Vertical Jump on a Force Plate for Assessing Muscle Strength and Power in Women With Severe Obesity: Reliability, Validity, and Relations With Body Composition.

ABSTRACT: Bellicha, A, Giroux, C, Ciangura, C, Menoux, D, Thoumie, P, Oppert, J-M, and Portero, P. Vertical jump on a force plate for assessing muscle strength and power in women with severe obesity: reliability, validity, and relations with body composition. J Strength Cond Res 36(1): 75-81, 2022-Muscle strength and power, particularly when assessed during multijoint movements such as vertical jump (VJ), are important predictors of health status and physical function. Vertical jump is mainly used in athletes, also in untrained or older adults, but has not yet been used in subjects with obesity. We aimed to assess the following in this population: (a) the reliability of VJ parameters, (b) their validity compared with isokinetic testing, and (c) their relations with body composition. In 20 women with severe obesity (mean [SD] age: 41.1 [11.6] years; body mass index: 43.9 [4.4] kg·m-2) without severe orthopedic disorders, VJ parameters, knee extension torque, and body composition were assessed using a force plate, an isokinetic dynamometer, and dual-energy x-ray absorptiometry, respectively. Excellent reliability was found for absolute peak power and peak force in VJ (intraclass correlation coefficient [95% confidence interval]: 0.95 [0.88-0.98] and 0.90 [0.77-0.96], respectively), and moderate to good validity of peak power and peak force compared with isokinetic torque (r = 0.79 and r = 0.67, respectively; all p < 0.01). Positive relations were found between peak force and peak power during VJ and lean body mass (r = 0.89 and r = 0.60, respectively; p < 0.01) and a negative relation was found between peak velocity or VJ height and fat mass (r = -0.65 and -0.64, respectively; p < 0.01). These results suggest that VJ on a force plate is a reliable and valid test for assessing muscle strength and power in severely obese subjects. Vertical jump testing is easy to implement, which can facilitate its use in both research and clinical testing in this setting (ClinicalTrials.govID: NCT03325764).

Cutaneous and muscular afferents from the foot and sensory fusion processing: Physiology and pathology in neuropathies.

The foot-sole cutaneous receptors (section 2), their function in stance control (sway minimisation, exploratory role) (2.1), and the modulation of their effects by gait pattern and intended behaviour (2.2) are reviewed. Experimental manipulations (anaesthesia, temperature) (2.3 and 2.4) have shown that information from foot sole has widespread influence on balance. Foot-sole stimulation (2.5) appears to be a promising approach for rehabilitation. Proprioceptive information (3) has a pre-eminent role in balance and gait. Reflex responses to balance perturbations are produced by both leg and foot muscle stretch (3.1) and show complex interactions with skin input at both spinal and supra-spinal levels (3.2), where sensory feedback is modulated by posture, locomotion and vision. Other muscles, notably of neck and trunk, contribute to kinaesthesia and sense of orientation in space (3.3). The effects of age-related decline of afferent input are variable under different foot-contact and visual conditions (3.4). Muscle force diminishes with age and sarcopenia, affecting intrinsic foot muscles relaying relevant feedback (3.5). In neuropathy (4), reduction in cutaneous sensation accompanies the diminished density of viable receptors (4.1). Loss of foot-sole input goes along with large-fibre dysfunction in intrinsic foot muscles. Diabetic patients have an elevated risk of falling, and vision and vestibular compensation strategies may be inadequate (4.2). From Charcot-Marie-Tooth 1A disease (4.3) we have become aware of the role of spindle group II fibres and of the anatomical feet conditions in balance control. Lastly (5) we touch on the effects of nerve stimulation onto cortical and spinal excitability, which may participate in plasticity processes, and on exercise interventions to reduce the impact of neuropathy.

Postrehabilitation Functional Improvements in Patients With Inflammatory Myopathies: The Results of a Randomized Controlled Trial.

OBJECTIVE: To evaluate the medium-term functional effect and the effect on quality of life of a standardized rehabilitation program in patients with inflammatory myopathies (IMs). DESIGN: A multicenter, randomized controlled trial. SETTING: Four university hospitals. PARTICIPANTS: Patients (N=21) with polymyositis. INTERVENTIONS: The intervention group participated in a 4-week standardized, hospital-based rehabilitation program followed by a personalized, self-managed, home-based rehabilitation program. The control group received physiotherapy on an outpatient basis. Study participants were evaluated at inclusion, at the end of the rehabilitation program (1mo), and then at 6 and 12 months. MAIN OUTCOME MEASURES: The primary efficacy criterion was the Health Assessment Questionnaire Disability Index (HAQ-DI), and the secondary criteria were quality of life (according to the Medical Outcomes Study 36-Item Short-Form Health Survey [SF-36] questionnaire), muscle performance (isokinetic strength, Motor Function Measure, and Kendall Manual Muscle Test), gait, pain, fatigue, and biomarkers of tolerance and disease activity. RESULTS: At 12 months, the mean ± SD HAQ-DI was significantly lower in the intervention group than in the control group (.64±.53 vs 1.36±1.02; P=.026). The intervention group also had better scores than the control group for some quality-of-life dimensions (SF-36 General Health: 53.44±8.73 vs 36.57±22.10, respectively; P=.038; SF-36 Role Physical: 63.89±43.50 vs 17.86±37.40, respectively; P=.023) and pain levels (5.0±10.61 vs 33.38±35.68, respectively; P=.04) at 12 months. The program was well tolerated by all the participants. CONCLUSIONS: In patients with IMs, the combination of a 4-week standardized rehabilitation program and a personalized, home-based, self-managed rehabilitation program was well tolerated and had a positive medium-term functional effect.

Good vs Poor Results After Total Hip Arthroplasty: An Analysis Method Using Implant and Anatomic Parameters With the EOS Imaging System.

BACKGROUND: Existing imaging techniques and single-parameter analyses, in nonfunctional positions, fail to detect the differences between patients with good vs poor results after total hip arthroplasty. METHODS: The present study developed an analysis method using the EOS full-body, low-dose, biplanar, weightbearing imaging system to compare good vs poor patients after total hip arthroplasty and to report on our preliminary experiences (17 good, 18 poor). RESULTS: All revision cases were found to have at least 4 high or low implant or anatomic parameters relative to the good group. These included acetabular cup orientation, sagittal pelvic tilt, sacral slope, femoral offset, and neck-shaft angle. Acetabular cup orientation differed significantly between groups. CONCLUSION: With the EOS system, a large cohort can be studied relatively quickly and at low dose, which could lead to patient-specific guidelines.

The relationship of childhood sexual and physical abuse with adulthood disability.

OBJECTIVE: The aim of this study was to examine the association of childhood sexual and physical abuse with disability in adulthood, and to assess how several demographic, physical, behavioral, psychosocial, and psychiatric factors may influence this association. METHODS: This study used nationally representative cross-sectional data from 7403 people aged≥16 years who participated in the 2007 Adult Psychiatric Morbidity Survey. Information on childhood sexual talk, sexual touching, sexual intercourse, and physical abuse occurring before the age of 16, and disability in activities of daily living and instrumental activities of daily living in adulthood were collected. Multivariable logistic regression analyses were conducted. RESULTS: After adjusting for age, sex, and ethnicity, we found a positive association between different types of childhood abuse and adulthood disability: sexual talk (OR 1.54; 95% CI 1.27-1.85); sexual touching (OR 1.82; 95% CI 1.49-2.22); sexual intercourse (OR 2.58; 95% CI 1.75-3.81); physical abuse (OR 2.84; 95% CI 2.20-3.68). Increasing number of types of childhood abuse was associated with increased odds of adulthood disability. The odds of adulthood disability was increased for individuals who experienced all types of childhood abuse versus no childhood abuse (OR 3.59; 95% CI 1.64-7.84). Finally, the association between any childhood abuse and adulthood disability was largely explained by anxiety disorder, number of chronic physical conditions, and loneliness. CONCLUSIONS: Childhood abuse is positively associated with adulthood disability in England. Future longitudinal studies are warranted to understand the potentially complex interplay of factors that may increase risk for disability in individuals who experienced childhood abuse.

Association between intelligence quotient and disability: The role of socioeconomic status.

BACKGROUND: No study has investigated the association between intelligence quotient (IQ) and disability (i.e., difficulties in activities of daily living [ADL] or instrumental activities of daily living [IADL]) in the general population. OBJECTIVE: The goal of this nationally representative study was to analyse the potential IQ-disability association in England and identify influential factors in this association. METHODS: Cross-sectional data were analyzed from the 2007 Adult Psychiatric Morbidity Survey (n=6872). IQ was assessed by using the National Adult Reading Test, which consists of a list of 50 words and is scored by counting the number of errors in reading the words aloud. Disability was defined as difficulties in at least 1 of the 7 domains of ADL and IADL. Regression and mediation analyses were conducted to analyze the association between IQ and disability and identify potential factors involved in this relationship, estimating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among the 6872 participants, the mean (SD) age was 46.9 (18.9) years; 51.8% were women. The prevalence of disability increased from 27.7% with IQ 120-129 to 51.0% with IQ 70-79. After adjusting for sex, age and ethnicity, as compared with IQ 120-129, with IQ 110-119, 100-109, 90-99, 80-89, and 70-79, the probability of disability was increased (OR 1.22 [95% CI 1.01-1.48], 1.42 [1.16-1.72], 1.86 [1.54-2.25], 2.41 [1.92-3.03], and 4.71 [3.56-6.17], respectively). In addition, we found a positive association between a 1-SD decrease in IQ and disability (OR 1.53, 95% CI 1.43-1.63). Finally, income (mediated percentage 26.9%), social class (18.0%) and education (11.6%) strongly affected the IQ-disability association, and these socioeconomic factors collectively explained 37.1% of the association. CONCLUSIONS: Low IQ was positively associated with disability in England, and socioeconomic status explained more than one-third of this relationship.

Patient acceptable symptom state and minimal clinically important difference for patient-reported outcomes in systemic sclerosis: A secondary analysis of a randomized controlled trial comparing personalized physical therapy to usual care.

BACKGROUND: To estimate patient acceptable symptom state (PASS) and minimal clinically important difference (MCID) for patient-reported outcomes in systemic sclerosis (SSc). METHODS: We conducted a secondary analysis of the SCLEREDUC trial, a 12-month randomized controlled trial comparing the efficacy of physical therapy to usual care in 220 SSc patients followed-up from September 2005 to October 2010. Self-rated state and change in patient health at 12 months were assessed by using 2 external anchors extracted from the Medical Outcomes Study 36-Item Short-Form. Patients who self-rated their health as "excellent", "very good" or "good" were the PASS group and those who self-rated their health change as "somewhat better" were the MCID group. Main outcomes were the estimates of PASS by using the 75th percentile method and of MCID by using the mean change in scores method for pain and activity limitation. RESULTS: PASS (95% confidence interval) and mean (SD) MCID estimates at 12 months were 53.75 (34.00 to 68.00) and -6.74 (32.02) for the joint-pain visual analog scale (range 0-100), 1.41 (1.13 to 1.63) and -0.21 (0.48) for the Health Assessment Questionnaire (HAQ, range 0-3), 1.27 (1.07 to 1.62) and -0.13 (0.45) for the scleroderma HAQ (range 0-3), 26.00 (17.00 to 37.00) and -3.38 (9.87) for the Cochin Hand Function Scale (range 0-90), and 19.40 (17.20 to 21.90) and -5.69 (6.79) for the McMaster-Toronto Arthritis Patient Preference Disability Questionnaire (range 0-30), respectively. CONCLUSIONS: We provide, for the first time, the PASS and MCID estimates for pain and activity limitation in SSc. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00318188. First Posted: April 26, 2006.

Isokinetic assessment of trunk muscles in facioscapulohumeral muscular dystrophy type 1 patients.

Facioscapulohumeral muscular dystrophy type 1 is the third most common inherited myopathy. Its severity is proportionate to the loss of microsatellite D4Z4 repetitions, which are below 10. Patients suffer from weakness in facial muscles, shoulder girdles and ankle dorsiflexors. Trunk impairment is reported in few studies. To assess correlation between D4Z4 number of repetitions in facioscapulohumeral muscular dystrophy type 1 patients and trunk extensors and flexors isokinetic peak torque, 48 patients with southern Blot confirmed facioscapulohumeral muscular dystrophy type 1 were enrolled to perform clinical evaluation (Ricci's Clinical Severity Scoring, Berg Balance Scale, Functional Reach Test, timed up-and-go test, six-minute walk test, functional independence measure) and trunk isokinetic assessment. Trunk extensors and flexors isokinetic peak torque at 60°/sec were significantly correlated with number of D4Z4 microsatellite repetitions, sex, weight and age-independent (r = 0.391 [0.121; 0.662], p < 0.006 and r = 0.334 [0.028; 0.641], p < 0.033, respectively). Ricci's Clinical Severity Scoring was significantly correlated to trunk extensors isokinetic peak torque at 60°/sec, sex and weight-independent (r = -0.743 [-0.938; -0.548], p < 0.0001). This study demonstrates moderate correlation between pathologic compression of D4Z4 microsatellite array and trunk extensors isokinetic strength among facioscapulohumeral muscular dystrophy type I patients.

Effect of unloading brace treatment on pain and function in patients with symptomatic knee osteoarthritis: the ROTOR randomized clinical trial.

Evidence is still inconclusive for the benefits of bracing in patients with knee osteoarthritis. To assess the effect of REBEL RELIEVER unloading knee brace in conservative treatment of knee osteoarthritis, a randomized controlled trial was conducted in 67 patients with symptomatic medial knee osteoarthritis, who randomly received 6-week treatment with either REBEL RELIVER unloading knee brace + usual care (Brace group, N = 32) or usual care alone (Control group, N = 35). Primary outcome was the global last 24h-pain relief (100-mm visual analogic scale [VAS]) at 6 weeks. Secondary endpoints included pain on motion (100-mm VAS), function (Lequesne index), safety and observance. At 6 weeks, mean [SD] last 24h-pain decreased significantly more in Brace group versus Control group (-41.35 [3.37] vs -15.37 [3.23], difference -25.98, 95% CI -41.64 to -10.33, P < 0.0001). Higher mean [SD] pain on motion decrease (-51.91 [3.49] vs -19.91 [3.34], difference -32.01, 95% CI -48.21 to -15.80, P < 0.0001) and better improvement of Lequesne index score (-5.8 [0.5] vs -2.3 [0.5], difference -3.5, 95% CI -5.0 to -2.0, P < 0.0001) were observed in Brace group. Safety and observance to the brace were excellent. The additive clinical benefit of wearing REBEL RELIEVER unloading knee brace was demonstrated in knee osteoarthritis patients.

The benefits and tolerance of exercise in myasthenia gravis (MGEX): study protocol for a randomised controlled trial.

BACKGROUND: Research exploring the effects of physical exercise in auto-immune myasthenia gravis (MG) is scarce. The few existing studies present methodological shortcomings limiting the conclusions and generalisability of results. It is hypothesised that exercise could have positive physical, psychological as well as immunomodulatory effects and may be a beneficial addition to current pharmacological management of this chronic disease. The aim of this study is to evaluate the benefits on perceived quality of life (QOL) and physical fitness of a home-based physical exercise program compared to usual care, for patients with stabilised, generalised auto-immune MG. METHODS: MGEX is a multi-centre, interventional, randomised, single-blind, two-arm parallel group, controlled trial. Forty-two patients will be recruited, aged 18-70 years. Following a three-month observation period, patients will be randomised into a control or experimental group. The experimental group will undertake a 40-min home-based physical exercise program using a rowing machine, three times a week for three months, as an add-on to usual care. The control group will receive usual care with no additional treatment. All patients will be followed up for a further three months. The primary outcome is the mean change in MGQOL-15-F score between three and six months (i.e. pre-intervention and immediately post-intervention periods). The MGQOL-15-F is an MG-specific patient-reported QOL questionnaire. Secondary outcomes include the evaluation of deficits and functional limitations via MG-specific clinical scores (Myasthenia Muscle Score and MG-Activities of Daily Living scale), muscle force and fatigue, respiratory function, free-living physical activity as well as evaluations of anxiety, depression, self-esteem and overall QOL with the WHO-QOL BREF questionnaire. Exercise workload will be assessed as well as multiple safety measures (ECG, biological markers, medication type and dosage and any disease exacerbation or crisis). DISCUSSION: This is the largest randomised controlled trial to date evaluating the benefits and tolerance of physical exercise in this patient population. The comprehensive evaluations using standardised outcome measures should provide much awaited information for both patients and the scientific community. This study is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02066519 . Registered on 13 January 2014.

How far do stabilometric and clinical parameters correlate in peripheral neuropathies?

Peripheral neuropathies are characterized by the impairment of motor and sensitive nervous fibers. We aimed to investigate the correlation between proprioception, force and the limits of equilibrium parameter (LOE), by assessing 38 patients diagnosed with characterized bilateral neuropathy and 11 healthy subjects. Clinical evaluation, based on a motor and pallesthesic score, enabled their classification into groups corresponding to motor, sensitive or mixed neuropathies. Balance measures on a stabilometric platform allowed differentiation between the patients and healthy subjects but not between the groups of patients. The parameter limits of equilibrium (LOE) calculated as percentage of foot length allowed not only the differentiation between patients and healthy subjects but also between patients showing motor and sensitive forms. ROC analysis gave a threshold of 15% for LOE to discriminate between motor and sensory neuropathies with a 75% of sensitivity and 72% of specificity. Consequently, we propose a simple experimental procedure to carry out an accurate assessment of balance disorders in order to identify future rehabilitation modalities recommended to these patients.

Osteoarthritis of the knee and hip and activity: a systematic international review and synthesis (OASIS).

UNLABELLED: The goal of this study was to determine which activities in four domains, daily life, exercises, sports and occupational activities, should be recommended, in favor or against, for the patient suffering from knee or hip OA. METHODS: Scientific literature was searched in Medline, Embase and Cochrane databases for articles in French or English, reporting original data. The articles were evaluated with standardized epidemiological criteria. Seventy-two articles were retained. Recommendations were graded according to the level of scientific evidence (A high, B moderate, C clinical consensus) and were formulated for primary care. CONCLUSIONS AND RECOMMENDATIONS: For activity of daily life (ADL), the OASIS group states with a moderate level of scientific evidence, that ADL are a risk factor for knee OA and that risk increases with intensity and duration of activity. The group concludes that healthy subjects as well as OA patients in general can pursue a high level of physical activity, provided the activity is not painful and does not predispose to trauma (grade B). Radiographic or clinical OA is not a contraindication to promoting activity in patients who have a sedentary lifestyle (grade C). For exercises and other structured activities pursued with a goal of health improvement, the group states with a high level of scientific evidence that they have a favourable effect on pain and function in the sedentary knee OA patient. The OASIS group recommends the practice of exercises and other structured activities for the sedentary patient with knee OA (grade A). Static exercises are not favored over dynamic exercises, availability, preference and tolerance being the criteria for the choice of an exercise (grade A). As results deteriorate when exercises are stopped, they should be performed at a frequency of between one and three times per week (grade B). Professional assistance can be useful in improving initial compliance and perseverance (grade B). There is no scientific argument to support halting exercise in case of an OA flare-up (grade C). For sports and recreational activity, the group states with a high degree of scientific evidence, that these activities are a risk factor for knee and hip OA and that the risk correlates with intensity and duration of exposure. The group also states, with a high degree of scientific evidence, that the risk of OA associated with sport is lesser than that associated with a history of trauma and overweight. No firm conclusion could be drawn about the possible protective role of sports such as cycling, swimming or golf. The OASIS group recommends that athletes should be informed that joint trauma is a greater risk factor than the practice of sport (Grade A). The high level athlete should be informed that the risk of OA is associated with the duration and intensity of exposure (Grade B). The OA patient can continue to engage regularly in recreational sports as long as the activity does not cause pain (Grade C). The OA patient who practices a sport at risk for joint trauma should be encouraged to change sport (Grade C). For occupational activity, the OASIS group states with a high level of scientific evidence that there is a relationship between occupational activity and OA of the knee and hip. The precise nature of biomechanical stresses leading to OA remains unclear but factors such as high loads on the joint, unnatural body position, heavy lifting, climbing and jumping may contribute to knee and hip OA. The group recommends that taking an occupational history should always be part of managing the OA patient (Grade B). In the knee or hip OA patient, work-related activity that produces or maintains pain should be avoided (Grade B). Physicians should be alerted by the early knee and hip signs and symptoms in workers exposed to stresses that are known or supposed to favour knee or hip OA (Grade C).

Design of multiple axis robotic platform for postural stability analysis.

This paper presents the design and implementation of IsiMove, a new dynamic posturography platform. It allows the evaluation of the static and dynamic balance of a human placed on a force plate. IsiMove is a robotic platform open kinematic with four degrees of freedom: anteroposterior tilt, mediolateral tilt, vertical rotation, and horizontal translation. It is capable of measuring the displacement of the center of pressure over time, with a resolution of 0.1 mm for each foot and support a human of about 120 kg. IsiMove can generate various types of balance perturbations based on parameters such as direction, amplitude, frequency and shape. In this paper, we will give a description of the mechanisms that constitute our platform. First, the technical specifications of the hardware and software architecture will be presented. Then, we will provide details related to extensive experimental evaluations of the platform in both static and dynamic condition as well as result of postural stability analysis with healthy subjects and stroke patients.

Ankle dorsiflexion delay can predict falls in the elderly.

The aim of this study was to investigate the kinematic and kinetic characteristics of walking in healthy non-faller elderly in order to develop predictive parameters for falls. A 1-year prospective trial was completed on a walking circuit with two integrated force platforms and an optoelectronic system for three-dimensional movement analysis. Gait was investigated in 54 volunteers who were healthy people over 60 who had not fallen in the previous year. The subjects were contacted 2-monthly over a period of 1 year. The results showed that 16 of the 54 people tested had fallen. There was no significant age difference between the group of fallers and the group of non-fallers. Fallers walked more slowly and tended to use a double support for a longer period of time. Fallers were less powerful but mainly showed fewer power and moment variations. The range of motion at the ankle and the hip was reduced. We noticed a change in the walking pattern, showing a delay in the dorsiflexion of the ankle at the swing phase. In conclusion, subclinical gait parameters occur in older people. The advent of neuromotor pattern alterations when walking is related to the tendency to fall. Ankle dorsiflexion delays, in particular, appear to be predictive of falls.

Balance training in ataxic neuropathies. Effects on balance and gait parameters.

A rehabilitation program including foot sensory stimulation, balance and gait training with limited vision was followed by 30 patients with ataxic neuropathy in order to stimulate multi-sensory compensation in a no-controlled and no-blinded study. Ataxic neuropathy was graded by a pallesthetic score. The evaluation of patients and healthy subjects was performed with clinical tests (Berg Balance Scale, Functional Reach Test and Timed up and Go test) and instrumental tests for balance (force platform) and gait (Locometre). All patients exhibited impairments in balance and gait parameters compared to control group values. A high pallesthetic score correlated with increased sway area when standing with the eyes open on a firm surface. At the end of the training program, significant changes were observed in balance control assessed using the three clinical tests (Wilcoxon test, p<0.001). A tendency towards a reduction of the Romberg sign was noticed and limited changes were observed after training in instrumental tests for balance and for gait parameters. Age induced some limitations in balance and gait parameters but had no effect on training results. These results show that ataxic patients are impaired in balance and gait but can improve clinical balance parameters following training with a multisensory approach without limitation due to age or degree of sensory impairment. Only limited correlations were noticed between the pallesthetic score and some balance parameters, suggesting that various levels of compensation occur in these patients. The effectiveness of this training program has to be evaluated in the future in a controlled study to ascertain the contribution of the placebo effect in these data.

Musculo-tendinous stiffness of head-neck segment in the sagittal plane: an optimization approach for modeling the cervical spine as a single-joint system.

Despite the multi-linked architecture of the cervical spine, all previous studies that have made estimations of mechanical properties of the neck have considered the head-neck segment as a rigid link, with a fixed center of rotation at C7. The aim of this study was to consider the head-neck segment as a changeable geometry system for locating the resultant center of rotation and for calculating the musculo-tendinous stiffness by the quick-release method. Head kinematics during quick-releases was analyzed by recording the trajectory of surface markers. With an optimization procedure, the position of the resultant center of rotation of the head-neck segment was estimated. Thereafter, the angular displacement and acceleration of the head, together with the isometric torque developed by the cervical muscles were used to calculate the segment's stiffness. The results showed a consistent center of rotation and a significant increase of the musculo-tendinous stiffness with increasing torque.