Relative leg press strength relates to activity energy expenditure in older women: Implications for exercise prescription.

Limited work has evaluated how leg press strength (LPS), relative to body mass (i.e., rLPS), affects heart rate (HR) responses during activities of daily living. Such information would prove useful by informing a specific level of rLPS needed to promote independent mobility and physical activity. Secondary analyses were performed on baseline measures of 76 untrained older (65 ± 4 y) women. After familiarization, one-repetition maximum leg press was converted to rLPS by dividing the external load lifted (kg) by body mass (BM). Participants were stratified according to percentile of age-group norms of rLPS: ≤50 % (low, ≤0.99 kg/BM, n = 15), 51-89 % (middle, 1.0-1.31 kg/BM, n = 31), and ≥90 % (high, ≥1.32 kg/BM, n = 30). HR was measured at rest and during laboratory-based tasks including fixed-speed (0.89 m·s-1) non-graded treadmill walking, graded (2.5 %) treadmill walking, and stair stepping. Maximal oxygen uptake (V̇O2max) was measured via indirect calorimetry. Doubly labeled water was used to quantify activity energy expenditure (AEE) over a 14-d period. Relative LPS per group were: 0.85 ± 0.12 (low), 1.16 ± 0.09 (middle), and 1.55 ± 0.25 (high) (p < 0.001). Significant between-group differences in HR emerged during both walking tasks and stair stepping - with the high rLPS group having the lowest HR. AEE between-group comparisons did not yield statistical significance (p = 0.084), however, rLPS correlated with AEE (r = 0.234, p = 0.042) and V̇O2max (r = 0.430, p < 0.001). Such findings suggest a higher rLPS attenuates HR for weight-bearing activities while also demonstrating a significant, albeit modest, positive link to AEE among older women. This information may be especially relevant for informing thresholds of rLPS linked to mobility and functional independence in older women.

A Novel Approach to Assessment of Perceptual-Motor Efficiency and Training-Induced Improvement in the Performance Capabilities of Elite Athletes.

Standard clinical assessments of mild traumatic brain injury are inadequate to detect subtle abnormalities that can be revealed by sophisticated diagnostic technology. An association has been observed between sport-related concussion (SRC) and subsequent musculoskeletal injury, but the underlying neurophysiological mechanism is not currently understood. A cohort of 16 elite athletes (10 male, 6 female), which included nine individuals who reported a history of SRC (5 male, 4 female) that occurred between 4 months and 8 years earlier, volunteered to participate in a 12-session program for assessment and training of perceptual-motor efficiency. Performance metrics derived from single- and dual-task whole-body lateral and diagonal reactive movements to virtual reality targets in left and right directions were analyzed separately and combined in various ways to create composite representations of global function. Intra-individual variability across performance domains demonstrated very good SRC history classification accuracy for the earliest 3-session phase of the program (Reaction Time Dispersion AUC = 0.841; Deceleration Dispersion AUC = 0.810; Reaction Time Discrepancy AUC = 0.825, Deceleration Discrepancy AUC = 0.794). Good earliest phase discrimination was also found for Composite Asymmetry between left and right movement directions (AUC = 0.778) and Excursion Average distance beyond the minimal body displacement necessary for virtual target deactivation (AUC = 0.730). Sensitivity derived from Youden's Index for the 6 global factors ranged from 67 to 89% and an identical specificity value of 86% for all of them. Median values demonstrated substantial improvement from the first 3-session phase to the last 3-session phase for Composite Asymmetry and Excursion Average. The results suggest that a Composite Asymmetry value ≥ 0.15 and an Excursion Average value ≥ 7 m, provide reasonable qualitative approximations for clinical identification of suboptimal perceptual-motor performance. Despite acknowledged study limitations, the findings support a hypothesized relationship between whole-body reactive agility performance and functional connectivity among brain networks subserving sensory perception, cognitive decision-making, and motor execution. A complex systems approach appears to perform better than traditional data analysis methods for detection of subtle perceptual-motor impairment, which has the potential to advance both clinical management of SRC and training for performance enhancement.

Exercise load monitoring: integrated approaches to advance the individualisation of exercise oncology.

Whether slowing disease progression or combatting the ills of advancing age, the extensive utility of exercise training has contributed to the outright declaration by the American College of Sports Medicine that 'exercise is medicine'. Consistent with general framework of adaptation, the advantages of exercise training are indiscriminate-benefitting even the most susceptible clinical populations. Still, the benefit of exercise training presupposes healthy adaptation wherein progressive overload matches sufficient recovery. Indeed, a difference exists between healthy adaptation and non-functional over-reaching (ie, when internal/external load exceeds recovery capacity)-a difference that may be blurred by cancer treatment and/or comorbidity. Recent advances in smartwatches make them ideally suited to non-invasively monitor the physiological stresses to exercise training. Resolving whether individuals are successfully adapting to exercise training via load monitoring bears clinical and practical relevance. While behaviour-change research aims to identify positive constructs of exercise adherence, further attention is needed to uncover how to optimise exercise prescription among cancer populations. Herein, we briefly discuss the constituents of exercise load monitoring, present examples of internal and external load and consider how such practices can be applied to cancer populations.

Upper-Extremity Perceptual-Motor Training Improves Whole-Body Reactive Agility Among Elite Athletes With History of Sport-Related Concussion.

CONTEXT: Sport-related concussion (SRC) elevates risk for subsequent injury, which may relate to impaired perceptual-motor processes that are potentially modifiable. OBJECTIVE: To assess a possible upper-extremity (UE) training effect on whole-body (WB) reactive agility performance among elite athletes with history of SRC (HxSRC) and without such history of SRC. DESIGN: Cohort study. SETTING: Residential training center. PARTICIPANTS: Elite athletes (12 males and 8 females), including 10 HxSRC and 10 without such history of SRC. INTERVENTION: One-minute training sessions completed 2 to 3 times per week over a 3-week period involved verbal identification of center arrow direction for 10 incongruent and 10 congruent flanker test trials with simultaneous reaching responses to deactivate illuminated buttons. MAIN OUTCOME MEASURES: Pretraining and posttraining assessments of UE and WB reactive responses included flanker test conflict effect (incongruent minus congruent reaction time) and WB lateral average asymmetry derived from reaction time, speed, acceleration, and deceleration in opposite directions. Discrimination was assessed by receiver operating characteristic analysis, and training effect was assessed by repeated-measures analysis of variance. RESULTS: Pretraining discrimination between HxSRC and without such history of SRC was greatest for conflict effect ≥80 milliseconds and WB lateral average asymmetry ≥18%. Each athlete completed 6 training sessions, which improved UE mean reaction time from 767 to 646 milliseconds (P < .001) and reduced mean conflict effect from 96 to 53 milliseconds (P = .039). A significant group × trial interaction was evident for WB lateral average asymmetry (P = .004), which was reduced from 24.3% to 12.5% among those with HxSRC. CONCLUSIONS: Suboptimal perceptual-motor performance may represent a subtle long-term effect of concussion that is modifiable through UE training, which appears to improve WB reactive capabilities.

Concussion History and Neuromechanical Responsiveness Asymmetry.

CONTEXT: Detection of subtle changes in brain sensorimotor processes may enable clinicians to identify athletes who would derive the greatest benefit from interventions designed to reduce the risk for future injury and progressive neurologic or musculoskeletal dysfunction. OBJECTIVE: To develop a generalizable statistical model for identifying athletes who possess subtle alterations in sensorimotor processes that may be due to previous concussion. DESIGN: Cross-sectional study. SETTING: Residential Olympic Training Center sports medicine clinic. PATIENTS OR OTHER PARTICIPANTS: A primary cohort of 35 elite athletes and a secondary cohort of 40 elite athletes who performed identical tests the preceding year. INTERVENTION(S): Two upper extremity tests of visual-motor reaction time and 2 tests of whole-body reactive agility were administered. The whole-body tests required lateral or diagonal responses to virtual-reality targets, which provided measures of reaction time, speed, acceleration, and deceleration. MAIN OUTCOME MEASURE(S): Sport-related concussion history, which was reported by 54% (n = 19) of the athletes in the primary cohort and 45% (n = 18) of the athletes in the secondary cohort. RESULTS: Univariable analyses identified 12 strong predictors of sport-related concussion history, which we combined to create a composite metric with maximum predictive value. Composite lateral asymmetry for whole-body reactive movements and persisting effects of previous musculoskeletal injury yielded a logistic regression model with exceptionally good discrimination (area under the curve = 0.845) and calibration (predicted-observed probabilities within 7 subgroups: r = 0.959, P = .001). Application of the derived model to compatible data acquired from another cohort of elite athletes demonstrated very good discrimination (area under the curve = 0.772) and calibration (within 8 subgroups: r = 0.849, P = .008). CONCLUSIONS: Asymmetry in whole-body reactive movement capabilities may be a manifestation of a subtle abnormality in the functional connectivity of brain networks that might be relevant to previously reported associations between sport-related concussion history and musculoskeletal injury occurrence.

Survey of Income Comparison: General Practice and Sports Certified Doctors of Chiropractic.

OBJECTIVE: The purpose of this study was to determine whether there are differences in reported gross billings and collections between doctors of chiropractic who have obtained a certificate of additional qualification (CAQ) in sports medicine compared with those without a CAQ in sports medicine. METHODS: A cross-sectional study was conducted. An e-mail invitation to participate in an anonymous survey was sent to doctors of chiropractic who hold active certifications with the American Chiropractic Board of Sports Physicians. The respondents were provided a link to a web-based survey that was constructed with similar questions to a national chiropractic survey issued by Chiropractic Economics (CE) for the same year (2015). RESULTS: Three hundred forty-nine sports medicine CAQ doctors of chiropractic responded (23.8% response rate) in comparison to 719 CE respondents. The CAQ respondents averaged $722 983 in gross billings (9.8% response rate) compared with $539 046 by CE respondents. Sports medicine CAQ doctors of chiropractic averaged $452 376 in gross collections (10.4% response rate) compared with $348 773 by CE respondents. CONCLUSION: An analysis of these 2 surveys illustrates that CAQ respondents report higher total annual gross billings and collections than the CE respondents. Improving study methodology may improve response rates and garner a more accurate representation of any differences between doctors of chiropractic with and without CAQs.

Detection of Persisting Concussion Effects on Neuromechanical Responsiveness.

PURPOSE: Assessment of various indices of neuromechanical responsiveness for association with concussion history. METHODS: An observational cohort study included 48 elite athletes (34 males: 23.8 ± 4.4 yr; 14 females: 25.4 ± 4.5 yr) who performed visuomotor reaction time (VMRT) tests involving rapid manual contact with illuminated target buttons that included two dual-task conditions: 1) simultaneous oral recitation of scrolling text (VMRT+ST) and 2) simultaneous verbal responses to identify the right or left direction indicated by the center arrow of the Eriksen flanker test (VMRT+FT). A whole-body reactive agility (WBRA) test requiring side-shuffle movements in response to visual targets was used to assess reaction time, speed, acceleration, and deceleration. RESULTS: Concussion occurrence at 2.0 ± 2.3 yr before testing was reported by 21 athletes. Strong univariable associations were found for VMRT+FT left minus right difference ≥15 ms (odds ratio [OR], 7.14), VMRT+ST outer two-ring to inner three-ring ratio ≥1.28 (OR, 4.58), and WBRA speed asymmetry ≥7.7% (OR, 4.67). A large VMRT+FT by VMRT+ST interaction effect was identified (OR, 25.00). Recursive partitioning identified a three-way VMRT+FT by VMRT+ST by WBRA interaction that had 100% positive predictive value for identification of athletes with concussion history, whereas negative status on all three factors had 90% negative predictive value. CONCLUSIONS: Performance on dual-task VMRT tests and the WBRA test identified neuromechanical responsiveness deficiencies among elite athletes who reported a history of concussion.

Subspine Hip Impingement: An Unusual Cause of Hip Pain in an Elite Weightlifter.

Anterior hip pain can be difficult to diagnose due to the many pathologies and overlapping pain patterns that exist in the hip region. Clinical findings of pain at the anterior inferior iliac spine with passive hip flexion, proximal quadriceps pain and weakness, and painful impingement tests of the hip may be indicative of subspine hip impingement. This report describes the diagnosis and treatment of anterior hip pain, including subspine impingement and femoroacetabular impingement in an elite weightlifter. This case also describes how with the correct diagnosis and treatment, the athlete returned to play to her previous level of sport 11 months after a complex hip injury.

Laboratory Tests Ordered By a Chiropractic Sports Physician on Elite Athletes Over a 1-Year Period.

OBJECTIVE: The purpose of this study is to describe and discuss laboratory tests ordered on elite athletes in an interdisciplinary sports medicine clinic by a doctor of chiropractic over 1 calendar year. METHODS: A retrospective review of laboratory tests ordered during routine clinical practice as standard screening and diagnostic tests from November 1, 2009, to November 1, 2010 was performed. Data were collected during clinical encounters at one sports medicine clinic and entered into a database for analysis. Descriptive and frequency statistics were used to describe the tests ordered and the frequency of abnormal findings. RESULTS: Five hundred and thirty-nine studies were ordered for diagnostic and routine screenings on 137 athlete patients (86 males, 51 females), representing 49 types of tests. Sample sources included blood, urine, skin lesions, and fecal matter. The most commonly ordered tests were complete blood count, comprehensive metabolic panel, serum ferritin, creatine kinase, serum iron and total iron binding capacity, total cortisol, thyroid stimulating hormone, and lipid panels. There were 217 studies (40%) flagged as abnormal by the reporting laboratory. CONCLUSION: This report provides greater insight into the diverse array of laboratory studies ordered over a 1-year period for diagnosis and screening of elite athletes. A high percentage of the results were flagged as abnormal by the laboratory. These findings show that the unique physiology of the elite athlete must be considered when interpreting laboratory findings in this population.

Sport Concussion Knowledge and Clinical Practices: A Survey of Doctors of Chiropractic With Sports Certification.

OBJECTIVE: The purpose of this study is to describe the knowledge base and clinical practices regarding concussion by sports-certified doctors of chiropractic. METHODS: A 21-item survey was distributed to the 312 attendees of the 2014 American Chiropractic Board of Sports Physicians Sports Sciences Symposium. Results were measured by frequency analysis and descriptive statistics for all surveys completed by sports-certified chiropractors. RESULTS: Seventy-six surveys were returned by sports-certified doctors of chiropractic. All (N = 76) 100% of respondents believe that the evaluation of concussion should be performed by a health care provider with training in concussion. The respondents actively assess and manage concussion in adults (96%), adolescents (95%), and children (75%). A majority (79%) of respondents believe that the Sideline Concussion Assessment Tool-3 represents a current standard of care for the sideline evaluation of the athlete who possibly has sustained a sport concussion. Most respondents agreed or strongly agreed that manual therapies may be appropriate in certain circumstances in adults (80%) and minors (80%). CONCLUSION: This cross section of certified sports chiropractors strongly believes that the evaluation of concussion should be performed by a health care provider with specific training in concussion. A high percentage of the sports-certified chiropractors who responded assess and manage sport concussion in their practice, and many of them endorse the use of the Sideline Concussion Assessment Tool-3 as a sideline assessment tool.

The American Chiropractic Board of Sports Physicians Position Statement on Pre-Participation Examinations: An Expert Consensus.

OBJECTIVE: The purpose of this paper is to present a position statement of best practices for the provision of a safe and high-quality pre-participation examination (PPE) and to provide recommendations on education requirements for doctors of chiropractic providing the PPE. METHODS: In 2014, the American Chiropractic Board of Sports Physicians (ACBSP) Board of Directors identified a need to review and update the ACBSP position statements and practice guidelines in order to be current with evolving best practices. Twelve ACBSP certificants, 10 Diplomates of the ACBSP, and 2 Certified Chiropractic Sports Physicians, met in April 2015 to author a pre-participation position statement using an expert consensus process. Panel members excluded anyone with commercial conflicts of interest and included individuals with expertise in clinical sports medicine and the performance of PPEs. A literature review was performed and circulated in advance for use by the panel in addressing the topic. The position statement was written through a consensus process and accepted by the ACBSP Board of Directors in May of 2015. RESULTS: The ACBSP Position Statement on Pre-participation Examinations identifies the qualifications and best practices for doctors of chiropractic to perform a PPE. CONCLUSION: This position statement states that doctors of chiropractic with post graduate education and current Diplomates of the ACBSP or Certified Chiropractic Sports Physicians certification have the prerequisite education and qualifying skills to perform PPEs.

Development of the 2012 American Chiropractic Board of Sports Physicians position statement on concussion in athletics.

OBJECTIVE: The purpose of this article is to provide a summary of the development of the American Chiropractic Board of Sports Physicians (ACBSP) Position Statement on Concussion in Athletics regarding the management of concussion in sport and to offer suggestions to qualifying doctors of chiropractic (DCs) to make return-to-play decisions and clarify common concepts pertaining to evaluating and managing concussion in sport. METHODS: A literature review of position statements from sports medicine organizations was performed. The authors reviewed each statement for content. Key issues in the management of concussion in sport were identified with special consideration to concussion management by DCs. A position statement on the management of concussion in sport was drafted by the authors and submitted to the Board of Directors of the ACBSP for review. The Board of Directors called for minor revision; and after all revisions were made, the document was resubmitted. The Board of Directors of the ACBSP accepted the document for publication and presentation. The document was presented and disseminated to certificants by the ACBSP at the 2011 Chiropractic Sports Sciences Symposium. RESULTS: The 2012 ACBSP Position Statement on Concussion in Athletics was accepted by the ACBSP Board of Directors. CONCLUSION: The Position Statement on Concussion in Athletics has been accepted by the ACBSP. This document offers guidance on the management of concussion in sport and provides qualifying DCs information to make return-to-play decisions.