Surface electromyography and plantar pressure changes with novel gait training device in participants with chronic ankle instability

BackgroundRehabilitation is ineffective at restoring normal gait in chronic ankle instability patients. Our purpose was to determine if a novel gait-training device could decrease plantar pressure on the lateral column of the foot in chronic ankle instability patients.MethodsTen chronic ankle instability patients completed 30 s trials of baseline and gait-training walking at a self-selected pace while in-shoe plantar pressure and surface electromyography were recorded from their anterior tibialis, peroneus longus, medial gastrocnemius, and gluteus medius. The gait-training device applied a medially-directed force to the lower leg via elastic bands during the entire gait cycle. Plantar pressure measures of the entire foot and 9 specific regions of the foot as well as surface electromyography root mean square areas were compared between the baseline and gait-training conditions using paired t-tests with a priori level of significance of p ≤ 0.05.FindingsThe gait-training device decreased pressure time integrals and peak pressures in the lateral midfoot (p = 0.003 and p = 0.003) and lateral forefoot (p = 0.023 and p = 0.005), and increased pressure time integrals and peak pressures for the total foot (p = 0.030 and p = 0.017) and hallux (p = 0.005 and p = 0.002). The center of pressure was shifted medially during the entire stance phase (p < 0.003 for all comparisons) due to increased peroneus longus activity prior to (p = 0.002) and following initial contact (p = 0.002).InterpretationThe gait-training device decreased pressure on the lateral column of the foot and increased peroneus longus muscle activity. Future research should analyze the efficacy of the gait-training device during gait retraining for chronic ankle instability.     

Lean muscle volume of the thigh has a stronger relationship with muscle power than muscle strength in women with knee osteoarthritis

BackgroundThigh lean muscle and intramuscular fat have been implicated in the impairment of physical function observed in people with knee osteoarthritis. We investigated the relationships of quadriceps and hamstrings intramuscular fat fraction and lean muscle volume with muscle power and strength, controlling for neuromuscular activation, and physical performance in women with knee OA.MethodsWomen (n = 20) 55 years or older with symptomatic, radiographic knee osteoarthritis underwent a 3.0T magnetic resonance imaging scan of the thigh of their most symptomatic knee. Axial fat-separated images were analyzed using software to quantify intramuscular fat and lean muscle volumes of the quadriceps and hamstrings. To quantify strength and power of the knee extensors and flexors, participants performed maximum voluntary isometric contraction and isotonic knee extensions and flexions, respectively. Electromyography of the quadriceps and hamstrings was measured. Participants also completed five physical performance tests.FindingsQuadriceps and hamstrings lean muscle volumes were related to isotonic knee extensor (B = 0.624; p = 0.017) and flexor (B = 1.518; p = 0.032) power, but not knee extensor (B = 0.001; p = 0.615) or flexor (B = 0.001; p = 0.564) isometric strength. Intramuscular fat fractions were not related to isotonic knee extensor or flexor power, nor isometric strength. No relationships were found between intramuscular fat or lean muscle volume and physical performance.InterpretationMuscle power may be more sensitive than strength to lean muscle mass in women with knee osteoarthritis. Thigh lean muscle mass, but neither intramuscular nor intermuscular fat, is related to knee extensor and flexor power in women with knee osteoarthritis.     

Rehabilitation and leucine supplementation as possible contributors to an athlete's muscle strength in the reathletization phase following anterior cruciate ligament surgery

ObjectivesTo determine the interest of a muscle rehabilitation program following anterior cruciate ligament reconstruction (ligamentoplasty) and the influence of leucine supplementation on the muscle strength of athletes undergoing reathletization.Material and methodsThe authors have analyzed prospectively, in double blind, two groups of athletes (22 versus 23) who had randomly received either leucine supplementation or a placebo. Muscle strength was measured at the beginning and the end of the program In terms of thigh perimeter, isokinetic testing results, single-leg test and percentage of body fat. The reathletization program was identical in the two groups for an average of 2.7 weeks.ResultsBy the end of the program, both groups had increased their thigh perimeter at 10 and 15 cm from the patella (respectively 1.2 cm and 1.3 cm, P < 0.0001). Fat mass had decreased by 1.28% (P = 0.017). Values of isokinetic muscle strength for the injured limb improved by 13 to 55% with highly significant differences. The leucine group generally showed more improved muscle parameters than the placebo group, with only one significant positive result with regard to thigh muscle perimeter at 10 cm from the patella (P = 0.009).ConclusionWith or without leucine, the rehabilitation program leads to improved muscle quality. Taking leucine appears to promote muscle recovery of the injured limb with regard to a single parameter (thigh muscle perimeter at 10 cm from the patella), while the other parameters showed no significant improvement. A complementary study associating the recovery phase with other dietary supplements might help to optimize these preliminary results.     

VEGF-A gene promoter polymorphisms and microvascular complications in patients with essential hypertension

ObjectivesWe investigated the possible involvement of vascular endothelial growth factor (VEGF-A) gene promoter polymorphisms in essential hypertension (EH).Design and methods1225 bp of the VEGF-A gene promoter were screened for polymorphisms using PCR amplification and direct DNA sequence analysis in 62 EH and 62 normotensive (HS) individuals. Circulating VEGF-A levels were determined by immunoassay.Results?152G/A (p = 0.009) and ?116G/A (p = 0.016) polymorphisms were correlated to hypertension (p < 0.05). Median platelet VEGF-A load in EH was 2.10 fg/plt. Patients with microvascular complications (MC) had higher platelet VEGF-A load than those without (p = 0.005). Multivariate analyses showed that ?116 A allele was an independent predictor of microalbuminuria (p = 0.014) and increased platelet VEGF-A load (p = 0.009) in EH. Platelet VEGF-A load independently predicted MC (p = 0.049) in addition to ?116G/A polymorphism (p = 0.035).ConclusionsAbnormal regulation of VEGF-A due to polymorphism at position ?116 might represent a genetic factor for increased VEGF-A production and MC in EH.     

Multimodal exercise training in multiple sclerosis: A randomized controlled trial in persons with substantial mobility disability

BackgroundMobility disability is a common, debilitating feature of multiple sclerosis (MS). Exercise training has been identified as an approach to improve MS-related mobility disability. However, exercise randomized controlled trials (RCTs) on mobility in MS have generally not selectively targeted those with the onset of irreversible mobility disability.ObjectivesThe current multi-site RCT compared the efficacy of 6-months of supervised, multimodal exercise training with an active control condition for improving mobility, gait, physical fitness, and cognitive outcomes in persons with substantial MS-related mobility disability.Methods83 participants with substantial MS-related mobility disability underwent initial mobility, gait, fitness, and cognitive processing speed assessments and were randomly assigned to 6-months of supervised multimodal (progressive aerobic, resistance, and balance) exercise training (intervention condition) or stretching-and-toning activities (control condition). Participants completed the same outcome assessments halfway through and immediately following the 6-month study period.ResultsThere were statistically significant improvements in six-minute walk performance (F(2158) = 3.12, p = 0.05, η_p² = 0.04), peak power output (F(2150) = 8.16, p < 0.01, η_p² = 0.10), and Paced Auditory Serial Addition Test performance (F(2162) = 4.67, p = 0.01, η_p² = 0.05), but not gait outcomes, for those who underwent the intervention compared with those who underwent the control condition.ConclusionsThis RCT provides novel, preliminary evidence that multimodal exercise training may improve endurance walking performance and cognitive processing speed, perhaps based on improvements in cardiorespiratory capacity, in persons with MS with substantial mobility disability. This is critical for informing the development of multi-site exercise rehabilitation programs in larger samples of persons with MS-related mobility disability.     

Harmony as a convergence attractor that minimizes the energy expenditure and variability in physiological gait and the loss of harmony in cerebellar ataxia

BackgroundThe harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively.MethodsThe gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases.FindingsThe gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P = 0.011, Cohen's D = 0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D = 0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R²_adj = 0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R = 0.421, P = 0.026).InterpretationHarmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns.     

How multi segmental patterns deviate in spastic diplegia from typical developed

BackgroundThe relationship between gait features and coordination in children with Cerebral Palsy is not sufficiently analyzed yet. Principal Component Analysis can help in understanding motion patterns decomposing movement into its fundamental components (Principal Movements). This study aims at quantitatively characterizing the functional connections between multi-joint gait patterns in Cerebral Palsy.Methods65 children with spastic diplegia aged 10.6 (SD 3.7) years participated in standardized gait analysis trials; 31 typically developing adolescents aged 13.6 (4.4) years were also tested. To determine if posture affects gait patterns, patients were split into Crouch and knee Hyperextension group according to knee flexion angle at standing. 3D coordinates of hips, knees, ankles, metatarsal joints, pelvis and shoulders were submitted to Principal Component Analysis.FindingsFour Principal Movements accounted for 99% of global variance; components 1–3 explained major sagittal patterns, components 4–5 referred to movements on frontal plane and component 6 to additional movement refinements. Dimensionality was higher in patients than in controls (p < 0.01), and the Crouch group significantly differed from controls in the application of components 1 and 4–6 (p < 0.05), while the knee Hyperextension group in components 1–2 and 5 (p < 0.05).InterpretationCompensatory strategies of children with Cerebral Palsy (interactions between main and secondary movement patterns), were objectively determined. Principal Movements can reduce the effort in interpreting gait reports, providing an immediate and quantitative picture of the connections between movement components.     

The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis

BackgroundThe association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis.MethodsSixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n = 18), mild pain (n = 27), or moderate/severe pain (n = 22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified.FindingsThe moderate/severe pain group demonstrated worse global pain (P < 0.01) and physical function scores (P < 0.01) compared to the no pain and the mild pain groups. The moderate/severe pain group also walked with greater knee flexion moments during the midstance phase of gait compared to the no pain group (P = 0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P = 0.009), which was associated with higher weight acceptance peak knee adduction moments (P = 0.003) and worse global pain (P = 0.003) and physical function scores (P = 0.006).InterpretationGreater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait.     

Effect of low-impact aerobic exercise combined with music therapy on patients with fibromyalgia. A pilot study

ObjectiveFibromyalgia is a pathological entity characterized by chronic widespread musculoskeletal pain and the presence of “tender points”. It constitutes a significant health problem because of its prevalence and economic impact. The aim of the present study was to determine the therapeutic benefits of low impact aerobic exercise alone or in combination with music therapy in patients with fibromyalgia.MethodsA single-blind randomized controlled pilot trial was performed. Thirty-five individuals with fibromyalgia were divided into three groups: (G1) therapeutic aerobic exercise with music therapy (n = 13); (G2) therapeutic aerobic exercise at any rhythm (n = 13) and (CG) control (n = 9). The intervention period lasted eight weeks. Depression, quality of life, general discomfort and balance were assessed before and after intervention.ResultsAt post-intervention, group G1 improved in all variables (depression (p = 0.002), quality of life (p = 0.017), general discomfort (p = 0.001), and balance (p = 0.000)), while group G2 improved in general discomfort (p = 0.002). The change observed in balance was statistically different between groups (p = 0.01).ConclusionTherapeutic aerobic exercise is effective in improving depression and general discomfort in individuals with fibromyalgia. However, effectiveness is higher when combined with music therapy, which brings about further improvements in quality of life and balance.     

Patients with osteoarthritic knees have shorter orientation and tangent indicatrices during gait

BackgroundThis study introduces two novel outcomes that could be used to identify people with knee osteoarthritis from healthy controls. These outcomes examine the lengths of paths on a sphere derived from knee angle and knee position during gait.MethodsParticipants with moderate knee osteoarthritis (n = 47) and no knee pathology (n = 51) walked overground. The time-varying orientation matrices and position vectors of the knee (leg relative to the thigh) were measured, then arclength (constant speed) parameterized. The orientation matrix column aligned with the long axis of the leg, and the tangent, normal and binormal vectors (Frenet Frame) along the position vectors were calculated. These unit length vectors all scribe paths (indicatrices) on a unit sphere. The path lengths of these indicatrices, for all or part of a gait cycle, were the novel outcomes. A stepwise discriminant analysis defined a linear function that included those outcomes that best allocated a participant to the osteoarthritis or control group.FindingsGroup differences were best detected with the indicatrix lengths associated with the orientation of the leg’s long axis over a gait cycle (P < 0.001) and the tangent vector over the stance phase (P = 0.014). Both outcomes were smaller in the knee osteoarthritis compared to control group. Walking speed was poorly correlated with all indicatrix lengths (ρ < |0.484|) and a discriminate analysis correctly classified 83.7% of the participants.InterpretationSmaller indicatrix measures distinguished those with knee osteoarthritis from healthy controls. These outcomes introduce a promising new kinematic approach when examining gait data.     

Age explains limited hip extension recovery at one year from total hip arthroplasty

BackgroundTo investigate the dependency of the one-year recovery in gait after total hip arthroplasty on age and preoperative conditions.MethodsLongitudinal retrospective study on 20 elderly patients with unilateral total hip arthroplasty consequent to hip osteoarthritis, assessed by gait analysis before surgery (T0), 2 weeks (T1), 6 (T2) and 12 months (T3) post-surgery. A set of variables assessing primary gait deviations and compensatory mechanisms were extracted from gait analysis data. Their variations throughout the one-year period were analyzed through a repeated measures ANOVA. Their dependency on preoperative conditions (age, hip passive limitations and Thomas Test) at one year after surgery were assessed through a correlation analysis and an ANCOVA.FindingsHip sagittal range significantly increased (P < 0.05) after each measurement session from mean 21 (SD 10) degrees at T0, to 31 (6) at T1, to 34 (6) at T2 until 36 (4) degrees at T3. The peak of hip and ankle power generation significantly increased from T0 to T3, with a progressive reduction of compensatory mechanisms towards normal values.At T3, preoperative hip passive extension and Thomas Test score did not affect hip sagittal range during gait, while age did (P < 0.05, R² = 0.36). Ankle and hip peak powers were also correlated with age (P = 0.033 and P = 0.008, respectively). In our sample, age was the main cause of hip sagittal joint range limitation.InterpretationAt one year from total hip arthroplasty, age affects hip joint limitations and gait recovery more than preoperative passive restrictions due to muscle shortening.     

Plasma proprotein convertase subtilisin–kexin type 9 is predominantly related to intermediate density lipoproteins

ObjectivesProprotein convertase subtilisin–kexin type 9 (PCSK9) is a key regulator of low density lipoprotein (LDL) receptor processing, but the PCSK9 pathway may also be implicated in the metabolism of triglyceride-rich lipoproteins. Here we determined the relationship of plasma PCSK9 with very low density lipoprotein (VLDL) and LDL subfractions.Design and methodsThe relationship of plasma PCSK9 (sandwich enzyme-linked immunosorbent assay) with 3 very low density lipoprotein (VLDL) and 3 low density lipoprotein (LDL) subfractions (nuclear magnetic resonance spectroscopy) was determined in 52 subjects (30 women).ResultsIn age- and sex-adjusted analysis plasma PCSK9 was correlated positively with total cholesterol, non-high density lipoprotein cholesterol and LDL cholesterol (r = 0.516 to 0.547, all p < 0.001), as well as with triglycerides (r = 0.286, p = 0.044). PCSK9 was correlated with the VLDL particle concentration (r = 0.336, p = 0.017) and with the LDL particle concentration (r = 0.362, p = 0.010), but only the relationship with the LDL particle concentration remained significant in multivariable linear regression analysis. In an analysis which included the 3 LDL subfractions, PCSK9 was independently related to intermediate density lipoproteins (IDL) (p < 0.001), but not to other LDL subfractions.ConclusionsThis study suggests that plasma PCSK9 predominantly relates to IDL, a triglyceride-rich LDL subfraction. The PCSK9 pathway may affect plasma triglycerides via effects on the metabolism of triglyceride-rich LDL particles.     

Intramedullary nailing vs. palmar locked plating for unstable dorsally comminuted distal radius fractures: A biomechanical study

BackgroundThe purpose of this study was to compare the stability of a 2.4 mm palmar locking compression plate and a new intramedullary nail-plate-hybrid Targon DR for dorsally comminuted distal radius fractures.MethodsAn extraarticular 10 mm dorsally open wedge osteotomy was created in 8 pairs of fresh frozen human radii to simulate an AO–A3-fracture. The fractures were stabilized using one of the fixation methods. The specimens were loaded axially with 200 N and dorsal-excentrically with 80 N. 2000 cycles of dynamic loading and axial loading-to-failure were performed.FindingsAxial loading revealed that intramedullary osteosynthesis (Targon DR: 369 N/mm) was significantly (p = 0.017) stiffer than plate osteosynthesis (Locking compression plate: 131 N/mm). With 214 N/mm the intramedullary nail also showed higher stability during dorsal excentric loading than the Locking compression plate with 51 N/mm (p = 0.012). After 2000 cycles of axial loading with 80 N the Targon DR-group was significantly stiffer than the Locking compression plate-group under both loading patterns. Neither group showed significant changes in stiffness after 2000 cycles. Under dorsal excentric loading the Targon DR-group was still significantly stiffer with 212 N/mm than the Locking compression plate-group with 45 N/mm (p = 0.012). The load to failure tests demonstrated higher stability of intramedullary nailing (625 N) when compared to plate osteosynthesis (403 N) (p < 0.025).InterpretationThe study shows that intramedullary fixation of a distal AO–A3 radial fracture is biomechanically more stable than volar fixed-angle plating under axial and dorsal-excentric loading in an experimental setup.     

CYP1A1, CYP1A2 and CYBA gene polymorphisms associated with oxidative stress in COPD

BackgroundThe genetic susceptibility to chronic obstructive pulmonary disease (COPD) depends on detoxification and antioxidant enzymes, which detoxify cigarette smoke reactive components that, otherwise, generate oxidative stress.MethodsIn a case–control study of 346 subjects with and without COPD, we examined the polymorphisms 462Ile/Val, 3801T/C of CYP1A1, ?3860G/A of CYP1A2 and ?930A/G, 242C/T of CYBA individually or in combination and their contribution to oxidative stress markers by measuring malondialdehyde (MDA), catalase (CAT), glutathione (GSH) and glutathione peroxidase (GPx).ResultsCOPD patients had significantly increased MDA concentration (p < 0.001) and decreased CAT activity, GSH concentration, GPx activity (p ≤ 0.01). The patients were over-represented by the alleles 462Val, 3801C of CYP1A1 and ?930G, 242C of CYBA (p < 0.001, p = 0.003, p = 0.030 and p = 0.031, respectively) and consequently the haplotypes of same alleles i.e. 462Val:3801C, 462Val:3801T and ?930G:242C (p = 0.048, p = 0.016 and p = 0.039, respectively). Similarly, CYP1A1 and CYP1A2 haplotypes, 462Val:3860G and 462Val:3801T:3860G were significantly over-represented (p = 0.001 and p = 0.003), respectively in patients. The same alleles-associated genotype-combinations between genes were more prevalent in patients. Of note, the genotypes, 462Ile/Val+Val/Val, 3801TC+CC of CYP1A1 and ?930AG+GG of CYBA associated with increased MDA concentration (p = 0.018, p = 0.045 and p = 0.017, respectively), decreased CAT activity (p < 0.0001, p = 0.080 and p < 0.0001, respectively) and GSH concentration (p < 0.0001, p = 0.0002 and p = 0.011, respectively) in patients.ConclusionThe identified alleles, its haplotypes and the genotype-combination along with increased oxidative stress, signify the importance in susceptibility to COPD.     

Recovery of balance and gait after stroke is deteriorated by confluent white matter hyperintensities: Cohort study

BackgroundWhite matter hyperintensities (WMHs) are well known to affect post-stroke disability, mainly by cognitive impairment. Their impact on post-stroke balance and gait disorders is unclear.ObjectivesWe aimed to test the hypothesis that WMHs would independently deteriorate post-stroke balance and gait recovery.MethodsThis study was performed in 210 individuals of the cohort Determinants of Balance Recovery After Stroke (DOBRAS), consecutively enrolled after a first-ever hemisphere stroke. Clinical data were systematically collected on day 30 ± 3 (D30) post-stroke and at discharge from the rehabilitation ward. WMHs were searched on MRI, graded with the Fazekas scale, and dichotomized as no/mild (absence/sparse) or moderate/severe (confluent). The primary endpoint was the recovery of the single limb stance, assessed with the Postural Assessment Scale for Stroke (PASS). The secondary endpoint was the recovery of independent gait, assessed with the modified Fugl–Meyer Gait Assessment (mFMA). The adjusted hazard ratios (aHRs) of achievements of these endpoints by level of WMHs were estimated by using Cox models, accounting for other relevant clinical and imaging factors.ResultsIndividuals with moderate/severe WMHs (n = 86, 41%) had greater balance and gait disorders and were more often fallers than others (n = 124, 59%). Overall, they had worse and slower recovery of single limb stance and independent gait (P < 0.001). Moderate/severe WMHs was the most detrimental factor for recovery of balance (aHR 0.46, 95% confidence interval [CI] 0.32–0.68, P < 0.001) and gait (0.51, 0.35–0.74, P < 0.001), along with age, stroke severity, lesion volume and disrupted corticospinal tract. With cerebral infarct, endovascular treatments had an independent positive effect, both on the recovery of balance (aHR 1.65, 95% CI 1.13–2.4, P = 0.009) and gait (1.78, 1.24–2.55, P = 0.002).ConclusionsWMHs magnify balance and gait disorders after stroke and worsen their recovery. They should be better accounted for in post-stroke rehabilitation, especially to help establish a prognosis of mobility.ClinicalTrials.gov registrationNCT03203109.     

Motor-cognitive dual-task training improves local dynamic stability of normal walking in older individuals

BackgroundExtreme levels of gait variability and local dynamic stability of walking are associated with risk of falling and reduced executive functions. However, it is not sufficiently investigated how gait variability and local dynamic stability of human walking develop in the course of a motor-cognitive intervention. As dancing implies high demands on (and therewith trains) executive functioning and motor control, it might increase local dynamic stability or reduce gait variability.Methods32 older healthy participants were randomly assigned to either a health-related exercise group (age: mean = 68.33 years, standard deviation = 3.17 years; BMI: mean = 27.46, standard deviation = 2.94; female/male: 10/6) or a dancing group (age: mean = 66.73 years, standard deviation = 3.33 years; BMI: mean = 26.02, standard deviation = 3.55; female/male: 11/5). Based on angular velocity data of trunk kinematics, local dynamic stability and stride-to-stride variability in level overground walking were assessed prior to and after the specific intervention. The data were analysed by a blinded observer using two-way repeated measures ANOVAs. Based on one-way ANOVAs, time and group effects were determined.FindingsRegarding the variability of trunk movements, no interaction effect was observed (F _1,30 = 0.506, P = .482; η2 = 0.017). For local dynamic stability of trunk movements, an interaction effect in favour of the dancing group was observed (F _1,30 = 5,436; P = .026; η2 = 0.146).InterpretationOur data indicate that a dancing programme (which combines cognitive and motor efforts) might increase local dynamic stability in older people.     

Group antenatal intervention to reduce perinatal stress and depressive symptoms related to intergenerational conflicts: A randomized controlled trial

BackgroundIntergenerational conflicts are a major source of stress, which might lead to depression in new mothers. The conflict is heightened when grandparents are involved in childcare.ObjectivesTo examine the effectiveness of an interpersonal psychotherapy oriented group intervention to reduce stress and depressive symptoms in new mothers and enhance happiness and self-efficacy in managing intergenerational conflict in childcare. This study is one of the intervention projects of FAMILY: A Jockey Club Initiative for a Harmonious Society, funded by The Hong Kong Jockey Club Charities Trust.DesignMultisite randomized controlled trial with two arms: an intervention group attended an additional 4-week program and a control group who received usual care only.SettingSix Maternal and Child Health Centres in Hong KongParticipantsFrom September 2009 to January 2010, 156 pregnant women who would have grandparents involved in childcare were recruited at their 14–32 weeks’ gestation.MethodsParticipants were randomized to groups using computer generated random sequences by blinded recruitment staff. Primary outcomes were stress and depressive symptoms immediately after the intervention and 6–8 weeks after delivery. Secondary outcomes were happiness and self-efficacy in managing conflict.ResultsAfter screening 2870 pregnant women, 156 eligible participants were randomized. Intention-to-treat analysis showed that the intervention group (n = 78) had significantly lower perceived stress (p = 0.017; Cohen d = 0.38) and greater happiness (p = 0.004; Cohen d = 0.41) than the control group (n = 78) immediately after the intervention. However, the effects were not sustained at postnatal follow-up. Subgroup analysis showed that participants with depressive symptoms (EPDS > 12) at baseline reported significantly lower stress, greater happiness (p = 0.035 and 0.037, respectively; both Cohen d = 0.61), greater self-efficacy in managing conflict (p = 0.012; Cohen d = 0.76) than the control group after the intervention. Also, after delivery, they had significantly greater self-efficacy in managing conflict (p = 0.025; Cohen d = 0.61) and more able to cooperate with grandparents in childcare (p = 0.046; Cohen d = 0.59) than the control group.ConclusionThe intervention was effective in reducing stress and enhancing happiness among new mothers, particularly those with higher EPDS scores. Postnatal follow-up contacts as booster interventions may be needed to achieve lasting effects of the intervention.     

Twenty-four-hour profiles of urinary excretion of calcium,magnesium, phosphorus,urea, and creatinine in healthy prepubertal boys

ObjectivesAvailable data on 24-h urinary solute excretion in healthy children are sparse. We thus documented the daily and overnight variations of urinary electrolytes (calcium, magnesium, and phosphorus), urea, and creatinine in prepubertal (Tanner stage I) boys.Design and methodsNine voluntary healthy prepubertal boys aged 10.8 ± 0.11 years participated in this study. Concentrations of variables were quantified in daytime samples (collected between 07:00 h ± 30 min and 21:00 h ± 30 min) and nighttime samples (collected between 21:00 h ± 30 min and 07:00 h ± 30 min) in spring, during a period of 24-h every 3 h.ResultsSignificant differences were found between daytime and nighttime excretion of calcium (p < 0.05), magnesium (p < 0.001), phosphorus (p < 0.01), and urea (p < 0.05), with high concentrations during the night. The 24-h solute/creatinine ratio was 0.072 ± 0.008 mg/mg for calcium, 0.069 ± 0.008 mg/mg for magnesium, 0.698 ± 0.070 mg/mg for phosphorus, and 0.017 ± 0.001 g/mg for urea. Statistically significant correlation analyses showed that urea and creatinine were positively associated with body mass index (BMI) (R = 0.790, p = 0.0113 for urea; R = 0.889, p = <0.0013 for creatinine) and weight (R = 0.717, p = 0.0297 for urea; R = 0.978, p = < 0.001 for creatinine). The other urinary variables were independent of BMI and body mass.ConclusionThese data are of interest for the diagnosis of certain renal disease in prepubertal children.     

A multiple regression normalization approach to evaluation of gait in total knee arthroplasty patients

BackgroundGait features characteristic of a cohort may be difficult to evaluate due to differences in subjects' demographic factors and walking speed. The aim of this study was to employ a multiple regression normalization method that accounts for subject age, height, body mass, gender, and self-selected walking speed in the evaluation of gait in unilateral total knee arthroplasty patients.MethodsThree-dimensional gait analysis was performed on 45 total knee arthroplasty patients and 31 aged-matched controls walking at their self-selected speed. Gait data peaks including joint angles, ground reaction forces, net joint moments, and net joint powers were normalized using subject body mass, standard dimensionless equations, and a multiple regression approach that modeled subject age, height, body mass, gender, and self-selected walking speed.FindingsNormalizing gait data using subject body mass, dimensionless equations, and multiple regression approach resulted in a significantly lower knee adduction moment and knee extensor power in total knee arthroplasty patients compared to controls (p < 0.05). In contrast to normalization using body mass and dimensionless equations, multiple regression normalization greatly reduced variance in gait data by minimizing correlations with subject demographic factors and walking speed, resulting in significantly higher peak hip extension angles and peak hip flexion powers in total knee arthroplasty patients (p < 0.05).InterpretationTotal knee arthroplasty patients generate greater hip extension angles and hip flexor power and have a lower knee adduction moment than healthy controls. This gait pattern may be a strategy to reduce muscle and joint loading at the knee.     

Knee loading asymmetries during gait and running in early rehabilitation following anterior cruciate ligament reconstruction: A longitudinal study

BackgroundNormalization of gait is expected 8–12 weeks after anterior cruciate ligament reconstruction and is a criterion for progression to running. Long-term persistence of sagittal knee loading deficits suggests that early goals are not met. Magnitude and progression of deficits in gait during this time and their relationship to deficits in running are not known.Methods12 individuals status-post reconstruction (5 males) underwent 3-dimensional motion analysis of gait after surgery: one (T1) and three (T2) months and at initiation of running (T3); and running T3. Repeated measures ANOVAs (limb × time) assessed differences in knee flexion, extensor moment impulse and negative work in gait; paired t-tests compared limbs during running; and Pearson's correlations determined associations between limb ratios (moment and work) in gait and running.FindingsLess flexion (− 4.4 (0.63) degrees; mean (SE)), 35% smaller extensor moment (− 0.15 (0.006) Nm 1 s/kg) and 47% less work (− 0.03 (0.008) J/kg) were observed in the surgical knee during gait across time. Moment and work were 1.7 (− 0.1 (0.03) Nm 1 s/kg) and 1.6 times greater (− 0.23 (0.047) J/kg) in non-surgical knee during running. Moment and work limb asymmetries correlated across time during gait (r = 0.778–0.929, P < 0.001) and to asymmetries during running.InterpretationLimb asymmetries in knee loading present one month after reconstruction persist 4 months post-reconstruction. Correlations between limb asymmetries during gait across time and to running suggest that early gait behaviors relate to longer-term loading. Greater attention should be placed on early gait training.