Stair-climbing Performance Research Articles

The impact of inter-limb leg lean tissue mass asymmetry on stair climb performance in career firefighters

The purpose of this study was to examine the influence of inter-limb leg lean tissue mass (LTM) asymmetry on stair climb (SC) performance in firefighters. Forty-one career firefighters (age = 32.3 ± 8.2 years, body mass = 92.1 ± 18.6 kg, stature = 178.3 ± 7.9 cm) visited the laboratory on one occasion and completed a whole body and leg composition assessment followed by a timed and weighted SC task. Percent body fat (%BF) and leg LTM were determined during a DEXA scan and regional thigh analysis. Asymmetry was assessed by the percent difference between limbs (dominant limb LTM – non-dominant limb LTM)/dominant limb LTM × 100) and a ± 3% cut-off for asymmetry classification. Participants ascended and descended 26 stairs four times as quickly as possible while wearing a weighted (22 kg) vest. Point biserial correlations were used to assess the relationship of inter-limb leg LTM asymmetry and SC performance before and after controlling for age and %BF. Results indicated that inter-limb leg LTM asymmetry was associated with longer SC task time (poorer performance) both before (r = 0.432, P = 0.005) and after (r = 0.502, P = 0.001) controlling for age and %BF. Our findings indicated that inter-limb leg LTM asymmetry negatively impacts firefighter SC performance, which may be improved with appropriate exercise interventions.

Minimal power required to ascend a flight of stairs versus actual power measured with body-fixed sensors in adults aged 19-85 years.

A good stair-climbing (SC) ability is crucial for independent living in older adults. A simple formula that estimates the mean power needed to ascend a flight of stairs in a predetermined time (i.e., total ascent duration) is easy to implement in practice, but lacks information on actual power values generated per step. The latter is possible with body-fixed sensors. This study aimed at comparing both methodologies and investigating their sensitivity to detect age-related differences. 318 participants (162 ♀; age 19-85 years) were tested on a 6-step staircase and two methodologies were used to estimate mean SC power: (1) a body-fixed sensor with automated detection of power production per step, and (2) a mathematic equation based on timed ascent duration, body mass and stair height. SC power was 210.4 W lower with formula compared to sensor, lower in women versus men and in older versus young adults (p < 0.001). The difference in SC power between sensor and formula was greater in individuals with better performance (i.e., men and young adults) (p < 0.001), indicating a ceiling effect of the formula in well-functioning and younger individuals. Likewise, ICC's between both methodologies showed poor reliability in people aged <65 years (0.087-0.363) and moderate to good reliability in people aged ≥65 years (0.453-0.780). To conclude, participants with better SC performance are able to largely overshoot the minimal power required to ascend the stairs in a certain duration. This makes the sensor more sensitive to identify early age-related differences compared to the formula.

Effect of High-Intensity Interval Training and Moderate-Intensity Continuous Training in People With Poststroke Gait Dysfunction: ARandomized Clinical Trial.

The exercise strategy that yields the greatest improvement in both cardiorespiratory fitness () and walking capacity poststroke has not been determined. This study aimed to determine whether conventional moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) have different effects on and 6-minute walk distance (6MWD). In this 24-week superiority trial, people with poststroke gait dysfunction were randomized to MICT (5 days/week) or HIIT (3 days/week with 2 days/week of MICT). MICT trained to target intensity at the ventilatory anaerobic threshold. HIIT trained at the maximal tolerable treadmill speed/grade using a novel program of 2 work-to-recovery protocols: 30:60 and 120:180 seconds. V̇O2 and heart rate was measured during performance of the exercise that was prescribed at 8 and 24 weeks for treatment fidelity. Main outcomes were change in and 6MWD. Assessors were blinded to the treatment group for but not 6MWD. Secondary outcomes were change in ventilatory anaerobic threshold, cognition, gait-economy, 10-meter gait-velocity, balance, stair-climb performance, strength, and quality-of-life. Among 47 participants randomized to either MICT (n=23) or HIIT (n=24) (mean age, 62±11 years; 81% men), 96% completed training. In intention-to-treat analysis, change in for MICT versus HIIT was 2.4±2.7 versus 5.7±3.1 mL·kg-1·min-1 (mean difference, 3.2 [95% CI, 1.5-4.8]; P<0.001), and change in 6MWD was 70.9±44.3 versus 83.4±53.6 m (mean difference, 12.5 [95% CI, -17 to 42]; P=0.401). HIIT had greater improvement in ventilatory anaerobic threshold (mean difference, 2.07 mL·kg-1·min-1 [95% CI, 0.59-3.6]; P=0.008). No other between-group differences were observed. During V̇O2 monitoring at 8 and 24 weeks, MICT reached 84±14% to 87±18% of while HIIT reached 101±22% to 112±14% of (during peak bouts). HIIT resulted in more than a 2-fold greater and clinically important change in than MICT. Training to target (ventilatory anaerobic threshold) during MICT resulted in ~3 times the minimal clinically important difference in 6MWD, which was similar to HIIT. These findings show proof of concept that HIIT yields greater improvements in cardiorespiratory fitness than conventional MICT in appropriately screened individuals. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03006731.

The Time Course of Health, Fitness, and Occupational Performance Changes in Recruits across a Fire Academy.

The purpose of this study was to examine the time course of health, fitness, and occupational performance changes in firefighter recruits across a fire academy. Nineteen recruits (24.9 ± 4.3 yr; 26.7 ± 3.1 kg·m -2 ) had their body composition, balance, vertical jump (VJ) performance, cardiorespiratory fitness (CRF), upper and lower body strength, hamstrings-to-quadriceps (H/Q) ratio, lower back endurance, and weighted stair climb (SC) performance assessed at the beginning (week 1 [W1]), midpoint (week 15 [W15]), and end (week 30 [W30]) of a fire academy. The fire academy improved body composition, balance, CRF, leg extension strength, and SC performance from W1 to W15 ( P ≤ 0.042) which then plateaued at W30 ( P ≥ 0.314). Leg flexion strength and the H/Q ratio decreased from W1 to W15 ( P ≤ 0.035) and plateaued at W30 ( P ≥ 0.947). Upper body strength was similar at W1 and W15 ( P ≥ 0.999), but decreased at W30 ( P ≤ 0.033). However, no significant changes occurred across the academy for VJ performance or lower back endurance ( P ≥ 0.090). These findings highlight the positive effect of the academy on body composition, CRF, balance, SC performance, and leg extension strength. However, the decreases in upper body and leg flexion strength, the H/Q ratio, and lack of changes in VJ performance and low back endurance may highlight key areas of need to maximize injury prevention and performance enhancement efforts in the academy. Further, the varied time course of changes may help fire departments identify opportunities to modify exercise programming across their academies.

Stair-Climbing Robots: A Review on Mechanism, Sensing, and Performance Evaluation

Indoor service robots have been widely introduced in the fields of cleaning, delivery, education, guidance, and healthcare, etc. in indoor environments. The mobility of an indoor service robot is essential to expanding its applications. However, the mobility of existing indoor service robots is highly limited by surrounding indoor environments. For example, a stair is one of the major obstacles that restrict the reachable areas of indoor service robots. Even though many studies have been performed to develop reliable and fast stair-climbing robots based on legged, tracked, wheel-legged and wheel-linkage mechanisms, a market-dominant stair-climbing robot remains unsolved. This review investigates the efforts of engineers devoted to stair-climbing robots. To this end, the locomotion mechanisms of stair climbing robots are classified and their sensing method are summarized. In this review, we also propose useful criteria for evaluating the stair-climbing ability of an indoor service robot. By virtue of these criteria, the stair-climbing performance of existing robots are qualitatively compared. We hope this review helps develop the reliable and fast stair-climbing robots and the reasonable criteria for their performances.

Design exploration and comparative analysis of tail shape of tri-wheel-based stair-climbing robotic platform

Stair climbing is one of the most important capabilities of mobile robots. Therefore, stair-climbing mobile robots have become a field of study and diverse stair-climbing mobile robots have been developed. Although tri-wheel-based stair-climbing robotic platforms were developed to overcome the challenges posed by stair climbing, they have shown limitations such as impact during locomotion and damage owing to friction with the nosing of the stairs. In this study, several tail mechanisms were proposed and designed to solve the limitations of tri-wheel-based stair-climbing robots. A comparative analysis of the tail mechanisms was performed through dynamic simulations based on various performance indices. It was observed that the tail mechanism improved the stability and stair-climbing performance of the tri-wheel-based stair-climbing robots. The experimental verification confirmed the reliability of the comparative analysis results based on the simulation. These findings can be used to design mobile stair-climbing robots.

The Impact Of Leg Asymmetry On Stair Climb Performance In Career Firefighters

Limb-specific regional tissue distribution can be determined using segmental body composition analyses to indicate between limb asymmetries. It is unclear how leg muscle imbalance, as measured by fat free mass, may contribute to performance on job-related tasks. PURPOSE: The purpose of this study was to examine the relationship between leg fat free mass asymmetry (FFMA) and stair climb performance (SCP) in career firefighters. METHODS: Forty-one firefighters [age: 32.3±8.2 years (20-50); stature: 178.3±7.9 cm (159.2-194.6); mass: 92.3±18.7 kg (65.1-133.2); %BF: 24.1±7.9% (9.9-39.4)] volunteered for this investigation. All participants were free of any neuromuscular, cardiovascular, or metabolic diseases, and were instructed to refrain from caffeine and smokeless tobacco for 12 hours, and vigorous lower body exercise for 48 hours. Following an 8 hour fast, %BF and leg FFM was assessed by a daily calibrated dual-energy x-ray absorptiometry. Participants were fitted with a weighted vest (22.73 kg) to simulate the load of their personal protective equipment and self-contained breathing apparatus. Performance was measured as time to completion (s) of stair assent and decent of 26 stairs (20 cm stair height) four times as fast as possible (104 total stairs). Leg FFMA was defined as ±3% difference between leg fat free mass as a cutoff point. A point biserial correlation between FFMA and SCP was performed. In addition, the relationship between FFMA and SCP, while controlling for age and %BF, was assessed. An alpha level was set a priori at 0.05. RESULTS: The point biserial correlation demonstrated that FFMA was significantly associated with SCP (r=0.519, P<0.001). Due to the large range in age and %BF, a follow-up partial correlation analysis controlling for these variables was performed and indicated a similar relationship between FFMA and SCP (r = 0.561, P<0.001). CONCLUSIONS: These findings suggest that the presence of leg FFMA is related to poorer performance on the stair climb assessment with and without accounting for age and %BF. While age is non-modifiable, maintaining good body composition (i.e., %BF and muscle symmetry) as a firefighter may help preserve performance on fire-related tasks. Strategies to improve body composition may impact SCP in firefighters.

Impact Of Resistance Training On Skeletal Muscle Mass And Physical Function In Older Adults

Aging is often accompanied with the onset of sarcopenia, defined by low muscle mass, strength, and physical function. Regular resistance exercise may mitigate this loss; however, data are lacking that compare young and old adults who do and do not perform resistance training for general health on skeletal muscle mass and physical function. PURPOSE: The aim of this study was to identify differences in muscle mass and physical function between young and old adults who did and did not perform resistance training for general health. METHODS: Healthy younger (23.8 ± 0.6 yrs) and older (68.6 ± 1.7 yrs) men and women (n = 67) who either did or did not regularly participate in resistance training were assigned to 1 of 4 groups: young trained (YT: n = 22); young not trained (YNT: n = 15); old trained (OT: n = 11); and old not trained (ONT: n = 19). Dual energy x-ray absorptiometry assessed appendicular skeletal muscle mass (SMI). Participants performed 4 physical function tests: stair climb (SC), 30s sit-to-stand (30sSTS), 6-min walk test (6MWT), and timed-up-and-go (TUG). ANOVAs were used to compare groups for all measures, p ≤ 0.05. Data are reported as mean ± SE. RESULTS: We found differences between groups for SMI, SC, 30sSTS, 6MWT, and TUG (p ≤ 0.05). SMI was higher for YT compared to YNT (p = 0.003) and ONT (p > 0.003; YT: 8.60 ± 0.37 kg/m2, YNT: 6.88 ± 0.17 kg/m2, OT: 7.69 ± 0.42 kg/m2, ONT: 7.04 ± 0.29 kg/m2). SC performance was faster for YT (p < 0.0001), YNT (p < 0.0001) and OT (p = 0.03) compared to ONT (YT: 2.37 ± 0.05 s, YNT: 2.52 ± 0.08 s, OT: 2.81 ± 0.12 s, ONT: 3.33 ± 0.17 s). For 30sSTS, OT completed more reps than ONT (p < 0.0001) and YT completed more reps than YNT (p = 0.001) and ONT (p < 0.0001; YT: 22.8 ± 0.5 reps, YNT: 18.9 ± 0.7 reps, OT: 21.6 ± 1.3 reps, ONT: 16.7 ± 0.6 reps). For 6MWT, OT walked farther than ONT (p = 0.017) and YT walked farther than ONT (p = 0.001; YT: 837.0 ± 16.7 yds, YNT: 785.5 ± 15.1 yds, OT: 829.2 ± 31.9 yds, ONT: 733.6 ± 20.4 yds). For TUG, OT was faster than ONT (p = 0.006; YT: 5.81 ± 0.17 s, YNT: 5.88 ± 0.26 s, OT: 5.21 ± 0.23 s, ONT: 6.38 ± 0.23 s). SMI, SC, 30sSTS, 6MWT and TUG were not different between OT and YT or YNT (p > 0.05). All other comparisons were not significantly different (p > 0.05). CONCLUSION: These data suggest that older adults who engage in regular resistance training may maintain muscle mass and physical function similar to that of younger adults.

Deriving stair-climbing performance outcome measures using the smartphone barometer: Results of an algorithm development study

As we seek to gain richer insights to understand intervention effects, and increasingly decentralise aspects of clinical trials to simplify participation, there is a growing interest in leveraging wearables and sensors to generate novel and informative clinical outcome measures for at-home assessment. The sensors embedded within smartphone technology provide one approach to capture of this data, and may be particularly useful when patients are already using mobile devices for at-home capture of other clinical trials data, such as patient-reported outcomes.We describe the results of an initial algorithm development study to determine whether the atmospheric pressure data provided by an onboard smartphone sensor is sufficiently informative to enable detection of a small height gain, such as that achieved during a short stair climb performance test. We were able to sufficiently distinguish height changes of 0.6 m in indoor conditions, representing around 4 stairs on an average staircase. This suggests that the smartphone barometer may indeed be suitable for inclusion within future work developing a stair-climbing performance outcome test instrumented using a mobile application.

Neuromuscular determinants of simulated occupational performance in career firefighters

PurposeAlthough firefighters are required to perform various high-intensity critically essential tasks, the influence of neuromuscular function on firefighter occupational performance is unclear. The primary aim of the current study was to identify the key neuromuscular determinants of stair climb (SC) performance in firefighters. MethodsLeg extension isometric peak torque (PT), peak power (PP), torque steadiness at 10% (Steadiness10%) and 50% (Steadiness50%) of PT, fatigability following 30 repeated isotonic concentric contractions at 40% of PT, percent body fat (%BF), and a weighted and timed SC task were examined in 41 (age: 32.3 ± 8.2 yrs; %BF: 24.1 ± 7.9%) male career firefighters. ResultsFaster SC times (74.7 ± 13.4 s) were associated with greater PT and PP, less fatigability, younger age, and lower %BF (r = −0.530–0.629; P ≤ 0.014), but not Steadiness10% or Steadiness50% (P ≥ 0.193). Stepwise regression analyses indicated that PP and Steadiness50% were the strongest predictors of SC time (R2 = 0.442, P < 0.001). However, when age and %BF were included in the model, these variables became the only significant predictors of SC time (R2 = 0.521, P < 0.001) due to age and %BF being collectively associated with all the neuromuscular variables (excluding Steadiness10%). ConclusionsLower extremity neuromuscular function, specifically PP and steadiness, and %BF are important modifiable predictors of firefighter SC performance, which becomes increasingly important in aging firefighters.

PNS3 Deriving STAIR-Climbing Performance Outcome Measures Using the Smartphone Barometer: Results of a Test of Concept Study

We have developed an Android mobile application that can sample from any on-board smartphone sensor. This is intended to enable objective performance outcome (PerfO) measures to be developed for remote assessments in clinical trials. This study aimed to assess the suitability of the smartphone barometer in detecting and measuring height changes that could have application in instrumenting an at-home stair-climbing PerfO using a smartphone. The stability of atmospheric pressure (AP) measurements was assessed in 3 conditions: indoor with windows closed (INWC), indoor with windows open (INWO) and outdoors (OUT) by measuring AP for 60 s (3 repetitions). The ability to detect height transitions was assessed by holding the smartphone at a constant height for 20 s, moving vertically for 0.6 m, and retaining the new height for 20 s (8 repetitions per condition). AP data were smoothed using a Savitzky-Golay filter and converted to altitude heights using the barometric formula. Height gain was estimated by algorithmic detection of the height transition event and estimating the mean AP before and after transition. AP measurements were symmetrically distributed. Fluctuations from the mean were greater for INWO and OUT. Height transition was successfully detected in all repetitions for each condition. Mean [SD] estimates of height gain were 0.65 [0.13] m, 0.66 [0.16] m and 0.81 [0.15] m for INWC, INWO and OUT respectively. OUT estimates were significantly different to the true value of 0.6 m (p=0.016). Smartphone barometer data is able to adequately detect height transitions of 0.6 m, especially in indoor conditions. 0.6 m corresponds to an elevation of approximately 3 stairs within a standard staircase, meaning that the barometer may be useful in helping to instrument an at-home stair-climbing PerfO when combined with a timer using a smartphone app.

Neuromuscular Factors Associated With Stair Climb Performance In Firefighters

PURPOSE: The weighted stair climb is a critical and essential occupational task for career firefighters. However, limited data is available investigating the influence of neuromuscular function on stair climb performance (SCP). The purpose of this study was to examine the influence of lower extremity strength, power, fatigability, and steadiness on SCP. METHODS: Forty-one firefighters (32.34±8.20 yrs) completed one laboratory visit where they completed leg extension strength testing of the dominant leg on an isokinetic dynamometer to determine peak torque (PT). Participants then traced a line at 10% (Stead10) and 50% (Stead50) of PT for 30 seconds to determine steadiness (coefficient variation of torque). Fatigability was determined from the reduction in PT following 30 consecutive isotonic contractions (80° of range of motion) at 40% of their PT. Peak power (PP) was determined from the highest value during the first five isotonic contractions. PT and PP were normalized to body mass (kg) prior to analysis (PT/kg and PP/kg). Following a 20-minute rest, participants then completed a weighted (22.73 kg vest) stair climb by ascending and descending 26 steps, four times. Pearson’s product-moment correlation coefficients were used to examine the associations between each neuromuscular variable and SCP. A stepwise multiple regression analysis was then completed to determine the relative contributions of all neuromuscular variables on SCP. An a priori alpha level of ≤ 0.05 was used to determine statistical significance. RESULTS: Faster SCP was associated with greater PP/kg (r = -0.530; P=0.001), PT/kg (r = -0.421; P=0.007), and lower fatigability (r = 0.389; P=0.014). The stepwise multiple regression analyses determined that PP/kg and Stead50 were the most significant predictors of SCP (R2 = 0.442; P=0.013). CONCLUSIONS: Our findings suggest that lower extremity power output and motor control are the strongest neuromuscular predictors of SCP. These findings are impactful considering these variables can be improved with exercise.

Factors Influencing Longitudinal Stair Climb Performance from Midlife to Early Late Life: The Study of Women's Health Across the Nation Chicago and Michigan Sites.

To quantify the longitudinal change in stair climb performance (a measure indicative of both physical function and muscle power), determine whether physical activity is related to slower decline in performance, and to identify factors that modify the longitudinal change in performance among women from midlife to late life. Longitudinal cohort study with up to 15 study visits. Two sites of the Study of Women's Health Across the Nation. Black (n=411) and white (N=419) women followed from median age 47.0 (44.6-49.6) to 62.0 (55.8-65.3) years. N/A. Performance on a stair climb test (ascend/descend 4 steps, 3 cycles) was timed. Physical activity (PA) was assessed using the Kaiser Physical Activity Survey (KPAS; possible range 0-15 points). Sociodemographic and health factors were assessed via self-report. BMI was calculated with measured height and weight. Mixed-effects regression modeled longitudinal change in stair climb performance. Average baseline stair climb time was 18.12 seconds (95% CI: 17.83-18.41), with 0.98% (95% CI: 0.84%-1.11%) annual slowing. In fully adjusted models, higher levels of PA were associated with faster stair climb times (2.09% faster per point higher, 95% CI: -2.87%- -1.30%), and black women had 5.22% (95% CI: 2.43%-8.01%) slower performance compared to white women. Smoking, financial strain, diabetes, osteoarthritis, fair/poor health, and stroke were associated with 3.36% (95% CI: 0.07%-6.65%), 7.56% (95% CI: 4.75%-10.37%), 8.40% (95% CI: 2.89%-13.92%), 8.46% (95% CI: 5.12%-11.79%), 9.16% (95% CI: 4.72%-13.60%), and 16.94% (95% CI: 5.37%-28.51%) slower performance, respectively. In separate models, higher BMI (per 1-unit), osteoarthritis, fair/poor health, and diabetes, were each associated with 0.06% (95% CI:0.04%-0.08%), 0.48% (95% CI:0.12%-0.84%), 0.81% (95% CI:0.35%-1.28%), and 0.84% (95% CI:0.22%-1.46%), additional slowing per year over time. Significant declines in function were evident as women transitioned from midlife to early late life. Declines were amplified by indicators of poor health, emphasizing the importance of health in midlife for promoting healthy aging.

Associations Between Stair Climb Performance, Ultrasound Measured Muscle Thickness of the Lower Limbs and Self-Reported Pain and Function in Patients with Knee Osteoarthritis

Abstract Background: Knee osteoarthritis (OA) commonly limits stair climbing. This study aimed to determine if self-reported pain and function and biomechanics during stair climbing were associated with ultrasound

Trajectories of Stair Climbing Performance for Black and White Midlife Women

Trajectories of Stair Climbing Performance for Black and White Midlife Women

Self-efficacy, pain, and quadriceps capacity at baseline predict changes in mobility performance over 2years in women with knee osteoarthritis.

This study examined the extent to which baseline measures of quadriceps strength, quadriceps power, knee pain and self-efficacy for functional tasks, and their interactions, predicted 2-year changes in mobility performance (walking, stair ascent, stair descent) in women with knee osteoarthritis. We hypothesized that lesser strength, power and self-efficacy, and higher pain at baseline would each be independently associated with reduced mobility over 2years, and each of pain and self-efficacy would interact with strength and power in predicting 2-year change in stair-climbing performance. This was a longitudinal, observational study of women with clinical knee osteoarthritis. At baseline and follow-up, mobility was assessed with the Six-Minute Walk Test, and stair ascent and descent tasks. Quadriceps strength and power, knee pain, and self-efficacy for functional tasks were also collected at baseline. Multiple linear regression examined the extent to which 2-year changes in mobility performances were predicted by baseline strength, power, pain, and self-efficacy, after adjusting for covariates. Data were analyzed for 37 women with knee osteoarthritis over 2years. Lower baseline self-efficacy predicted decreased walking (β=1.783; p=0.030) and stair ascent (β=-0.054; p<0.001) performances over 2years. Higher baseline pain intensity/frequency predicted decreased walking performance (β=1.526; p=0.002). Lower quadriceps strength (β=0.051; p=0.015) and power (β=0.022; p=0.022) interacted with lesser self-efficacy to predict worsening stair ascent performance. Strategies to sustain or improve mobility in women with knee osteoarthritis must focus on controlling pain and boosting self-efficacy. In those with worse self-efficacy, developing knee muscle capacity is an important target.

Altered spatiotemporal characteristics of gait in older adults with chronic low back pain

Previous studies in older adults have identified that chronic low back pain (CLBP) is associated with slower gait speed. Given that slower gait speed is a predictor of greater morbidity and mortality among older adults, it is important to understand the underlying spatiotemporal characteristics of gait among older adults with CLBP. The purposes of this study were to determine (1) if there are differences in spatiotemporal parameters of gait between older adults with and without CLBP during self-selected and fast walking and (2) whether any of these gait characteristics are correlated with performance of a challenging walking task, e.g. stair negotiation. Spatiotemporal characteristics of gait were evaluated using a computerized walkway in 54 community-dwelling older adults with CLBP and 54 age- and sex-matched healthy controls. Older adults with CLBP walked slower than their pain-free peers during self-selected and fast walking. After controlling for body mass index and gait speed, step width was significantly greater in the CLBP group during the fast walking condition. Within the CLBP group, step width and double limb support time are significantly correlated with stair ascent/descent times. From a clinical perspective, these gait characteristics, which may be indicative of balance performance, may need to be addressed to improve overall gait speed, as well as stair-climbing performance. Future longitudinal studies confirming our findings are needed, as well as investigations focused on developing interventions to improve gait speed and decrease subsequent risk of mobility decline.

Reference values and factors associated with musculoskeletal symptoms in healthy adolescents and adults

BackgroundInsufficient attention has been given to individuals who report musculoskeletal symptoms yet experience minimal disability. ObjectivesTo examine musculoskeletal symptoms among healthy individuals, and compare demographic, psychological and physical factors between individuals with and without symptoms. DesignCross-sectional observational study. MethodData were from the 1000 Norms Project which recruited 1000 individuals aged 3–101 years. Participants were healthy by self-report and had no major physical disability. Musculoskeletal symptoms (ache/pain/discomfort, including single-site and multi-site symptoms) were assessed in adolescents (11–17y) and adults (18–101y) using the Extended Nordic Musculoskeletal Questionnaire (NMQ-E). To compare individuals with single-site, multi-site and no symptoms, body mass index, grip strength, 6-min walk, 30-s chair stand and timed up-and-down stairs (all participants), and mental health, sleep difficulties, self-efficacy and physical activity (adults), were collected. Results/findings: Socio-demographic characteristics were similar to the Australian population. Twelve-month period prevalence of all symptoms was 69–82%; point prevalence was 23–39%. Adults with single-site symptoms were more likely to be overweight/obese and had lower sit-to-stand and stair-climbing performance (p < 0.05). Adults with multi-site symptoms were more likely to be female and overweight/obese, had lower mental health, greater sleep difficulties and lower grip strength, 6-min walk and sit-to-stand performance (p < 0.05). Differences were only observed among 50–59, 60–69, 70–79 and 80–101 year-olds. ConclusionsNormative reference data for the NMQ-E have been generated. Musculoskeletal symptoms are common among healthy individuals. In older adults, musculoskeletal symptoms are linked with overweight/obesity, lower mental health, sleep difficulties and lower physical performance, emphasising the importance of multi-dimensional assessments in musculoskeletal disorders.

Amount of balance necessary for the independence of transfer and stair-climbing in stroke inpatients

Purpose: The purpose of this study was to clarify the amount of balance necessary for the independence of transfer and stair-climbing in stroke patients.Method: This study included 111 stroke inpatients. Simple and multiple regression analyses were conducted to establish the association between the FIM® instrument scores for transfer or stair-climbing and Berg Balance Scale. Furthermore, receiver operating characteristic curves were used to elucidate the amount of balance necessary for the independence of transfer and stair-climbing.Result: Simple and multiple regression analyses showed that the FIM® instrument scores for transfer and stair-climbing were strongly associated with Berg Balance Scale. On comparison of the independent and supervision-dependent groups, Berg Balance Scale cut-off values for transfer and stair-climbing were 41/40 and 54/53 points, respectively. On comparison of the independent-supervision and dependent groups, the cut-off values for transfer and stair-climbing were 30/29 and 41/40 points, respectively.Conclusions: The calculated cut-off values indicated the amount of balance necessary for the independence of transfer and stair-climbing, with and without supervision, in stroke patients. Berg Balance Scale has a good discriminatory ability and cut-off values are clinically useful to determine the appropriate independence levels of transfer and stair-climbing in hospital wards.Implications for rehabilitationThe Berg Balance Scale’s (BBS) strong association with transfer and stair-climbing independence and performance indicates that establishing cut-off values is vitally important for the established use of the BBS clinically.The cut-off values calculated herein accurately demonstrate the level of balance necessary for transfer and stair-climbing independence, with and without supervision, in stroke patients.These criteria should be employed clinically for determining the level of independence for transfer and stair-climbing as well as for setting balance training goals aimed at improving transfer and stair-climbing.

Influence of Lower Extremity Muscle Size and Quality on Stair-Climb Performance in Career Firefighters.

The purpose of this study was to examine the influence of lower extremity muscular size and quality on stair-climb performance (SCP) in career firefighters. Forty-six male career firefighters (age = 37.0 ± 7.2 years; stature = 180.2 ± 6.9 cm; body mass = 108.0 ± 19.8 kg) volunteered for this study. Panoramic ultrasound images of the vastus lateralis and rectus femoris were obtained to determine cross-sectional area (CSA) and echo intensity (EI) of each muscle. The CSA of each muscle was then summed together and normalized to body mass (CSA/BM [QCSA]). Additionally, EI was averaged across both muscles (QEI). Participants then performed a timed and weighted SCP assessment where they ascended and descended 26 stairs 4 times as quickly as possible while wearing a weighted vest (22.73 kg) to simulate the weight of their self-contained breathing apparatus and turnout gear. Bivariate correlations and stepwise regression analyses were used to examine the relationships among variables and the relative contributions of QCSA and QEI to SCP. Partial correlations were used to examine the relationship between QCSA and SCP and QEI and SCP while controlling for age and body mass index (BMI). The results indicated that QCSA and QEI were significantly related to SCP before (r = -0.492, p = 0.001; r = 0.363, p = 0.013, respectively) and after accounting for age and BMI (r = -0.324, p = 0.032; r = 0.413, p = 0.005, respectively). Both QCSA and QEI contributed significantly to the prediction of SCP (r = 0.560, p < 0.001). These findings indicate that lower extremity muscle size and quality are important contributors to critical firefighting tasks, which have been shown to be improved with resistance training.