to engage the nonthrowing arm through a pull toward the body and a nonpulling group taught the overhand throw using a component-based physical education curriculum. Each participant completed 12 total throws, six for each side (dominant and nondominant arm). Ball speed and kinematic data were collected using an eight-camera motion analysis system and were assessed using a pre–post study design. The two groups showed significant improvements pre–post when throwing with both the dominant and nondominant arms. Based on effect size comparisons, engaging the nonthrowing arm makes a meaningful difference in maximal ball velocity.

Open access

Bradley J. Cardinal

Kinesiology is a field focused on physical activity and its impact on health, society, and quality of life. But do all people have equal opportunities to access and experience physical activity? Do physical activity settings allow people to freely express themselves? Are the benefits of physical activity universally shared by all people? If the answer to any of these questions is “no,” then these questions demand not only our immediate attention, but also our collective action. During the National Academy of Kinesiology’s 90th anniversary meeting, September 22–24, 2021, these questions and others were explored through presentations devoted to the theme “Kinesiology’s Social Justice Imperative.” This essay overviews the meeting, its purpose, and the organizers and introduces the 11 thematic papers in the “Proceedings of the National Academy of Kinesiology’s 2021 Meeting: Kinesiology’s Social Justice Imperative” issue, plus a 12th essay commemorating the National Academy of Kinesiology’s 90th anniversary meeting.

Open access

Precious Barnes and Matthew Rivera

Context: Active Release Technique® (ART®) is a manual therapy used for soft tissue-related issues, commonly used to lengthen structures in a shortened position and to restore motion of soft tissues. Objective: The purpose of this systematic review was to collect, appraise, and summarize the available literature, evaluating the effects of ART® on pain, range of motion (ROM), and disability. Evidence Acquisition: Electronic databases (PubMed, EBSCOhost, MEDLINE, SPORTDiscus, and CINAHL) were searched from 2000 to November 2020. The search was completed using a combination of key words related to ART®, rehabilitation, and outcomes. Search limits were full-text publications written in English. Inclusion criteria required that studies evaluated outcomes using ART® for rehabilitation, were peer reviewed, and included human participants without catastrophic conditions or injuries. The modified Downs and Black checklist for nonrandomized studies was used to assess methodological quality of identified studies by 2 independent reviewers, average scores were calculated. The level of evidence was assessed using the strength of recommendation taxonomy. Evidence Synthesis: Nine studies were inculded in this review. The average methodological quality of the studies was 12/15 and ranged from 10 to 14, with the most common methodological quality item missed being the blinding of researchers collecting outcomes. Six studies that assessed pain found significant improvements in participants’ pain levels. Six studies that assessed ROM found significant improvement in participants’ ROM. Two studies that assessed disability found significant improvement in disability. Conclusion: Evidence suggests that ART® may be beneficial in improving pain, ROM, and disability. This review found that ART® positively impacted patient outcomes and may be a viable treatment option for clinicians treating musculoskeletal conditions. However, further research is necessary to determine optimal dosage and long-term effects of ART® on these patient outcomes.

Open access

Wojtek Chodzko-Zajko, Debra J. Rose, Diane E. Whaley, Philip D. Chilibeck, and Samuel R. Nyman