A remote monitoring-enabled home exercise prescription for patients with interstitial lung disease at risk for exercise-induced desaturation.

RATIONALE: Alternatives to center-based pulmonary rehabilitation are needed to improve patient access to this important therapy. A critical challenge to overcome is how to maximize safety of unsupervised exercise for at-risk patients. We investigated if a novel remote monitoring-enabled mobile health (mHealth) program is safe, feasible, and effective for patients who experience exercise-induced hemoglobin desaturation. METHODS: An interstitial lung disease (ILD) commonly associated with pronounced exercise desaturation was investigated - the rare, female-predominant ILD lymphangioleiomyomatosis (LAM). Over a 12-week program, hemoglobin saturation (SpO2) was continuously recorded during all home exercise sessions. Intervention effects were assessed with 6-min walk test (6MWT), maximal cardiopulmonary exercise test (CPET), lower extremity computerized dynamometry, pulmonary function tests, and health-related quality of life (QoL) surveys. Safety was assessed by blood biomarkers of systemic inflammation and cardiac wall stress, and incidence of adverse events. RESULTS: Fifteen LAM patients enrolled and 14 completed the intervention, with high adherence to aerobic (87 ± 15%) and strength (87 ± 12%) training components. An innovative characterization of exercise training SpO2 revealed that while mild-to-moderate desaturation was common during home workouts, participants were able to self-adjust exercise intensity and supplemental oxygen levels to maintain recommended exercise parameters. Significant improvements included 6MWT distance (+36 ± 34 m, p = 0.003), CPET time (p = 0.04), muscular endurance (p = 0.008), QoL (p = 0.009 to 0.03), and fatigue (p = 0.001 to 0.03). Patient acceptability and satisfaction indicators were high, blood biomarkers remained stable (p > 0.05), and no study-related adverse events occurred. CONCLUSION: A remote monitoring-enabled home exercise program is a safe, feasible, and effective approach even for patients who experience exercise desaturation.

Causal mechanisms of a scapular stabilization intervention for patients with subacromial pain syndrome: a secondary analysis of a randomized controlled trial.

BACKGROUND: Causal mediation analysis is one way to bridge this gap by exploring the causal pathways of a given intervention. The aim of this study was to assess whether scapular motion, position, and periscapular muscle strength are mediators for pain and shoulder disability outcomes following a scapular stabilization intervention for patients with subacromial pain syndrome. METHODS: Sixty patients were randomized into two groups: scapular stabilization or periscapular strengthening exercises. The intervention consisted of three sessions per week for 8 weeks. The primary outcome measures were pain and disability and the following outcome measures were considered as potential mediators: scapular motion, scapular position, periscapular muscle strength, age, duration of symptoms, and side of the complaint. A model-based inference approach with bootstrap simulations was used to estimate the average causal mediation effect, average direct effect, and the average total effect from the data of a randomized clinical trial that evaluated the effect of adding scapular stabilization exercises to a scapulothoracic strengthening program in people with subacromial pain syndrome. RESULTS: The results demonstrated that none of the putative mediators were influenced by the intervention. However, muscle strength of serratus anterior, upper, middle, and lower trapezius muscles was associated with shoulder disability. CONCLUSION: Scapular kinematic and periscapular muscle strength did not mediate the effect of scapular stabilization exercises on shoulder pain or disability scores in subjects with subacromial pain syndrome. Muscle strength of serratus anterior, upper, middle and lower trapezius were associated with shoulder disability scores at 8-weeks follow-up.

Comparisons of physical exposure between workers harvesting apples on mobile orchard platforms and ladders, part 1: Back and upper arm postures.

This study compared farmworkers' exposure to non-neutral postures using a new mobile platform apple harvesting method and the traditional method using ladders. Twenty-four workers were recruited and assigned into three groups: ladder workers (n = 8) picking apples from full trees using a ladder, mobile platform workers (n = 8) picking apples from upper part of the trees while standing on a moving platform, and ground-based mobile platform workers (n = 8) picking apples from lower part of the trees which the mobile platform workers left out. Upper arm and back inclinations were continuously monitored during harvesting using tri-axial accelerometers over full work shifts (~8 h). Upper arm posture was characterized as the percentage of time that upper arm flexion and abduction exceeded 30°, 60°, and 90°. Back posture was characterized as the percentage of time that torso angles (sagittal flexion or lateral bending) exceeded 10°, 20°, and 30°. The 10th, 50th, and 90th postural percentiles were also calculated. The platform workers had lower exposures to upper arm flexion and abduction than the ground and ladder workers. There were no differences in torso angles between the ladder and mobile platform workers; however, the ground workers were exposed to more and greater percentages of time in torso flexions.

Comparisons of physical exposure between workers harvesting apples on mobile orchard platforms and ladders, part 2: Repetitive upper arm motions.

Farmworkers are exposed to physical risk factors including repetitive motions. Existing ergonomic assessment methods are primarily laboratory-based and, thus, inappropriate for use in the field. This study presents an approach to characterize the repetitive motions of the upper arms based on direct measurement using accelerometers. Repetition rates were derived from upper arm inclination data and with video recordings in the field. This method was used to investigate whether harvesting with mobile platforms (teams harvesting apples from the platform and the ground) increased the farmworkers' exposure to upper arm repetitive motions compared to traditional harvesting using ladders. The ladder workers had higher repetitive motions (13.7 cycles per minute) compared to the platform and ground workers (11.7 and 12.2 cycles per minutes). The higher repetitions in the ladder workers were likely due to their ability to work independently and the additional arm movements associated with ladder climbing and walking.

Effects of adding scapular stabilization exercises to a periscapular strengthening exercise program in patients with subacromial pain syndrome: A randomized controlled trial.

BACKGROUND: Interventions focused on the scapula should be considered in treating subacromial pain syndrome (SAPS). However, the effect of adding scapular stabilization exercises to protocols of progressive strengthening of the shoulder complex muscles on a non-multimodal approach remains unclear. OBJECTIVE: To investigate the effect of adding scapular stabilization exercises, emphasizing retraction, and depression of the scapula, to a progressive periscapular strengthening protocol on disability, pain, muscle strength, and ROM in patients with SAPS. DESIGN: Randomized, controlled, superiority trial, prospectively registered, two-arms, parallel, blind assessor, blind patient, and allocation concealment. METHODS: Sixty patients with SAPS were randomly allocated into two groups: Periscapular Strengthening (PSG) or Scapular Stabilization (SSG) exercises. The interventions were performed three times a week for eight weeks. The primary outcome function and secondary outcomes (Pain, kinesiophobia, global perceived effect, satisfaction with treatment, the range of motion, scapula position and muscle strength) were measured in the baseline, four weeks, eight weeks (end of intervention) and 16 weeks after baseline. Shoulder pain and function were assessed by the Brazilian version of the Shoulder Pain and Disability Index (SPADI-Br). RESULTS: A total of 60 patients were included and randomized to PSG (n = 30) or SSG (n = 30) from March 2016 to June 2017. There were no between group differences in primary and secondary outcomes at any time point. CONCLUSION: The inclusion of the isolated scapular stabilization exercises, emphasizing retraction and depression of the scapula, to a progressive general periscapular strengthening protocol did not add benefits to self-reported shoulder pain and disability, muscle strength, and ROM in patients with SAPS. TRIAL REGISTRATION: ClinicalTrials.gov.

Acute effect of flexible bar exercise on scapulothoracic muscles activation, on isometric shoulder abduction force and proprioception of the shoulder of individuals with and without subacromial pain syndrome.

BACKGROUND: There is currently no evidence about the effects of neuromuscular facilitation after the use of a flexible bar on scapulothoracic muscle activity in individuals with subacromial pain syndrome. The study aimed to assess the acute effect of flexible bar exercise and subjective fatigue on scapulothoracic muscle activity, shoulder proprioception, and shoulder abduction force of subjects with and without symptoms of subacromial pain syndrome. METHOD: Fifty subjects with subacromial pain syndrome and 50 asymptomatic subjects were recruited. A short-term flexible bar exercise was performed to assess the vibratory stimulus effects on scapulothoracic muscle activity, shoulder proprioception, and shoulder abduction force, and the same exercise was performed on a long-term basis to assess the effects of subjective fatigue. The activities of the serratus anterior and three portions of the trapezius muscle were investigated using surface electromyography during arm elevation. The active joint position sense error was assessed to determine shoulder proprioception using a laser pointer. A hand-held dynamometer was used to assess isometric shoulder abduction force. FINDINGS: No significant intra-group differences were found in scapulothoracic muscle activity, as well as in active joint position sense error and isometric shoulder abduction force in either group (p >0.05). INTERPRETATION: The acute effects of flexible bar exercise and subjective fatigue were unable to influence scapulothoracic muscle activation, shoulder joint position sense, and isometric shoulder abduction force in subacromial pain syndrome.

Scapular-focused exercise treatment protocol for shoulder impingement symptoms: Three-dimensional scapular kinematics analysis.

BACKGROUND: The present study aimed to describe the effects of a periscapular strengthening and neuromuscular training protocol in three-dimensional scapular kinematics and resting positioning in participants with shoulder impingement symptoms. Self-reported function was also evaluated. METHOD: The study group comprised 50 subjects with shoulder impingement syndrome (control group, n=25; treatment group, n=25). The treatment group underwent 8weeks of neuromuscular training and periscapular strengthening. Scapular kinematics was measured using an electromagnetic tracking device, and the Brazilian version of the Shoulder Pain and Disability Index (SPADI-Br) questionnaire was carried out before and after the treatment. FINDINGS: In the resting position, treated subjects had lower (p<0.01) internal rotation of the scapula compared to the control group, with a large effect size (2.4). On the coronal plane, the treated group had less scapular upward rotation (p<0.01) and less internal rotation (p<0.05), with a medium effect size. On the sagittal plane, the treated group had less internal rotation (p<0.01), less upward rotation (p<0.05), and less scapular anterior tilt (p<0.01), with a medium effect size. On the scapular plane, a reduction in upward rotation (p<0.01) after the intervention was observed, with a large effect size. Moreover, a reduction in the total SPADI-Br score was found, with a mean difference of 32.4 [24.4; 40.4] points (p<0.01) after the implementation of the protocol and a large effect size (2.0). INTERPRETATION: The results provide biomechanical support for the clinical rationale for indicating therapeutic exercises focused on the periscapular muscles to improve scapular dynamics.

Biomechanical Analysis of the Closed Kinetic Chain Upper-Extremity Stability Test.

CONTEXT: The closed kinetic chain upper-extremity stability (CKCUES) test is a functional test for the upper extremity performed in the push-up position, where individuals support their body weight on 1 hand placed on the ground and swing the opposite hand until touching the hand on the ground, then switch hands and repeat the process as fast as possible for 15 s. OBJECTIVE: To study scapular kinematic and kinetic measures during the CKCUES test for 3 different distances between hands. DESIGN: Experimental. SETTING: Laboratory. PARTICIPANTS: 30 healthy individuals (15 male, 15 female). MAIN OUTCOME MEASURES: Participants performed 3 repetitions of the test at 3 distance conditions: original (36 in), interacromial, and 150% interacromial distance between hands. Participants completed a questionnaire on pain intensity and perceived exertion before and after the procedures. Scapular internal/external rotation, upward/downward rotation, and posterior/anterior tilting kinematics and kinetic data on maximum force and time to maximum force were measured bilaterally in all participants. Percentage of body weight on upper extremities was calculated. Data analyses were based on the total numbers of hand touches performed for each distance condition, and scapular kinematics and kinetic values were averaged over the 3 trials. Scapular kinematics, maximum force, and time to maximum force were compared for the 3 distance conditions within each gender. Significance level was set at α = .05. RESULTS: Scapular internal rotation, posterior tilting, and upward rotation were significantly greater in the dominant side for both genders. Scapular upward rotation was significantly greater in original distance than interacromial distance in swing phase. Time to maximum force in women was significantly greater in the dominant side. CONCLUSION: CKCUES test kinematic and kinetic measures were not different among 3 conditions based on distance between hands. However, the test might not be suitable for initial or mild-level rehabilitation due to its challenging requirements.

Critical and Theoretical Perspective on Scapular Stabilization: What Does It Really Mean, and Are We on the Right Track?

Stabilization exercises have been a focus and mainstay of many therapeutic and performance training programs in the past decade. Whether the focus is core stabilization for the spine or scapular stabilization, clinicians and trainers alike have endorsed these programs, largely on the basis of conceptual theory and anecdotal experience. The notion that an unstable scapula is related to shoulder dysfunction and pathology is well accepted, but is it accurate? The aim of this perspective article is to challenge the concept of scapular stabilization through the application of biomechanical and motor control constructs. The objectives are to critically examine current beliefs about scapular stabilization, to discuss definitions of stabilization and stability in the context of the scapulothoracic region, and to evaluate key evidence regarding scapular stabilization and scapular dyskinesia. Several new approaches that may affect the understanding of normal and atypical scapula motion are explored. Finally, a historical analogy is presented and future research and clinical directions are suggested. The aims are to lead readers to the essential concepts implied on scapular stabilization, to increase the critical thought process in rehabilitation practice, and to suggest some open topics to be explored in future research.

Reliability of Electromagnetic Tracking of Scapular Orientation and Position in Healthy Sendentary Individuals / Confiabilidade da Avaliação da Orientação e Posição de Repouso da Escápula de Indivíduos Saudáveis e Sedentários com o Sistema Eletromagnético de Aquisição de Dados

Electromagnetic systems for motion analysis are claimed as a precise technique for tracking position and orientation of human body segments. To date, reliability electromagnetic tracking was described only for the dynamic assessment of the scapula motion, and no reliability studies on its resting posture or positioning were found. The aim of this study was to analyze intra- and inter-session reliabilities and absolute errors of the scapular orientation and position at habitual resting posture in healthy individuals. Twenty-two shoulder symptom-free individuals non participants in professional or recreational sports activities involving upper extremities were volunteers in this study. The equipment used was 3SPACE Liberty system (Polhemus Inc.). The same examiner collected the kinematic data from subjects in two different sessions, with an interval from seven to ten days. Intraclass Correlation Coefficient (ICC2,1 and ICC2, k) and Standard Error of Measurement (SEM) were calculated. Inter-session reliability ranged from good to excellent (ICC from 0.66 to 0.96) and intra-session reliability was excellent (ICC ≥ 0.97). SEM values found for linear distances were smaller than 0.02 cm and scapular rotations ranged from 0.72° to 5.48°. Results of this study demonstrated that electromagnetic data acquisition of scapula habitual posture is a reliable tool for defining scapular position and orientation in sedentary shoulder symptom-free individuals.

Sistemas eletromagnéticos para análise de movimento são conhecidos como precisos para registrar a posição e orientação dos segmentos do corpo humano. Até o momento, a confiabilidade do registro eletromagnético foi descrita apenas para a dinâmica da escápula, não sendo encontrados estudos de confiabilidade da posição de repouso ou postura da mesma. O objetivo deste estudo foi a análise da confiabilidade intra- e inter-sessão e erros absolutos do registro eletromagnético da posição e orientação da escápula na postura habitual de repouso de indivíduos saudáveis. Foram voluntários no estudo 22 indivíduos sem sintomas no complexo articular do ombro e não-praticantes amadores ou profissionais de esporte e atividade física envolvendo os membros superiores. O equipamento utilizado foi o sistema 3SPACE Liberty (Polhemus Inc.). Um mesmo avaliador coletou os dados cinemáticos em duas sessões diferentes com um intervalo de sete a dez dias. O Coeficiente de Correlação Intraclasse (ICC2,1 e ICC2,k) e o Erro Padrão de Medida (EPM) foram calculados. A confiabilidade inter-sessão variou entre boa a excelente (ICC de 0,66 a 0,96) e a confiabilidade intra-sessão foi sempre excelente (ICC ≥ 0,97). Os valores de EPM encontrados para as distâncias lineares foram menores que 0,02 cm e para as rotações da escápula relativa ao tórax variaram entre 0,72 º e 5,48 º. Os resultados deste estudo demonstraram que o registro eletromagnético da posição habitual de repouso da escápula é confiável para determinar a posição e a orientação da mesma em um população sedentária e sem sintomas no complexo articular do ombro.

Automation of workplace lifting hazard assessment for musculoskeletal injury prevention.

OBJECTIVES: Existing methods for practically evaluating musculoskeletal exposures such as posture and repetition in workplace settings have limitations. We aimed to automate the estimation of parameters in the revised United States National Institute for Occupational Safety and Health (NIOSH) lifting equation, a standard manual observational tool used to evaluate back injury risk related to lifting in workplace settings, using depth camera (Microsoft Kinect) and skeleton algorithm technology. METHODS: A large dataset (approximately 22,000 frames, derived from six subjects) of simultaneous lifting and other motions recorded in a laboratory setting using the Kinect (Microsoft Corporation, Redmond, Washington, United States) and a standard optical motion capture system (Qualysis, Qualysis Motion Capture Systems, Qualysis AB, Sweden) was assembled. Error-correction regression models were developed to improve the accuracy of NIOSH lifting equation parameters estimated from the Kinect skeleton. Kinect-Qualysis errors were modelled using gradient boosted regression trees with a Huber loss function. Models were trained on data from all but one subject and tested on the excluded subject. Finally, models were tested on three lifting trials performed by subjects not involved in the generation of the model-building dataset. RESULTS: Error-correction appears to produce estimates for NIOSH lifting equation parameters that are more accurate than those derived from the Microsoft Kinect algorithm alone. Our error-correction models substantially decreased the variance of parameter errors. In general, the Kinect underestimated parameters, and modelling reduced this bias, particularly for more biased estimates. Use of the raw Kinect skeleton model tended to result in falsely high safe recommended weight limits of loads, whereas error-corrected models gave more conservative, protective estimates. CONCLUSIONS: Our results suggest that it may be possible to produce reasonable estimates of posture and temporal elements of tasks such as task frequency in an automated fashion, although these findings should be confirmed in a larger study. Further work is needed to incorporate force assessments and address workplace feasibility challenges. We anticipate that this approach could ultimately be used to perform large-scale musculoskeletal exposure assessment not only for research but also to provide real-time feedback to workers and employers during work method improvement activities and employee training.

Can clinical observation differentiate individuals with and without scapular dyskinesis?

BACKGROUND: Altered scapular rotation and position have been named scapular dyskinesis. Visual dynamic assessment could be applied to classify this alteration based on the clinical observation of the winging of the inferior medial scapular border (Type I) or of the prominence of the entire medial border (Type II), or by the excessive superior translation of the scapula (Type III). OBJECTIVE: The aim of this study was to determine if there were differences in scapular rotations (Type I and II) and position (Type III) between a group of subjects with scapular dyskinesis, diagnosed by the clinical observation of an expert physical therapist, using a group of healthy individuals (Type IV). METHOD: Twenty-six asymptomatic subjects volunteered for this study. After a fatigue protocol for the periscapular muscles, the dynamic scapular dyskinesis tests were conducted to visually classify each scapula into one of the four categories (Type IV dyskinesis-free). The kinematic variables studied were the differences between the maximum rotational dysfunctions and the minimum value that represented both normal function and a small dysfunctional movement. RESULTS: Only scapular anterior tilt was significantly greater in the type I dyskinesis group (clinical observation of the posterior projection of the inferior angle of the scapula) when compared to the scapular dyskinesis-free group (p=0.037 scapular and p=0.001 sagittal plane). CONCLUSIONS: Clinical observation was considered appropriate only in the diagnoses of dyskinesis type I. Considering the lower prevalence and sample sizes for types II and III, further studies are necessary to validate the clinical observation as a tool to diagnose scapular dyskinesis.

Can clinical observation differentiate individuals with and without scapular dyskinesis? / O exame clínico de observação da discinese escapular é capaz de diferenciar portadores da disfunção dos normais?

Background: Altered scapular rotation and position have been named scapular dyskinesis. Visual dynamic assessment could be applied to classify this alteration based on the clinical observation of the winging of the inferior medial scapular border (Type I) or of the prominence of the entire medial border (Type II), or by the excessive superior translation of the scapula (Type III). Objective: The aim of this study was to determine if there were differences in scapular rotations (Type I and II) and position (Type III) between a group of subjects with scapular dyskinesis, diagnosed by the clinical observation of an expert physical therapist, using a group of healthy individuals (Type IV). Method: Twenty-six asymptomatic subjects volunteered for this study. After a fatigue protocol for the periscapular muscles, the dynamic scapular dyskinesis tests were conducted to visually classify each scapula into one of the four categories (Type IV dyskinesis-free). The kinematic variables studied were the differences between the maximum rotational dysfunctions and the minimum value that represented both normal function and a small dysfunctional movement. Results: Only scapular anterior tilt was significantly greater in the type I dyskinesis group (clinical observation of the posterior projection of the inferior angle of the scapula) when compared to the scapular dyskinesis-free group (p=0.037 scapular and p=0.001 sagittal plane). Conclusions: Clinical observation was considered appropriate only in the diagnoses of dyskinesis type I. Considering the lower prevalence and sample sizes for types II and III, further studies are necessary to validate the clinical observation as a tool to diagnose scapular dyskinesis. .

Contextualização: A movimentação ou posição alterada da escápula é definida como discinese escapular. O exame visual dinâmico pode ser utilizado para classificá-la de acordo com o julgamento clínico de projeção posterior excessiva da borda inferior medial (tipo I), da borda medial (tipo II) ou ainda translação excessiva no sentido cranial (tipo III). Objetivo: Determinar se há diferenças nas rotações escapulares (tipo I e II) e posição (tipo III) entre grupos de discinese e normais (tipo IV), os quais foram diagnosticados visualmente por um fisioterapeuta experiente. Método: Vinte e seis participantes assintomáticos foram voluntários neste estudo. Após um protocolo de fadiga periescapular, a avaliação dinâmica da discinese foi conduzida para classificar visualmente cada uma das escápulas em uma das quatro categorias (tipo IV - sem discinese). As variáveis cinemáticas estudadas foram a diferença entre o valor máximo indicativo da disfunção e o mínimo valor correspondente ao padrão normal esperado para o movimento ou o mínimo do próprio movimento disfuncional. Resultados: Apenas a inclinação anterior da escápula foi significantemente maior no grupo de discinese tipo I (observação visual de projeção posterior do ângulo inferior da escápula) quando comparada com o grupo sem discinese (p=0,037 plano escapular e p=0,001 plano sagital). Conclusões: A avaliação visual foi considerada apropriada apenas para o diagnóstico da discinese do tipo I. Considerando a baixa prevalência e o tamanho amostral dos tipos II e III, mais estudos são necessários para validar completamente a observação clínica como método adequado para o diagnóstico ...

Objective Assessment of Joint Stiffness: A Clinically Oriented Hardware and Software Device with an Application to the Shoulder Joint.

Examination of articular joints is largely based on subjective assessment of the "end-feel" of the joint in response to manually applied forces at different joint orientations. This technical report aims to describe the development of an objective method to examine joints in general, with specific application to the shoulder, and suitable for clinical use. We adapted existing hardware and developed laptop-based software to objectively record the force/displacement behavior of the glenohumeral joint during three common manual joint examination tests with the arm in six positions. An electromagnetic tracking system recorded three-dimensional positions of sensors attached to a clinician examiner and a patient. A hand-held force transducer recorded manually applied translational forces. The force and joint displacement were time-synchronized and the joint stiffness was calculated as a quantitative representation of the joint "end-feel." A methodology and specific system checks were developed to enhance clinical testing reproducibility and precision. The device and testing protocol were tested on 31 subjects (15 with healthy shoulders, and 16 with a variety of shoulder impairments). Results describe the stiffness responses, and demonstrate the feasibility of using the device and methods in clinical settings.

Upper extremity joint stresses during walkerassisted ambulation in post-surgical patients.

BACKGROUND: A walker is a common device prescribed for ambulatory assistance for individuals with balance difficulties or to reduce lower extremity demands following injury or surgery. The long-term use of a walker imposes significant demands on the patient's upper extremities that may lead to increased risk for development of secondary conditions such as wrist, elbow or shoulder pain. OBJECTIVE: To describe the joint kinematics, forces and moments of the wrist, elbow and shoulder in a sample of twenty patients that were using a walker as a result of total joint surgery of the hips and knees. METHODS: Three-dimensional upper extremity kinematics were recorded using a motion capture system synchronized with forces and torques transmitted through a walker instrumented with force transducers in the handles. RESULTS: Compressive forces were found to be nearly 20% of the body weight at each of the upper extremity joints, both surgical and non-surgical sides, being the greatest force at the wrist and decreasing proximally. Compression forces were greater in the non-surgical side limb at the wrist and at the elbow. CONCLUSION: Our findings indicated that loads on upper extremity joints associated with the use of a walker for assisted ambulation are high and further studies are needed to address the cause-effect relationship between the actual joint loading and the development of secondary musculoskeletal upper extremity complaints in more frail patients.

Upper extremity joint stresses during walkerassisted ambulation in post-surgical patients / Estresse articular no membro superior durante marcha assistida por andador em pacientes pós-cirúrgicos

BACKGROUND: A walker is a common device prescribed for ambulatory assistance for individuals with balance difficulties or to reduce lower extremity demands following injury or surgery. The long-term use of a walker imposes significant demands on the patient's upper extremities that may lead to increased risk for development of secondary conditions such as wrist, elbow or shoulder pain. OBJECTIVE: To describe the joint kinematics, forces and moments of the wrist, elbow and shoulder in a sample of twenty patients that were using a walker as a result of total joint surgery of the hips and knees. METHODS: Three-dimensional upper extremity kinematics were recorded using a motion capture system synchronized with forces and torques transmitted through a walker instrumented with force transducers in the handles. RESULTS: Compressive forces were found to be nearly 20 percent of the body weight at each of the upper extremity joints, both surgical and non-surgical sides, being the greatest force at the wrist and decreasing proximally. Compression forces were greater in the non-surgical side limb at the wrist and at the elbow. CONCLUSION: Our findings indicated that loads on upper extremity joints associated with the use of a walker for assisted ambulation are high and further studies are needed to address the cause-effect relationship between the actual joint loading and the development of secondary musculoskeletal upper extremity complaints in more frail patients.

CONTEXTUALIZAÇÃO: Um andador é um dispositivo frequentemente prescrito para auxiliar a marcha de indivíduos com dificuldades de equilíbrio ou para reduzir demandas à extremidade inferior após cirurgia ou lesão. O uso prolongado de um andador impõe significante demanda para a extremidade superior do paciente, o que pode levar a um risco aumentado de desenvolver condições secundárias, como dor no punho, cotovelo e ombro. OBJETIVO: Descrever a cinemática articular, forças e momentos do punho, cotovelo e ombro de uma amostra de 20 pacientes que faziam uso de um andador após cirurgia de substituição articular do joelho ou quadril. MÉTODOS: A cinemática tridimensional foi registrada usando um sistema de captura de movimento sincronizado com o registro de transdutores de força, que mediam a força transmitida através do andador. RESULTADOS: Este estudo revelou forças de até 20 por cento do peso corporal nos transdutores, com forças compressivas maiores do lado do membro inferior não operado, no punho e no cotovelo. CONCLUSÃO: Os achados indicam que demandas no membro superior associadas ao uso de andador como dispositivo auxiliar da marcha são grandes, e mais estudos são necessários para averiguar relações de causa-efeito entre as reais sobrecargas articulares e o desenvolvimento de queixas musculoesqueléticas no membro de pacientes em condições de debilidade.

Effects of progressive resistance strength training on knee biomechanics during single leg step-up in persons with mild knee osteoarthritis.

BACKGROUND: The goal of this study was to determine if increasing strength in primary knee extensors and flexors would directly affect net knee joint moments during a common functional task in persons with knee osteoarthritis. METHODS: An exploratory single sample clinical trial with pre-post treatment measures was used to study volunteers with clinical diagnosis of mild knee osteoarthritis (OA) in one knee. Subjects participated in an individually supervised training program 3 times a week for eight weeks consisting of progressive resistive exercises for knee extensors and knee flexors. Pre and post training outcome assessments included: 1. Net internal knee joint moments, 2. Electromyography of primary knee extensors and flexors, and 3. Self-report measures of knee pain and function. The distribution of lower extremity joint moments as a percent of the total support moment was also investigated. FINDINGS: Pain, symptoms, activities of daily life, quality of life, stiffness, and function scores showed significant improvement following strength training. Knee internal valgus and hip internal rotation moments showed increasing but non-statistically significant changes post-training. There were no significant differences in muscle co-contraction activation of the Quadriceps and Hamstrings. INTERPRETATION: While exercise continues to be an important element of OA management, the results of this study suggest improvements in function, pain, and other symptoms, as a result of strength training may not be causally related to specific biomechanical changes in net joint moments.

Activation of selected shoulder muscles during unilateral wall and bench press tasks under submaximal isometric effort.

STUDY DESIGN: Controlled laboratory study. OBJECTIVE: To assess the activation of 7 shoulder muscles under 2 closed kinetic chain (CKC) tasks for the upper extremity using submaximal isometric effort, thus providing relative quantification of muscular isometric effort for these muscles across the CKC exercises, which may be applied to rehabilitation protocols for individuals with shoulder weakness. BACKGROUND: CKC exercises favor joint congruence, reduce shear load, and promote joint dynamic stability. Additionally, knowledge about glenohumeral and periscapular muscle activity elicited during CKC exercises may help clinicians to design protocols for shoulder rehabilitation. METHODS: Using surface electromyography, activation level was measured across 7 shoulder muscles in 20 healthy males, during the performance of a submaximal isometric wall press and bench press. Signals were normalized to the maximal voluntary isometric contraction, and, using paired t tests, data were analyzed between the exercises for each muscle. RESULTS: Compared to the wall press, the bench press elicited higher activity for most muscles, except for the upper trapezius. Levels of activity were usually low but were above 20% maximal voluntary isometric contraction for the serratus anterior on both tasks, and for the long head triceps brachii on the bench press. CONCLUSIONS: Both the bench press and wall press, as performed in this study, led to relatively low EMG activation levels for the muscles measured and may be considered for use in the early phases of rehabilitation.

Maximal voluntary isometric elbow flexion force during unilateral versus bilateral contractions in individuals with chronic stroke.

The purpose of this study was to determine whether the phenomenon of bilateral deficit in muscular force production observed in healthy subjects and mildly impaired stroke patients also exists in patients with more chronic and greater levels of stroke impairment. Ten patients with chronic hemiparesis resulting from stroke performed unilateral and bilateral maximal voluntary isometric contractions of the elbow flexors. When the total force produced by both arms was compared, 12% less force was produced in the bilateral compared with unilateral condition (p=0.01). However, studying the effect of task conditions on each arm separately revealed a significant decline in nonparetic (p=0.01) but not paretic elbow flexor force in the bilateral compared with unilateral condition. Results suggest that a significant bilateral force deficit exists in the nonparetic but not the paretic arm in individuals with chronic stroke. Bilateral task conditions do not seem to benefit or impair paretic arm maximal isometric force production in individuals with moderate-severity chronic stroke.

Muscle activation profiles about the knee during Tai-Chi stepping movement compared to the normal gait step.

The purpose of this study was to investigate knee muscle activity patterns in experienced Tai-Chi (TC) practitioners during normal walking and TC stepping. The electromyographic (EMG) activity of vastus lateralis (VL), vastus medialis (VM), bicep femoris (BF), and gastrocnemius (GS) muscles of 11 subjects (five females and six males) during the stance phase of normal walking was compared to stance phase of a TC step. Knee joint motion was also monitored by using an Optotrak motion analysis system. Raw EMG was processed by root-mean-square (RMS) technique using a time constant of 50 ms, and normalized to maximum of voluntary contraction for each muscle, referred to as normalized RMS (nRMS). Peak nRMS and co-contraction (quantified by co-contraction index) during stance phase of a gait cycle and a TC step were calculated. Paired t-tests were used to compare the difference for each muscle group peak and co-contraction pair between the tasks. The results showed that only peak values of nRMS in quadriceps and co-contraction were significantly greater in TC stepping compared to normal walking (Peak values of nRMS for VL were 26.93% for normal walking and 52.14% for TC step, p=0.001; VM are 29.12% for normal walking and 51.93% for TC stepping, p=0.028). Mean co-contraction index for VL-BF muscle pairs was 13.24+/-11.02% during TC stepping and 9.47+/-7.77% in stance phase of normal walking (p=0.023). There was no significant difference in peak values of nRMS in the other two muscles during TC stepping compared to normal walking. Preliminary EMG profiles in this study demonstrated that experienced TC practitioners used relatively higher levels of knee muscle activation patterns with greater co-contraction during TC exercise compared to normal walking.