Constant force muscle stretching induces greater acute deformations and changes in passive mechanical properties compared to constant length stretching

Stretching is applied to lengthen shortened muscles in pathological conditions such as joint contractures. We investigated (i) the acute effects of different types of stretching, i.e. constant length (CL) and constant force (CF) stretching, on acute deformations and changes in passive mechanical properties of medial gastrocnemius muscle (MG) and (ii) the association of acute muscle–tendon deformations or changes in mechanical properties with the impulse or maximal strain of stretching. Forty-eight hindlimbs from 13 male and 12 female Wistar rats (13 weeks old, respectively 424.6 ± 35.5 and 261.8 ± 15.6 g) were divided into six groups (n = 8 each). The MG was initially stretched to a length at which the force was 75%, 95%, or 115% of the force corresponding to estimated maximal dorsiflexion and held at either CF or CL for 30 min. Before and after the stretching protocol, the MG peak force and peak stiffness were assessed by lengthening the passive muscle to the length corresponding to maximal ankle dorsiflexion. Also, the muscle belly length and tendon length were measured. CF stretching affected peak force, peak stiffness, muscle belly length, and tendon length more than CL stretching (p &lt; 0.01). Impulse was associated only with the decrease in peak force, while maximal strain was associated with the decrease in peak force, peak stiffness, and the increase in muscle belly length. We conclude that CF stretching results in greater acute deformations and changes in mechanical properties than CL stretching, which appears to be dependent predominantly on the differences in imposed maximal strain.</p

PIN71 QUALITY OF LIFE (QOL) AND OTHER ENDPOINTS COMPARISON IN THE TREATMENT OF FACIAL LIPOATROPHY WITH INJECTION OF POLY-L-LACTIC ACID

Context: Longitudinal data on bone mineral density(BMD) in children and adolescents with Prader-Willi Syndrome (PWS) during long-term GH treatment are not available. Objective: This study aimed to determine effects of long-term GH treatment and puberty on BMD of total body (BMDTB), lumbar spine (BMDLS), and bone mineral apparent density of the lumbar spine (BMAD(LS)) in children with PWS. Design and Setting: This was a prospective longitudinal study of a Dutch PWS cohort. Participants: Seventy-seven children with PWS who remained prepubertal during GH treatment for 4 years and 64 children with PWS who received GH treatment for 9 years participated in the study. Intervention: The children received GH treatment, 1 mg/m(2)/day (congruent to 0.035 mg/kg/d). Main Outcome Measures: BMDTB, BMDLS, and BMAD(LS) was measured by using the same dual-energy x-ray absorptiometry machine for all annual measurements. Results: In the prepubertal group, BMDTB standard deviation score (SDS) and BMDLSSDS significantly increased during 4 years of GH treatment whereas BMAD(LS)SDS remained stable. During adolescence, BMDTBSDS and BMAD(LS)SDS decreased significantly, in girls from the age of 11 years and in boys from the ages of 14 and 16 years, respectively, but all BMD parameters remained within the normal range. Higher Tanner stages tended to be associated with lower BMDTBSDS (P = .083) and a significantly lowerBMAD(LS)SDS (P = .016). After 9 years of GH treatment, lean body mass SDS was the most powerful predictor of BMDTBSDS and BMDLSSDS in adolescents with PWS. Conclusions: This long-term GH study demonstrates that BMDTB, BMDLS, and BMAD(LS) remain stable in prepubertal children with PWS but decreases during adolescence, parallel to incomplete pubertal development. Based on our findings, clinicians should start sex hormone therapy from the age of 11 years in girls and 14 years in boys unless there is a normal progression of puberty

Pancreatitis, very early compared with normal start of enteral feeding (PYTHON trial): design and rationale of a randomised controlled multicenter trial

Contains fulltext : 97199.pdf (publisher's version ) (Open Access)BACKGROUND: In predicted severe acute pancreatitis, infections have a negative effect on clinical outcome. A start of enteral nutrition (EN) within 24 hours of onset may reduce the number of infections as compared to the current practice of starting an oral diet and EN if necessary at 3-4 days after admission. METHODS/DESIGN: The PYTHON trial is a randomised controlled, parallel-group, superiority multicenter trial. Patients with predicted severe acute pancreatitis (Imrie-score >/= 3 or APACHE-II score >/= 8 or CRP > 150 mg/L) will be randomised to EN within 24 hours or an oral diet and EN if necessary, after 72 hours after hospital admission.During a 3-year period, 208 patients will be enrolled from 20 hospitals of the Dutch Pancreatitis Study Group. The primary endpoint is a composite of mortality or infections (bacteraemia, infected pancreatic or peripancreatic necrosis, pneumonia) during hospital stay or within 6 months following randomisation. Secondary endpoints include other major morbidity (e.g. new onset organ failure, need for intervention), intolerance of enteral feeding and total costs from a societal perspective. DISCUSSION: The PYTHON trial is designed to show that a very early (< 24 h) start of EN reduces the combined endpoint of mortality or infections as compared to the current practice of an oral diet and EN if necessary at around 72 hours after admission for predicted severe acute pancreatitis. TRIAL REGISTRATION: ISRCTN: ISRCTN18170985

Functional gait rehabilitation in elderly people following a fall-related hip fracture using a treadmill with visual context: design of a randomized controlled trial

Background: Walking requires gait adjustments in order to walk safely in continually changing environments. Gait adaptability is reduced in older adults, and (near) falls, fall-related hip fractures and fear of falling are common in this population. Most falls occur due to inaccurate foot placement relative to environmental hazards, such as obstacles. The C-Mill is an innovative, instrumented treadmill on which visual context (e. g., obstacles) is projected. The C-Mill is well suited to train foot positioning relative to environmental properties while concurrently utilizing the high-intensity practice benefits associated with conventional treadmill training. The present protocol was designed to examine the efficacy of C-Mill gait adaptability treadmill training for improving walking ability and reducing fall incidence and fear of falling relative to conventional treadmill training and usual care. We hypothesize that C-Mill gait adaptability treadmill training and conventional treadmill training result in better walking ability than usual care due to the enhanced training intensity, with superior effects for C-Mill gait adaptability treadmill training on gait adaptability aspects of walking given the concurrent focus on practicing step adjustments. Methods/design: The protocol describes a parallel group, single-blind, superiority randomized controlled trial with pre-tests, post-tests, retention-tests and follow-up. Hundred-twenty-six older adults with a recent fall-related hip fracture will be recruited from inpatient rehabilitation care and allocated to six weeks of C-Mill gait adaptability treadmill training (high-intensity, adaptive stepping), conventional treadmill training (high-intensity, repetitive stepping) or usual care physical therapy using block randomization, with allocation concealment by opaque sequentially numbered envelopes. Only data collectors are blind to group allocation. Study parameters related to walking ability will be assessed as primary outcome pre-training, post-training, after 4 weeks retention and 12 months follow-up. Secondary study parameters are measures related to fall incidence, fear of falling and general health. Discussion: The study will shed light on the relative importance of adaptive versus repetitive stepping and practice intensity for effective intervention programs directed at improving walking ability and reducing fall risk and fear of falling in older adults with a recent fall-related hip fracture, which may help reduce future fall-related health-care costs

Nutritional therapy and infectious diseases: a two-edged sword

The benefits and risks of nutritional therapies in the prevention and management of infectious diseases in the developed world are reviewed. There is strong evidence that early enteral feeding of patients prevents infections in a variety of traumatic and surgical illnesses. There is, however, little support for similar early feeding in medical illnesses. Parenteral nutrition increases the risk of infection when compared to enteral feeding or delayed nutrition. The use of gastric feedings appears to be as safe and effective as small bowel feedings. Dietary supplementation with glutamine appears to lower the risk of post-surgical infections and the ingestion of cranberry products has value in preventing urinary tract infections in women

Stay focused! The effects of internal and external focus of attention on movement automaticity in patients with stroke

© 2015 Kal et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Dual-task performance is often impaired after stroke. This may be resolved by enhancing patients' automaticity of movement. This study sets out to test the constrained action hypothesis, which holds that automaticity of movement is enhanced by triggering an external focus (on movement effects), rather than an internal focus (on movement execution). Thirty-nine individuals with chronic, unilateral stroke performed a one-leg-stepping task with both legs in single- and dual-task conditions. Attentional focus was manipulated with instructions. Motor performance (movement speed), movement automaticity (fluency of movement), and dual-task performance (dual-task costs) were assessed. The effects of focus on movement speed, single- and dual-task movement fluency, and dual-task costs were analysed with generalized estimating equations. Results showed that, overall, singletask performance was unaffected by focus (p =.341). Regarding movement fluency, no main effects of focus were found in single- or dual-task conditions (p's ≥.13). However, focus by leg interactions suggested that an external focus reduced movement fluency of the paretic leg compared to an internal focus (single-task conditions: p =.068; dual-task conditions: p =.084). An external focus also tended to result in inferior dual-task performance (β = -2.38, p =.065). Finally, a near-significant interaction (β = 2.36, p =.055) suggested that dual-task performance was more constrained by patients' attentional capacity in external focus conditions. We conclude that, compared to an internal focus, an external focus did not result in more automated movements in chronic stroke patients. Contrary to expectations, trends were found for enhanced automaticity with an internal focus. These findings might be due to patients' strong preference to use an internal focus in daily life. Future work needs to establish the more permanent effects of learning with different attentional foci on re-automating motor control after stroke

Is implicit motor learning preserved after stroke? A systematic review with meta-analysis

© 2016 Kal et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Many stroke patients experience difficulty with performing dual-tasks. A promising intervention to target this issue is implicit motor learning, as it should enhance patients' automaticity of movement. Yet, although it is often thought that implicit motor learning is preserved poststroke, evidence for this claim has not been systematically analysed yet. Therefore, we systematically reviewed whether implicit motor learning is preserved post-stroke, and whether patients benefit more from implicit than from explicit motor learning. We comprehensively searched conventional (MEDLINE, Cochrane, Embase, PEDro, PsycINFO) and grey literature databases (BIOSIS, Web of Science, OpenGrey, British Library, trial registries) for relevant reports. Two independent reviewers screened reports, extracted data, and performed a risk of bias assessment. Overall, we included 20 out of the 2177 identified reports that allow for a succinct evaluation of implicit motor learning. Of these, only 1 study investigated learning on a relatively complex, whole-body (balance board) task. All 19 other studies concerned variants of the serial-reaction time paradigm, with most of these focusing on learning with the unaffected hand (N = 13) rather than the affected hand or both hands (both: N = 4). Four of the 20 studies compared explicit and implicit motor learning post-stroke. Meta-analyses suggest that patients with stroke can learn implicitly with their unaffected side (mean difference (MD) = 69 ms, 95% CI[45.1, 92.9], p < .00001), but not with their affected side (standardized MD = -.11, 95% CI[-.45, .25], p = .56). Finally, implicit motor learning seemed equally effective as explicit motor learning post-stroke (SMD = -.54, 95% CI[-1.37, .29], p = .20). However, overall, the high risk of bias, small samples, and limited clinical relevance of most studies make it impossible to draw reliable conclusions regarding the effect of implicit motor learning strategies post-stroke. High quality studies with larger samples are warranted to test implicit motor learning in clinically relevant contexts