Accelerometer techniques for capturing human movement validated against direct observation: a scoping review.

INTRODUCTION: Accelerometers are devices commonly used to measure human physical activity and sedentary time. Accelerometer capabilities and analytical techniques have evolved rapidly, making it difficult for researchers to keep track of advances and best practices for data processing and analysis. OBJECTIVE: The objective of this scoping review is to determine the existing methods for analyzing accelerometer data for capturing human movement which have been validated against the criterion measure of direct observation. METHODS: This scoping review searched 14 academic and 5 grey databases. Two independent raters screened by title and abstract, then full text. Data were extracted using Microsoft Excel and checked by an independent reviewer. RESULTS: The search yielded 1039 papers and the final analysis included 115 papers. 71 unique accelerometer models were used across a total of 4217 participants. While all studies underwent validation from direct observation, most direct observation occurred live (55%) or using recordings (42%). Analysis techniques included machine learning approaches (22%), the use of existing cut-points (18%), ROC curves to determine cut-points (14%), and other strategies including regressions and non-machine learning algorithms (8%). DISCUSSION: Machine learning techniques are becoming more prevalent and are often used for activity identification. Cut-point methods are still frequently used. Activity intensity is the most assessed activity outcome; however, both the analyses and outcomes assessed vary by wear location. CONCLUSIONS: This scoping review provides a comprehensive overview of accelerometer analysis and validation techniques using direct observation and is a useful tool for researchers using accelerometers.

Prevalence of sarcopenia indicators and sub-optimal protein intake among elective total joint replacement patients.

Sarcopenia is associated with falls, and can complicate recovery following total joint replacement (TJR) surgery. We examined (1) the prevalence of sarcopenia indicators and lower-than-recommended protein intake among TJR patients and non-TJR community participants and (2) the relationships between dietary protein intake and sarcopenia indicators. We recruited adults ≥65 years of age who were undergoing TJR, and adults from the community not undergoing TJR (controls). We assessed grip strength and appendicular lean soft-tissue mass (ALSTMBMI) using DXA, and applied the original Foundation for the National Institutes of Health Sarcopenia Project cut-points for sarcopenia indicators (grip strength <26 kg for men and <16 kg for women; ALSTM <0.789 m2 for men and <0.512 m2 for women) and less conservative cut-points (grip strength <31.83 kg for men and <19.99 kg for women; ALSTM <0.725 m2 for men and <0.591 m2 for women). Total daily and per meal protein intakes were derived from 5-day diet records. Sixty-seven participants (30 TJR, 37 controls) were enrolled. Using less conservative cut-points for sarcopenia, more control participants were weak compared with TJR participants (46% versus 23%, p = 0.055), and more TJR participants had low ALSTMBMI (40% versus 13%, p = 0.013). Approximately 70% of controls and 76% of TJR participants consumed <1.2 g protein/kg/day (p = 0.559). Total daily dietary protein intake was positively associated with grip strength (r = 0.44, p = 0.001) and ALSTMBMI (r = 0.29, p = 0.03). Using less conservative cut-points, low ALSTMBMI, but not weakness, was more common in TJR patients. Both groups may benefit from a dietary intervention to increase protein intake, which may improve surgical outcomes in TJR patients.

Parental-leave policies and perceptions of pregnancy during surgical residency training in North America: a scoping review.

BACKGROUND: The number of surgical residents experiencing childbearing during residency training is increasing, and there is an absence of clarity with respect to parental-leave, lactation and return-to-work policies in support of residents. The aim of this review was to examine parental-leave policies during residency training in surgery and the perceptions of these policies by residents, program directors and coresidents, as described in the literature. METHODS: We performed a scoping review of the literature based on the following themes: maternity or parental-leave policies; antepartum work-restriction policies and obstetric complications; accommodations for training absences; support for, and perceptions of, maternity or parental leave during residency training; and challenges upon return to work, namely resident performance and breastfeeding. RESULTS: Parental-leave policies during surgical residency training have historically lacked clarity and enforcement. Although recommendations for parental leave are now in place, this may have historically contributed to a lack of perceived support for surgical residents and may result in variable leave permitted to residents. Unclear policies may also contribute to career dissatisfaction among resident parents, which may deter qualified individuals from selecting surgical subspecialties. CONCLUSION: A call for a cultural shift is required to inform policies that would better support residents across all surgical specialties to pursue success in their dual roles as parents and surgeons. With increased awareness, progress in policy and guideline development is under way.

Supplementation with the Leucine Metabolite ß-hydroxy-ß-methylbutyrate (HMB) does not Improve Resistance Exercise-Induced Changes in Body Composition or Strength in Young Subjects: A Systematic Review and Meta-Analysis.

ß-hydroxy-ß-methylbutyrate (HMB) is a leucine metabolite that is purported to increase fat-free mass (FFM) gain and performance in response to resistance exercise training (RET). The aim of this systematic review and meta-analysis was to determine the efficacy of HMB supplementation in augmenting FFM and strength gains during RET in young adults. Outcomes investigated were: total body mass (TBM), FFM, fat mass (FM), total single repetition maximum (1RM), bench press (BP) 1RM, and lower body (LwB) 1RM. Databases consulted were: Medical Literature Analysis and Retrieval System Online (Medline), Excerpta Medica database (Embase), The Cumulative Index to Nursing and Allied Health Literature (CINAHL), and SportDiscus. Fourteen studies fit the inclusion criteria; however, 11 were analyzed after data extraction and funnel plot analysis exclusion. A total of 302 participants (18-45 y) were included in body mass and composition analysis, and 248 were included in the strength analysis. A significant effect was found on TBM. However, there were no significant effects for FFM, FM, or strength outcomes. We conclude that HMB produces a small effect on TBM gain, but this effect does not translate into significantly greater increases in FFM, strength or decreases in FM during periods of RET. Our findings do not support the use of HMB aiming at improvement of body composition or strength with RET.

Equivalent Hypertrophy and Strength Gains in ß-Hydroxy-ß-Methylbutyrate- or Leucine-supplemented Men.

Ingestion of proteins with high leucine content during resistance training (RT) can augment hypertrophy. Some data suggest that a leucine metabolite, ß-hydroxy, ß-methylbutyrate (HMB), is substantially more anabolically efficacious than leucine. PURPOSE: We aimed to test whether supplementation with HMB versus leucine, added to whey protein, would result in differential muscle hypertrophy and strength gains in young men performing RT. METHODS: Twenty-six resistance-trained men (23 ± 2 yr) performed 12 wk of RT with three phases. Phase 1: 8 wk of periodized RT (three training sessions per week). Phase 2: 2 wk overreaching period (five sessions per week). Phase 3: 2 wk taper (three sessions per week). Participants were randomly assigned to twice daily ingestion of: whey protein (25 g) plus HMB (1.5 g) (whey+HMB; n = 13) or whey protein (25 g) plus leucine (1.5 g) (whey+leu; n = 13). Skeletal muscle biopsies were performed before and after RT. Measures of fat- and bone-free mass, vastus lateralis (VL) muscle thickness and muscle cross-sectional area (CSA) (both by ultrasound), muscle fiber CSA, and 1-repetition maximum (1-RM) strength tests were determined. RESULTS: We observed increases in fat- and bone-free mass, VL muscle thickness, muscle CSA and fiber type CSA and 1-RM strength with no differences between groups at any phase. We observed no differences between groups or time-group interactions in hormone concentrations at any phase of the RT program. CONCLUSIONS: ß-Hydroxy-ß-methylbutyrate added to whey did not result in greater increases in any measure of muscle mass, strength, or hormonal concentration compared to leucine added to whey. Our results show that HMB is no more effective in stimulating RT-induced hypertrophy and strength gains than leucine.