Acute changes in kinematic and muscle activity patterns in habitually shod rearfoot strikers while running barefoot

The aim of this study was to observe changes in the kinematics and muscle activities when barefoot running was initially adopted by six habitually shod, recreational rearfoot striking runners. Participants ran on a treadmill shod for 5 min, completed 3 × 10-min intervals of barefoot running and then completed a final minute of shod running at a self-selected pace. Dependent variables (speed, joint angles at foot-contact, joint range of motion (ROM), mean and peak electromyography (EMG) activity) were compared across conditions using repeated measures ANOVAs. Anterior pelvic tilt and hip flexion significantly decreased during barefoot conditions at foot contact. The ROM for the trunk, pelvis, knee and ankle angles decreased during the barefoot conditions. Mean EMG activity was reduced for biceps femoris, gastrocnemius lateralis and tibialis anterior during barefoot running. The peak activity across the running cycle decreased in biceps femoris, vastus medialis, gastrocnemius medialis and tibialis anterior during barefoot running. During barefoot running, tibialis anterior activity significantly decreased during the pre-activation and initial contact phases; gastrocnemius lateralis and medialis activity significantly decreased during the push-off phase. Barefoot running caused immediate biomechanical and neuromuscular adaptations at the hip and pelvis, which persisted when the runners donned their shoes, indicating that some learning had occurred during an initial short bout of barefoot running

Dynamic muscle quality of the plantar flexors is impaired in claudicant patients with peripheral arterial disease and associated with poorer walking endurance

Objective Peripheral arterial disease and intermittent claudication (PAD-IC) negatively affects physical activity and function. There is evidence for plantarflexor muscle dysfunction and weakness; however, the extent to which this dysfunction can be attributed to reduced muscle size or quality, or both, is not yet known. This study investigated whether in vivo plantarflexor muscle quality during static and dynamic contractions is altered by PAD-IC and whether such changes are associated with impaired walking endurance according to initial and absolute claudication distances. Methods The study recruited 22 participants, consisting of 10 healthy controls and 12 claudicant patients with occlusion of the superficial femoral artery (seven unilateral and five bilateral). Muscle quality of the combined gastrocnemius muscles during static contractions was calculated by normalizing the estimated maximal potential muscle force to the physiological cross-sectional area of the lateral and medial gastrocnemius. Muscle quality during dynamic contractions of the combined plantarflexor muscles was calculated as the ratio of peak voluntary concentric plantarflexor power and the summed volume of lateral and medial gastrocnemius. Results Dynamic muscle quality was 24% lower in the claudicating-limb and asymptomatic-limb groups compared with controls (P = .017 and P = .023). The differences were most apparent at the highest contraction velocity (180°/s). Dynamic muscle quality was associated with reduced walking endurance (R = 0.689, P = .006 and R = 0.550, P = .042 for initial and absolute claudication distance, respectively). The claudicating-limb group demonstrated a trend toward reduced static muscle quality compared with controls (22%, P = .084). The relative contribution of the soleus muscle to plantarflexion maximum voluntary contraction was significantly higher in the claudicating-limb and asymptomatic-limb groups than in controls (P = .012 and P = .018). Conclusions The muscle strength of the plantarflexors in those with PAD-IC appears to be impaired at high contraction velocities. This may be explained by some reduction in gastrocnemii muscle quality and a greater reliance on the prominently type I-fibered soleus muscle. The reduced dynamic capability of the plantarflexor muscles was associated with disease severity and walking ability; therefore, efforts to improve plantarflexor power through dynamic exercise intervention are vital to maintain functional performance

Biomechanical demands of the 2-step transitional gait cycles linking level gait and stair descent gait in older women

Stair descent is an inherently complex form of locomotion posing a high falls risk for older adults, specifically when negotiating the transitional gait cycles linking level gait and descent. The aim of this study was to enhance our understanding of the biomechanical demands by comparing the demands of these transitions. Lower limb kinematics and kinetics of the 2-step transitions linking level and descent gait at the top (level-to-descent) and the bottom (descent-to-level) of the staircase were quantified in 36 older women with no falls history. Despite undergoing the same vertical displacement (2-steps), the following significant (p<.05) differences were observed during the top transition compared to the bottom transition: reduced step velocity; reduced hip extension and increased ankle dorsiflexion (late stance/pre-swing); reduced ground reaction forces, larger knee extensor moments and powers (absorption; late stance); reduced ankle plantarflexor moments (early and late stance) and increased ankle powers (mid-stance). Top transition biomechanics were similar to those reported previously for continuous descent. Kinetic differences at the knee and ankle signify the contrasting and prominent functions of controlled lowering during the top transition and forward continuance during the bottom transition. The varying musculoskeletal demands encountered during each functional sub-task should be addressed in falls prevention programmes with elderly populations where the greatest clinical impact may be achieved. Knee extensor eccentric power through flexion exercises would facilitate a smooth transition at the top and improving ankle plantarflexion strength during single and double limb stance activities would ease the transition into level gait following continuous descent

Relationships between walking speed, T-score and age with gait parameters in older post-menopausal women with low bone mineral density

Background: The gait patterns of women with low bone mineral density (BMD) or osteoporosis have not been thoroughly explored, and when examined, often studied in relation to falls and kyphosis. Research question: The aim of this study was to investigate the relationships between gait parameters and comfortable, self-selected walking speed and BMD in older post-menopausal women with a broad range of T-scores (healthy to osteoporotic). Methods: 3D kinematic and kinetic data were collected from forty-five women mean (SD) age 67.3 (1.4) years during level walking at their preferred speed. Multiple regression analyses explored the explained variance attributable to speed, femoral neck T-score, and age. Results: The mean (SD) walking speed 1.40 (0.19) m·s−1explained the variance in most temporal-spatial, kinematic and joint powers (R2= 12–68%, P ≤ 0.01). T-score accounted for (R2= 23%, P ≤ 0.001) of the shared explained variance in stride width. It also increased the explanatory power for knee flexion (R2= 7%, P ≤ 0.05) and knee range of motion (R2= 12%, P ≤ 0.01). Power absorption by the knee flexors in terminal swing (K4) was the only power burst resulting in significant slope coefficients for all predictor variables (R2= 52 and 54%) (P ≤ 0.001) and (R2= 68%, P ≤ 0.05). Significance: Speed alone explained most of the variance in the gait parameters, while speed and T-score combined increased the explanatory power of the regression models for some of the knee joint variables. Our findings demonstrated that older post-menopausal women, with a broad range of T-scores, are able to walk at comfortably fast speeds, generating gait patterns similar to those of younger women. The results also suggest that strengthening the hip abductor, knee extensor and flexor muscle groups may benefit the gait patterns of older postmenopausal women with low BMD

A personalised exercise programme for individuals with lower limb amputation reduces falls and improves gait biomechanics: A block randomised controlled trial

Background: Lower limb amputees (LLAs) are at increased risk of falling due to the inherent asymmetry resulting from their limb loss, muscle weakness and other neuro-musculoskeletal limitations. Research question: The aim of this study was to evaluate the effects of a personalised exercise programme on falls prevention and gait parameters in LLAs. Methods: Fifteen LLAs, recruited from their local prosthetic services centre, were block randomised, by age and level of amputation, into two groups: exercise group (transfemoral, n = 5; transtibial, n = 2) and control group (transfemoral, n = 5; transtibial, n = 3). The exercise group completed a 12-week programme, focusing on strength, balance, flexibility and walking endurance, delivered in group sessions at the University, and combined with a personalised home exercise programme. Temporal-spatial, 3D kinematic and kinetic gait parameters were collected at baseline and post-intervention. Falls incidence was also followed up at 12 months. Results: The exercise group experienced significantly fewer falls in the one-year period from baseline, compared with the average annual falls rate, obtained at baseline (P = 0.020; d = 1.54). Gait speed in the exercise group increased by 0.21 m • s −1 , to 0.98 m • s −1 (P < 0.001; d = 0.91), through increased intact limb cadence. In the pre-swing phase, there were significant increases in intact limb peak vertical force, and affected limb peak propulsive (anterior) force for the exercise group. Power absorption and generation significantly increased at both the intact and affected hip joints (H3) and the intact ankle (A1 and A2) for the exercise group, resulting in significant group*time interactions. Significance: This is the first study to document the clinically meaningful benefits of an exercise intervention for falls prevention and gait performance in LLAs. Specialised exercise programmes for community-dwelling LLAs should be implemented as a method to reduce falls and improve walking performance in this population

Agreement and relationship between measures of absolute and relative intensity during walking: a systematic review with meta-regression

IntroductionA metabolic equivalent (MET) is one of the most common methods used to objectively quantify physical activity intensity. Although the MET provides an ‘objective’ measure, it does not account for inter-individual differences in cardiorespiratory fitness. In contrast, ‘relative’ measures of physical activity intensity, such as heart rate reserve (HRR), do account for cardiorespiratory fitness. The purpose of this systematic review with meta-regression was to compare measures of absolute and relative physical activity intensity collected during walking.MethodsA systematic search of four databases (SPORTDiscus, Medline, Academic Search Premier and CINAHL) was completed. Keyword searches were: (i) step* OR walk* OR strid* OR "physical activity"; (ii) absolute OR “absolute intensity” OR mets OR metabolic equivalent OR actigraph* OR acceleromet*; (iii) relative OR “relative intensity” OR "heart rate" OR "heart rate reserve" OR “VO2 reserve” OR VO2* OR “VO2 uptake” OR HRmax* OR metmax. Categories (i) to (iii) were combined using ‘AND;’ with studies related to running excluded. A Bayesian regression was conducted to quantify the relationship between METs and %HRR, with Bayesian logistic regression conducted to examine the classification agreement between methods. A modified Downs and Black scale incorporating 13 questions relative to cross-sectional study design was used to assess quality and risk of bias in all included studies.ResultsA total of 15 papers were included in the systematic review. A comparison of means between absolute (METs) and relative (%HRR, %HRmax, %VO2R, %VO2max, HRindex) values in 8 studies identified agreement in how intensity was classified (light, moderate or vigorous) in 60% of the trials. We received raw data from three authors, incorporating 3 studies and 290 participants. A Bayesian random intercept logistic regression was conducted to examine the agreement between relative and absolute intensity, showing agreement in 43% of all trials. Two studies had identical relative variables (%HRR) totalling 240 participants included in the Bayesian random intercept regression. The best performing model was a log-log regression, which showed that for every 1% increase in METs, %HRR increased by 1.12% (95% CI: 1.10–1.14). Specifically, the model predicts at the lower bound of absolute moderate intensity (3 METs), %HRR was estimated to be 33% (95%CI: 18–57) and at vigorous intensity (6 METs) %HRR was estimated to be 71% (38–100).ConclusionThis study highlights the discrepancies between absolute and relative measures of physical activity intensity during walking with large disagreement observed between methods and large variation in %HRR at a given MET. Consequently, health professionals should be aware of this lack of agreement between absolute and relative measures. Moreover, if we are to move towards a more individualised approach to exercise prescription and monitoring as advocated, relative intensity could be more highly prioritised

The effects of exercise to promote quality of life in individuals with traumatic brain injuries: a systematic review

© 2020 Taylor & Francis Group, LLC. Objective: To systematically review the effects of exercise interventions that may enhance quality of life (QOL) in individuals with traumatic brain injury (TBI). Methods: A systematic search was conducted using five databases up to April 2018. Studies were included if QOL was quantified following an exercise programme for people with a TBI. Methodological quality was assessed using a validated scoring checklist. Two independent reviewers assessed study inclusion and methodological quality. Results: Thirteen studies met the inclusion criteria (seven RCTs, six non-RCTs). The median total scores for the quality assessment tool were 26.1 (RCTs), and 21.3 (non-RCTs), out of 33. Eight out of the 13 studies reported improved QOL following an exercise programme. The duration of the interventions varied from 8-12weeks. The most common programmes involved moderate to vigorous exercise; with a frequency and duration of 3–5 times/week for 30–60minutes. Conclusion: Due to the diversity of the exercise training interventions, heterogeneity of patient characteristics, multitude of QOL instruments and outcome domains assessed, it was not possible to draw any definitive conclusion about the effectiveness of exercise interventions. However, this review identified positive trends to enhance various aspects of QOL measured using a range of assessment tools

Percutaneous transluminal angioplasty results in improved physical function but not balance in patients with intermittent claudication

Objective The aim of this study was to identify whether revascularization by percutaneous transluminal angioplasty (PTA) for patients with intermittent claudication improved measures of functional performance including balance. Methods A prospective observational study was performed at a single tertiary vascular center. Patients with symptomatic intermittent claudication (Rutherford grades 1-3) were recruited to the study. Participants were assessed at baseline (pre-PTA) and then 3, 6, and 12 months post-PTA for markers of (1) lower limb ischemia (treadmill walking distances and ankle-brachial pressure index), (2) physical function (6-minute walk, Timed Up and Go, and chair stand time), (3) balance impairment using computerized dynamic posturography with the Sensory Organization Test, and (4) quality of life (VascuQoL and Short Form Health Survey [SF-36]). Results Forty-three participants underwent PTA. Over 12 months, a significant improvement was demonstrated in initial (P = .04) and maximum treadmill walking distance (P = .019). Physical functional ability improved across all outcome measures (P &lt; .02), and some domains of both generic (P &lt; .03) and disease-specific quality of life (P &lt; .01). No significant improvement in balance was demonstrated by the Sensory Organization Test (P = .24). Conclusions Balance impairment is common in claudicants and does not improve with revascularization. Further research regarding effective treatment of balance impairment is required in this specific group of patients

The effects of robot assisted gait training on temporal-spatial characteristics of people with spinal cord injuries: a systematic review

Context: Robotic assisted gait training (RAGT) technology can be used as a rehabilitation tool or as an assistive device for spinal cord injured (SCI) individuals. Its impact on upright stepping characteristics of SCI individuals using treadmill or overground robotic exoskeleton systems has yet to be established.Objective: To systematically review the literature and identify if overground or treadmill based RAGT use in SCI individuals elicited differences in temporal-spatial characteristics and functional outcome measures.Methods:A systematic search of the literature investigating overground and treadmill RAGT in SCIs was undertaken excluding case-studies and case-series. Studies were included if the primary outcomes were temporal-spatial gait parameters. Study inclusion and methodological quality were assessed and determined independently by two reviewers. Methodological quality was assessed using a validated scoring system for randomized and non-randomized trials.Results: Twelve studies met all inclusion criteria. Participant numbers ranged from 5-130 with injury levels from C2 to T12, American Spinal Injuries Association A-D. Three studies used overground RAGT systems and the remaining nine focused on treadmill based RAGT systems. Primary outcome measures were walking speed and walking distance. The use of treadmill or overground based RAGT did not result in an increase in walking speed beyond that of conventional gait training and no studies reviewed enabled a large enough improvement to facilitate community ambulation.Conclusion: The use of RAGT in SCI individuals has the potential to benefit upright locomotion of SCI individuals. Its use should not replace other therapies but be incorporated into a multi-modality rehabilitation approach