Muscle fiber conduction velocity is more affected after eccentric than concentric exercise

It has been shown that mean muscle fiber conduction velocity (CV) can be acutely impaired after eccentric exercise. However, it is not known whether this applies to other exercise modes. Therefore, the purpose of this experiment was to compare the effects of eccentric and concentric exercises on CV, and amplitude and frequency content of surface electromyography (sEMG) signals up to 24 h post-exercise. Multichannel sEMG signals were recorded from biceps brachii muscle of the exercised arm during isometric maximal voluntary contraction (MVC) and electrically evoked contractions induced by motor-point stimulation before, immediately after and 2 h after maximal eccentric (ECC group, N = 12) and concentric (CON group, N = 12) elbow flexor exercises. Isometric MVC decreased in CON by 21.7 ± 12.0% (± SD, p < 0.01) and by 30.0 ± 17.7% (p < 0.001) in ECC immediately post-exercise when compared to baseline. At 2 h post-exercise, ECC showed a reduction in isometric MVC by 24.7 ± 13.7% (p < 0.01) when compared to baseline, while no significant reduction (by 8.0 ± 17.0%, ns) was observed in CON. Similarly, reduction in CV was observed only in ECC both during the isometric MVC (from baseline of 4.16 ± 0.3 to 3.43 ± 0.4 m/s, p < 0.001) and the electrically evoked contractions (from baseline of 4.33 ± 0.4 to 3.82 ± 0.3 m/s, p < 0.001). In conclusion, eccentric exercise can induce a greater and more prolonged reduction in muscle force production capability and CV than concentric exercis

A test of the effort equalization hypothesis in children with cerebral palsy who have an asymmetric gait

Healthy people can walk nearly effortlessly thanks to their instinctively adaptive gait patterns that tend to minimize metabolic energy consumption. However, the economy of gait is severely impaired in many neurological disorders such as stroke or cerebral palsy (CP). Moreover, self-selected asymmetry of impaired gait does not seem to unequivocally coincide with the minimal energy cost, suggesting the presence of other adaptive origins. Here, we used hemiparetic CP gait as a model to test the hypothesis that pathological asymmetric gait patterns are chosen to equalize the relative muscle efforts between the affected and unaffected limbs. We determined the relative muscle efforts for the ankle and knee extensors by relating extensor joint moments during gait to maximum moments obtained from all-out hopping reference test. During asymmetric CP gait, the unaffected limb generated greater ankle (1.36 +/- 0.15 vs 1.17 +/- 0.16 Nm/kg, p = 0.002) and knee (0.74 +/- 0.33 vs 0.44 +/- 0.19 Nm/kg, p = 0.007) extensor moments compared with the affected limb. Similarly, the maximum moment generation capacity was greater in the unaffected limb versus the affected limb (ankle extensors: 1.81 +/- 0.39 Nm/kg vs 1.51 +/- 0.34 Nm/kg, p = 0.033; knee extensors: 1.83 +/- 0.37 Nm/kg vs 1.34 +/- 0.38 Nm/kg, p = 0.021) in our force reference test. As a consequence, no differences were found in the relative efforts between unaffected and affected limb ankle extensors (77 +/- 12% vs 80 +/- 16%, p = 0.69) and knee extensors (41 +/- 17% vs 38 +/- 23%, p = 0.54). In conclusion, asymmetric CP gait resulted in similar relative muscle efforts between affected and unaffected limbs. The tendency for effort equalization may thus be an important driver of self-selected gait asymmetry patterns, and consequently advantageous for preventing fatigue of the weaker affected side musculature.Peer reviewe

Effect of childhood developmental coordination disorder on adulthood physical activity; Arvo Ylppo longitudinal study

Individuals at risk of Developmental Coordination Disorder (DCD) have low levels of physical activity in childhood due to impaired motor competence; however, physical activity levels in adulthood have not been established. This study sought to determine the impact of DCD risk on physical activity levels in adults using accelerometry measurement. Participants (n = 656) from the Arvo Ylppo Longitudinal Study cohort had their motor competence assessed at the age of five years, and their physical activity quantified via device assessment at the age of 25 years. Between group differences were assessed to differentiate physical activity measures for individuals based on DCD risk status, with general linear modeling performed to control for the effects of sex, body mass index (BMI), and maternal education. Participants at risk of DCD were found to have a lower total number of steps (d = 0.3, p = 0.022) than those not at risk. Statistical modeling indicated that DCD risk status increased time spent in sedentary light activity (beta = 0.1, 95% CI 0.02 to 0.3, p = 0.026) and decreased time spent in vigorous physical activity via interaction with BMI (beta = 0.04, 95% CI 0.001 to 0.1, p = 0.025). Sensitivity analysis found that visuomotor impairment did not significantly impact physical activity but did increase the role of DCD risk status in some models. This 20-year-longitudinal study indicated that DCD risk status continues to negatively impact on levels of physical activity into early adulthood.Peer reviewe

Effect of childhood developmental coordination disorder on adulthood physical activity; Arvo Ylppö longitudinal study

Individuals at risk of Developmental Coordination Disorder (DCD) have low levels of physical activity in childhood due to impaired motor competence; however, physical activity levels in adulthood have not been established. This study sought to determine the impact of DCD risk on physical activity levels in adults using accelerometry measurement. Participants (n = 656) from the Arvo Ylppö Longitudinal Study cohort had their motor competence assessed at the age of five years, and their physical activity quantified via device assessment at the age of 25 years. Between group differences were assessed to differentiate physical activity measures for individuals based on DCD risk status, with general linear modeling performed to control for the effects of sex, body mass index (BMI), and maternal education. Participants at risk of DCD were found to have a lower total number of steps (d = 0.3, p = 0.022) than those not at risk. Statistical modeling indicated that DCD risk status increased time spent in sedentary light activity (β = 0.1, 95% CI 0.02 to 0.3, p = 0.026) and decreased time spent in vigorous physical activity via interaction with BMI (β = 0.04, 95% CI 0.001 to 0.1, p = 0.025). Sensitivity analysis found that visuomotor impairment did not significantly impact physical activity but did increase the role of DCD risk status in some models. This 20-year-longitudinal study indicated that DCD risk status continues to negatively impact on levels of physical activity into early adulthood

Cranioplasty After Severe Traumatic Brain Injury: Effects of Trauma and Patient Recovery on Cranioplasty Outcome

Background: In patients with severe traumatic brain injury (sTBI) treated with decompressive craniectomy (DC), factors affecting the success of later cranioplasty are poorly known.Objective: We sought to investigate if injury- and treatment-related factors, and state of recovery could predict the risk of major complications in cranioplasty requiring implant removal, and how these complications affect the outcome.Methods: A retrospective cohort of 40 patients with DC following sTBI and subsequent cranioplasty was studied. Non-injury-related factors were compared with a reference population of 115 patients with DC due to other conditions.Results: Outcome assessed 1 day before cranioplasty did not predict major complications leading to implant removal. Successful cranioplasty was associated with better outcome, whereas a major complication attenuates patient recovery: in patients with favorable outcome assessed 1 year after cranioplasty, major complication rate was 7%, while in patients with unfavorable outcome the rate was 42% (p = 0.003). Of patients with traumatic subarachnoid hemorrhage (tSAH) on admission imaging 30% developed a major complication, while none of patients without tSAH had a major complication (p = 0.014). Other imaging findings, age, admission Glasgow Coma Scale, extracranial injuries, length of stay at intensive care unit, cranioplasty materials, and timing of cranioplasty were not associated with major complications.Conclusion: A successful cranioplasty after sTBI and DC predicts favorable outcome 1 year after cranioplasty, while stage of recovery before cranioplasty does not predict cranioplasty success or failure. tSAH on admission imaging is a major risk factor for a major complication leading to implant removal

Predictors of primary autograft cranioplasty survival and resorption after craniectomy

OBJECTIVECraniectomy is a common neurosurgical procedure that reduces intracranial pressure, but survival necessitates cranioplasty at a later stage, after recovery from the primary insult. Complications such as infection and resorption of the autologous bone flap are common. The risk factors for complications and subsequent bone flap removal are unclear. The aim of this multicenter, retrospective study was to evaluate the factors affecting the outcome of primary autologous cranioplasty, with special emphasis on bone flap resorption.METHODSThe authors identified all patients who underwent primary autologous cranioplasty at 3 tertiary-level university hospitals between 2002 and 2015. Patients underwent follow-up until bone flap removal, death, or December 31, 2015.RESULTSThe cohort comprised 207 patients with a mean follow-up period of 3.7 years (SD 2.7 years). The overall complication rate was 39.6% (82/207), the bone flap removal rate was 19.3% (40/207), and 11 patients (5.3%) died during the follow-up period. Smoking (OR 3.23, 95% CI 1.50–6.95; p = 0.003) and age younger than 45 years (OR 2.29, 95% CI 1.07–4.89; p = 0.032) were found to independently predict subsequent autograft removal, while age younger than 30 years was found to independently predict clinically relevant bone flap resorption (OR 4.59, 95% CI 1.15–18.34; p = 0.03). The interval between craniectomy and cranioplasty was not found to predict either bone flap removal or resorption.CONCLUSIONSIn this large, multicenter cohort of patients with autologous cranioplasty, smoking and younger age predicted complications leading to bone flap removal. Very young age predicted bone flap resorption. The authors recommend that physicians extensively inform their patients of the pronounced risks of smoking before cranioplasty.</div

Circulating alpha1-antitrypsin in the general population: Determinants and association with lung function

BACKGROUND: Severe alpha1-antitrypsin (AAT) deficiency associated with low AAT blood concentrations is an established genetic COPD risk factor. Less is known about the respiratory health impact of variation in AAT serum concentrations in the general population. We cross-sectionally investigated correlates of circulating AAT concentrations and its association with FEV1. METHODS: In 5187 adults (2669 females) with high-sensitive c-reactive protein (CRP) levels < or = 10 mg/l from the population-based Swiss SAPALDIA cohort, blood was collected at the time of follow-up examination for measuring serum AAT and CRP. RESULTS: Female gender, hormone intake, systolic blood pressure, age in men and in postmenopausal women, as well as active and passive smoking were positively, whereas alcohol intake and BMI inversely correlated with serum AAT levels, independent of CRP adjustment. We observed an inverse association of AAT with FEV1 in the total study population (p < 0.001), that disappeared after adjustment for CRP (p = 0.28). In addition, the AAT and FEV1 association was modified by gender, menopausal status in women, and smoking. CONCLUSION: The results of this population-based study reflect a complex interrelationship between tobacco exposure, gender related factors, circulating AAT, systemic inflammatory status and lung function

Plasma levels of alpha1-antichymotrypsin and secretory leukocyte proteinase inhibitor in healthy and chronic obstructive pulmonary disease (COPD) subjects with and without severe α1-antitrypsin deficiency

BACKGROUND: Individuals with severe Z α1-antitrypsin (AAT) deficiency have a considerably increased risk of developing chronic obstructive lung disease (COPD). It has been hypothesized that compensatory increases in levels of other protease inhibitors mitigate the effects of this AAT deficiency. We analysed plasma levels of AAT, α1-antichymotrypsin (ACT) and secretory leukocyte protease inhibitor (SLPI) in healthy (asymptomatic) and COPD subjects with and without AAT deficiency. METHODS: Studied groups included: 71 asymptomatic AAT-deficient subjects (ZZ, n = 48 and SZ, n = 23, age 31 ± 0.5) identified during Swedish neonatal screening for AAT deficiency between 1972 and 1974; age-matched controls (MM, n = 57, age 30.7 ± 0.6); older asymptomatic ZZ (n = 10); healthy MM (n = 20, age 53 ± 9.6); and COPD patients (ZZ, n = 10, age 47.4 ± 11 and MM, n = 10, age 59.4 ± 6.7). Plasma levels of SLPI, AAT and ACT were analysed using ELISA and immunoelectrophoresis. RESULTS: No significant difference was found in plasma ACT and SLPI levels between the healthy MM and the ZZ or SZ subjects in the studied groups. Independent of the genetic variant, subjects with COPD (n = 19) had elevated plasma levels of SLPI and ACT relative to controls (n = 153) (49.5 ± 7.2 vs 40.7 ± 9.1 ng/ml, p < 0.001 and 0.52 ± 0.19 vs 0.40 ± 0.1 mg/ml, p < 0.05, respectively). CONCLUSION: Our findings show that plasma levels of ACT and SLPI are not elevated in subjects with genetic AAT deficiency compared MM controls and do not appear to compensate for the deficiency of plasma AAT

Increasing capacity for the treatment of common musculoskeletal problems: A non-inferiority RCT and economic analysis of corticosteroid injection for shoulder pain comparing a physiotherapist and orthopaedic surgeon

Background Role substitution is a strategy employed to assist health services manage the growing demand for musculoskeletal care. Corticosteroid injection is a common treatment in this population but the efficacy of its prescription and delivery by physiotherapists has not been established against orthopaedic standards. This paper investigates whether corticosteroid injection given by a physiotherapist for shoulder pain is as clinically and cost effective as that from an orthopaedic surgeon. Methods A double blind non-inferiority randomized controlled trial was conducted in an Australian public hospital orthopaedic outpatient service, from January 2013 to June 2014. Adults with a General Practitioner referral to Orthopaedics for shoulder pain received subacromial corticosteroid and local anaesthetic injection prescribed and delivered independently by a physiotherapist or a consultant orthopaedic surgeon. The main outcome measure was total Shoulder Pain and Disability Index (SPADI) score at baseline, six and 12 weeks, applying a non-inferiority margin of 15 points. Secondary outcomes tested for superiority included pain, shoulder movement, perceived improvement, adverse events, satisfaction, quality of life and costs. Results 278 participants were independently assessed by the physiotherapist and the orthopaedic surgeon, with 64 randomised (physiotherapist 33, orthopaedic surgeon 31). There were no significant differences in baseline characteristics between groups. Non-inferiority of injection by the physiotherapist was declared from total SPADI scores at 6 and 12 weeks (upper limit of the 95% one-sided confidence interval 13.34 and 7.17 at 6 and 12 weeks, respectively). There were no statistically significant differences between groups on any outcome measures at 6 or 12 weeks. From the perspective of the health funder, the physiotherapist was less expensive. Conclusions Corticosteroid injection for shoulder pain, provided by a suitably qualified physiotherapist is at least as clinically effective, and less expensive, compared with similar care delivered by an orthopaedic surgeon. Policy makers and service providers should consider implementing this model of care