Shoulder and scapulothoracic impairments in women with breast cancer-related lymphedema in the upper limb: A cross-sectional study shoulder and breast cancer-related lymphedema.

INTRODUCTION: Lymphedema in the upper limb as a complication of breast cancer may lead to shoulder pain and dysfunctions. OBJECTIVE: To compare the scapular positioning, the shoulder range of motion, and muscle strength among women undergoing treatment for breast cancer with and without lymphedema and a control group. METHODS: This cross-sectional study evaluated women undergoing treatment for breast cancer (N = 25) and without lymphedema (N = 25), and a control group (N = 25). Static scapular positions and shoulder range of motion were measured by using an inclinometer. The shoulder and periscapular muscle strength were measured by using a hand-held dynamometer and the Disabilities of the Arm, Shoulder, and Hand Questionnaire was applied. Linear regression of the mixed effects model was used to compare the groups. RESULTS: Both groups of mastectomized women had reduced shoulder range of motion, scapular upward rotation, and muscle strength for shoulder and periscapular muscles compared to the control group. Also, women undergoing treatment for breast cancer with lymphedema had reduced shoulder range of motion, scapular upward rotation, increased anterior tilt, reduced muscle strength of the upper trapezius, and greater upper limb disability compared to women without lymphedema. CONCLUSION: Women undergoing treatment for breast cancer with lymphedema had even greater shoulder and scapulothoracic impairments when compared to the control group and women without lymphedema.

Risk and protective factors for shoulder complaints in indoor volleyball players: A comprehensive systematic review.

OBJECTIVE: This systematic review aimed to answer the question: "What are the risk and protective factors for shoulder complaints (pain, injury, or problem) in indoor volleyball players?". METHODS: Searches were conducted in electronic databases: PubMed/MEDLINE, Embase, CINAHL, and SPORTDiscus, as well as reference lists of the included studies. We included studies evaluating potential intrinsic and extrinsic factors associated with shoulder complaints in indoor volleyball players of any country, age, sex, and competitive level. The Quality in Prognosis Studies (QUIPS) tool was used to assess the risk of bias. RESULTS: The risk factors for shoulder complaints in volleyball players were identified through four prospective studies, which exhibited a moderate to low risk of bias. These factors included previous shoulder pain or injury, playing in outside and opposite positions, subacromial bursa thickening, and having an average external rotator (ER) isokinetic eccentric torque lower than the average internal rotator (IR) concentric torque. Protective factors were enhancing shoulder IR and ER isokinetic eccentric strength, being male sex, being older, and maintaining a concentric strength ratio ER/IR within the 0.60-0.75 range. CONCLUSIONS: This systematic review highlights risk factors that clinicians and researchers should consider when assessing and tracking indoor volleyball players.

Facilitators and barriers for adherence of shoulder pain patients to a home-based exercise program: cross-sectional study / Facilitadores e barreiras para a adesão de pacientes com dor no ombro a um programa de exercícios domiciliares: estudo transversal

ABSTRACT BACKGROUND AND OBJECTIVES: Home-based exercises can improve function and quality of life in shoulder pain patients. Knowing the facilitators and barriers is crucial for adherence to shoulder pain treatment. It is believed that individuals who adhere to home exercises have fewer environmental barriers, pain intensity and shoulder disability. The aim of this study is to identify facilitators and barriers for adherence to a home-based exercise program in shoulder pain individuals, and to investigate the influence of environmental barriers, shoulder pain and disability, and kinesiophobia on adherence to a program. METHODS: This is a cross-sectional study. Shoulder pain individuals performed home-based exercises for eight weeks based on a booklet in addition to supervised physical therapy or as their sole therapy. They reported the perceived facilitators and barriers to home exercises adherence and answered the Craig Hospital Inventory of Environmental Factors (CHIEF), Shoulder Pain and Disability Index (SPADI), and the Tampa Scale for Kinesiophobia (TSK) questionnaires. Logistic regression models analyzed the scores of the CHIEF, SPADI, and TSK as predictors of adherence. RESULTS: Fifty individuals participated in this study and 88% adhered to the program. The most frequent facilitator and barrier were "having guidance from a professional," and "lack of available time," respectively. Pain and disability were the only predictor of adherence (p=0.044), and an increase of one point in SPADI reduced the likelihood of adherence to home exercises by 14% (Exp(B) =0.86). CONCLUSION: Individuals reported facilitators and barriers to the exercise program. Environmental barriers assessed using the CHIEF and kinesiophobia were not predictors of adherence.

RESUMO JUSTIFICATIVA E OBJETIVOS: Os exercícios domiciliares podem melhorar a função e a qualidade de vida de pacientes com dor no ombro. Conhecer facilitadores e barreiras é fundamental para adesão ao tratamento da dor no ombro. Acredita-se que indivíduos que aderem aos exercícios domiciliares apresentem poucas barreiras ambientais, baixa intensidade de dor e incapacidade do ombro. O objetivo deste estudo foi identificar facilitadores e barreiras para a adesão a um programa de exercícios domiciliares em indivíduos com dor no ombro e investigar a influência de barreiras ambientais, da dor e incapacidade no ombro, e da cinesiofobia na adesão ao programa. MÉTODOS: Neste estudo transversal, indivíduos com dor no ombro realizaram exercícios domiciliares por oito semanas com base em uma cartilha além da fisioterapia supervisionada ou como sua única terapia. Os indivíduos relataram facilitadores e barreiras percebidos para a adesão aos exercícios em casa e responderam ao Craig Hospital Inventory of Environmental Factors-Brasil (CHIEF-Br), Shoulder Pain and Disability Index-Brasil (SPADI-Br) e Escala Tampa de Cinesiofobia (TAMPA). Os escores do CHIEF-Br, SPADI-Br e TAMPA foram analisados como preditores de adesão por meio de modelos de regressão logística. RESULTADOS: Participaram do estudo 50 indivíduos e 88% aderiram ao programa. O facilitador e a barreira mais frequentes foram "receber orientação de um profissional" e "falta de tempo disponível", respectivamente. Dor e incapacidade foram os únicos preditores de adesão (p=0,044), e o aumento de um ponto no SPADI-Br reduziu a probabilidade de adesão aos exercícios domiciliares em 14% (Exp(B) =0,86). CONCLUSÃO: Os indivíduos relataram facilitadores e barreiras ao programa de exercícios. A barreiras ambientais avaliadas por meio do CHIEF-Br e a cinesiofobia não foram preditores da adesão.

Laser-Pointer assisted angle reproduction test (LP-ART): reliability, performance, and correlation with shoulder pain and disability in patients with subacromial pain syndrome.

INTRODUCTION: The proprioception plays an important role in the stability of the shoulder joint. However, clinical practice lacks reliable and user-friendly tools. OBJECTIVES: To evaluate the intra- and inter-rater reliability of the Laser-Pointer assisted Angle Reproduction Test (LP-ART), to analyze the difference in proprioception between the symptomatic and asymptomatic shoulders, and to investigate if there is a correlation between the LP-ART and the pain intensity assessed by 11-point Numerical Rating Pain Scale (NRPS) and the level of shoulder disability and pain assessed by the Disability Index and Shoulder Pain (SPADI - BR). METHODS: Fifty patients (age = 56.2 ± 10.4 years) performed the LP-ART at 90° of shoulder flexion. RESULTS: The intra and interrater reliability of the LP-ART measurements was moderate (Intraclass Correlation Coefficient2,3 = 0.41 to 0.65) for both shoulders, symptomatic and asymptomatic. There was no difference in the absolute angular deviation between shoulders (mean difference of 0.4°, P = .581). The absolute angular deviation was not significantly correlated with the pain intensity (rs = 0.007, P = .962) and the SPADI - BR (rs = 0.022, P = .881). CONCLUSION: The LP-ART measurement showed moderate reliability in participants with subacromial pain syndrome. The active joint position sense was not different between symptomatic and asymptomatic shoulders, and there was no correlation between proprioception and the pain intensity and shoulder pain and disability level.

Noninvasive intracranial pressure monitoring in women with migraine.

This cross-sectional study aimed to compare the waveform morphology through noninvasive intracranial pressure (ICP-NI) measurement between patients with migraine and controls, and to analyze the association with clinical variables. Twenty-nine women with migraine, age 32.4 (11.2) years and headache frequency of 12.6 (7.5) days per month and twenty-nine women without headache, age 32.1 (9.0) years, were evaluated. Pain intensity, migraine disability, allodynia, pain catastrophizing, central sensitization and depression were evaluated. The ICP-NI monitoring was performed by a valid method consisting of an extracranial deformation sensor positioned in the patients' scalp, which allowed registration of intracranial pressure waveforms. Heart rate and blood pressure measurements were simultaneously recorded during 20 min in the supine position. The analyzed parameter was the P2/P1 ratio based on mean pulse per minute which P1 represents the percussion wave related to the arterial blood pression maximum and P2 the tidal wave, middle point between the P1 maximum and the dicrotic notch. There was no between-groups difference in the P2/P1 ratio (mean difference: 0.04, IC95%: -0.07 to 0.16, p = 0.352, F (1,1) = 0.881) adjusted by body mass index covariable. The Multiple Linear Regression showed non-statistical significance [F (5,44) = 1.104; p = 0.372; R2 = 0.11)] between the P2/P1 ratio and body mass index, presence of migraine, central sensitization, pain catastrophizing and depression. We found no correlation (p > 0.05) between P2/P1 ratio and migraine frequency, migraine onset, pain intensity, pain intensity at day of examination, disability, allodynia. Migraine patients did not present alterations in the waveform morphology through ICP-NI compared to women without headache and no association with clinical variables was found.

Impairment on Cardiovascular Autonomic Modulation in Women with Migraine.

Autonomic dysfunction, such as reduced vagally mediated heart rate variability, has been suggested in headache patients but is still uncertain when considering primary headache disorders. This study aims to compare the heart rate and blood pressure variability and baroreflex sensitivity between women with migraine and controls. A migraine (n = 20) and a control group (n = 20) of age-matched women without headache were evaluated. Heart rate variability was analyzed through frequency-domain using spectral analysis presenting variance, low-frequency (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.4 Hz) bands and by time domain (root mean square of successive R-R interval differences, RMSSD). Blood pressure variability was analyzed with spectral analysis and baroreflex sensitivity with the sequence method. Migraine group had lower heart rate variability characterized by a reduction in total variance, LF oscillations (sympathetic/vagal modulation) and HF oscillations (vagal modulation), and a reduction in SD and RMSSD compared to control group. No difference was found in the blood pressure variability analysis. Regarding baroreflex sensitivity, migraine group had decreased values of total gain, gain down and up compared to control group. Women with migraine exhibited autonomic modulation alterations, expressed by decreased values of heart rate variability and baroreflex sensitivity, but not by differences in blood pressure variability.

Effects on shoulder pain and disability of teaching patients with shoulder pain a home-based exercise program: a randomized controlled trial.

OBJECTIVE: To investigate the effect on shoulder pain and disability of teaching patients with shoulder pain how to undertake a home-based exercise program. DESIGN: A randomized controlled trial conducted from September 2015 to January 2016. SETTING: Participants' home. PARTICIPANTS: Sixty participants with shoulder pain who were waiting for physiotherapeutic treatment. INTERVENTIONS: The control group (n = 30) received minimal education about their shoulder condition and instructions to continue their activities as normal. The intervention group (n = 30) received a two-month home exercise program with one-hour sessions delivered by a physiotherapist to begin and one month after the program for exercise instructions. MAIN MEASURES: The primary outcome was change in the Shoulder Pain and Disability Index (SPADI). The secondary outcomes included change in the numeric pain rating scale and medication intake for pain relief. RESULTS: The patients' average age was 54.3 (13.8) years. SPADI scores at baseline were 60.9 (16.5) in the intervention and 64.7 (15.3) in the control group. After two months, the SPADI scores decreased to 18.8 (28.6) and to 61.4 (24.0), respectively, in the intervention and control groups with an estimated mean difference of 40.0, effect size: 1.61. The intervention group showed a reduced pain intensity (estimated mean difference: 3.7, effect size: 2.43) and medication intake (chi-square: 0.001). The number needed to treat was 1.2 for one patient to have a SPADI score <20. CONCLUSION: Teaching patients with shoulder pain how to undertake a home-based exercise program improved shoulder function and reduced pain intensity and medication intake over two months.

Comparison of the human-exosuit interaction using ankle moment and ankle positive power inspired walking assistance.

Previous ankle exoskeleton assistance techniques that were able to demonstrate metabolic reductions can be categorized into those that delivered moment profiles similar to the biological ankle moment throughout the stance phase, and others that delivered positive power only during push off. Both assistance techniques and a powered-off condition were compared in treadmill walking (1.5 m s-1) with a soft exosuit. We hypothesized that both techniques can result in a similar metabolic reduction when providing a similar level of average positive exosuit power at each ankle (0.12 W kg-1) and hip (0.02 W kg-1) while the underlying global center-of-mass and local joint biomechanics would be different. We found a similar net metabolic rate reduction of 15% relative to walking with the suit powered-off for both techniques. The ankle moment inspired technique showed larger magnitudes of reductions for biological moment and power at the hip and the ankle. The ankle power inspired technique might benefit from higher biological efficiency, when reducing positive instead of negative power at the knee and when almost keeping the isometric function of the plantarflexors before push-off. Changes at the ankle caused energetic reductions at the knee, hip and the center-of-mass. A major contribution to metabolic reduction might be based on them. As the lower limb biomechanics that led to these reductions were different, we believe that humans alter their gait to maximize their energetic benefit based on the exosuit assistance. For further insights on mechanisms that lead to metabolic reduction, joint mechanics and muscle-tendon dynamics must be analyzed in combination.

Scapulothoracic kinematic pattern in the shoulder pain and scapular dyskinesis: A principal component analysis approach.

The relationship between shoulder pain and scapular dyskinesis (SDK) is unclear. Differences between groups with and without SDK have been demonstrated, focusing on the amount of scapular motion at specific degrees of humeral elevation. However, this approach does not consider the temporal information and shape of the scapular motion temporal series. Principal Component Analysis (PCA) may clarify this variability and advance current understanding of 'abnormal' movement patterns. This study aimed to evaluate the scapular kinematics in patients with shoulder pain and in asymptomatic participants with and without SDK using PCA. Data were collected in 98 participants separated in four groups: Pain + SDK (n = 24), Pain (n = 25), No Pain + SDK (n = 24), and No Pain (n = 25). Scapulothoracic kinematic data were measured with an electromagnetic tracking device during arm elevation and lowering phases. PCA and analysis of variance were used to compare the groups. The No Pain + SDK group had a progressive increasing in anterior tilt over the elevation phase compared to the Pain (effect size = 0.79) and No Pain (effect size = 0.80) groups. During the arm-lowering, the Pain + SDK group had a progressive increasing in anterior tilt over this phase in comparison to the No Pain + SDK group (effect size = 0.68). Therefore, PCA demonstrated differences in the scapular anterior tilt related to SDK and shoulder pain. The presence of SDK revealed a scapular pattern with progressive increasing in anterior tilt over the elevation phase. However, during the arm-lowering phase, asymptomatic participants with SDK changed their motion pattern, unlike the symptomatic group, reinforcing the suggested association between scapular modifications and shoulder symptoms.

Immediate effect of scapula-focused exercises performed with kinematic biofeedback on scapular kinematics in individuals with subacromial pain syndrome.

BACKGROUND: Given the changes in the patterns of muscular activation and scapular movement in individuals with subacromial pain syndrome, the use of neuromuscular training has been considered in rehabilitation protocols. There is currently no evidence of the effects of the use of three-dimensional (3D) kinematic biofeedback on individuals with subacromial pain syndrome. This study aimed to determine the immediate effect of scapular motor control exercises using 3D kinematic biofeedback on the scapular kinematics, inter-segment coordination and pain of individuals with subacromial pain syndrome. METHOD: The kinematics of the scapulothoracic joint of 26 subjects with subacromial pain syndrome were assessed in the movement arm elevation and lowering in the sagittal plane before and after performance of three scapula-focused exercises using kinematic biofeedback. The individuals were familiarized with the selected exercises to acquire a greater scapular posterior tilt, while kinematic biofeedback, with visual and auditory stimuli, was used in real time. Scapular kinematics, pain, and subjective perception of exertion were the pre- and post-test measures. FINDINGS: In the movement of arm elevation and lowering, no differences were found in scapular tilt and on coordination between the segments pre- and post-test and the effect size was considered small. INTERPRETATION: Our results demonstrate that the performance of scapula-focused exercises using kinematic biofeedback does not cause immediate changes in the magnitude of scapular movement. However, inter-segmental coordination showed evidence of changes for scapular tilt in the lowering of the arm and internal rotation in the elevation and the lowering of the arm in individuals with subacromial pain syndrome.

Lower limb biomechanical analysis during an unanticipated step on a bump reveals specific adaptations of walking on uneven terrains.

Although it is clear that walking over different irregular terrain is associated with altered biomechanics, there is little understanding of how we quickly adapt to unexpected variations in terrain. This study aims to investigate which adaptive strategies humans adopt when performing an unanticipated step on an irregular surface, specifically a small bump. Nine healthy male participants walked at their preferred walking speed along a straight walkway during five conditions: four involving unanticipated bumps of two different heights, and one level walking condition. Muscle activation of eight lower limb muscles and three-dimensional gait analysis were evaluated during these testing conditions. Two distinct adaptive strategies were found, which involved no significant change in total lower limb mechanical work or walking speed. An ankle-based strategy was adopted when stepping on a bump with the forefoot, whereas a hip-based strategy was preferred when stepping with the rearfoot. These strategies were driven by a higher activation of the plantarflexor muscles (6-51%), which generated a higher ankle joint moment during the forefoot conditions and by a higher activation of the quadriceps muscles (36-93%), which produced a higher knee joint moment and hip joint power during the rearfoot conditions. These findings provide insights into how humans quickly react to unexpected events and could be used to inform the design of adaptive controllers for wearable robots intended for use in unstructured environments that can provide optimal assistance to the different lower limb joints.

Intrarater and interrater reliability of three classifications for scapular dyskinesis in athletes.

Clinical evaluation of scapular dyskinesis (SD) aims to identify abnormal scapulothoracic movement, underlying causal factors, and the potential relationship with shoulder symptoms. The literature proposes different methods of dynamic clinical evaluation of SD, but improved reliability and agreement values are needed. The present study aimed to evaluate the intrarater and interrater agreement and reliability of three SD classifications: 1) 4-type classification, 2) Yes/No classification, and 3) scapular dyskinesis test (SDT). Seventy-five young athletes, including 45 men and 30 women, were evaluated. Raters evaluated the SD based on the three methods during one series of 8-10 cycles (at least eight and maximum of ten) of forward flexion and abduction with an external load under the observation of two raters trained to diagnose SD. The evaluation protocol was repeated after 3 h for intrarater analysis. The agreement percentage was calculated by dividing the observed agreement by the total number of observations. Reliability was calculated using Cohen Kappa coefficient, with a 95% confidence interval (CI), defined by Kappa coefficient ±1.96 multiplied by the measurement standard error. The interrater analyses showed an agreement percentage between 80% and 95.9% and an almost perfect reliability (k>0.81) for the three classification methods in all the test conditions, except the 4-type and SDT classification methods, which had substantial reliability (k<0.80) in shoulder abduction. Intrarater analyses showed agreement percentages between 80.7% and 89.3% and substantial reliability (0.67 to 0.81) for both raters in the three classifications. CIs ranged from moderate to almost perfect categories. This indicates that the three SD classification methods investigated in this study showed high reliability values for both intrarater and interrater evaluation throughout a protocol that provided SD evaluation training of raters and included several repetitions of arm movements with external load during a live assessment.

Rate of force development and muscle activation of trunk muscles in women with and without low back pain: A case-control study.

OBJECTIVE: To evaluate the rate of force development (RFD) and the rate of electromyography rise (RER) of global and local trunk muscles in women with and without low back pain. DESIGN: Cross-sectional study. SETTING: Laboratory setting. PARTICIPANTS: Twenty-eight women divided into low back pain (LBP, n = 14) and control groups (CG, n = 14) participated in this study. MAIN OUTCOME MEASURES: Subjects performed isometric contractions of trunk using an isokinetic dynamometer, and simultaneously the electromyography (EMG) signals were collected for global (rectus abdominis and longissimus thoracic) and local (internal oblique and multifidus) muscles. All variables were calculated using Matlab software. RESULTS: Symptomatic subjects showed lower RFD during trunk extension and it was correlated to a reduced RER mainly in the trunk extensor musculature (p < 0.05). During trunk flexion, LBP exhibited a delayed time to reach peak RFD (p < 0.05) compared to CG. RER for global anterior muscle was higher than for local muscle (p < 0.05) and it was more persistent in asymptomatic women. CG also presented greater activation amplitude for both agonist and antagonist trunk muscles, mainly the global ones. CONCLUSION: Symptomatic women showed lower RFD and it was correlated to a reduced capacity of rapid muscle activation mainly in the trunk extensor musculature.

Continuous sweep versus discrete step protocols for studying effects of wearable robot assistance magnitude.

BACKGROUND: Different groups developed wearable robots for walking assistance, but there is still a need for methods to quickly tune actuation parameters for each robot and population or sometimes even for individual users. Protocols where parameters are held constant for multiple minutes have traditionally been used for evaluating responses to parameter changes such as metabolic rate or walking symmetry. However, these discrete protocols are time-consuming. Recently, protocols have been proposed where a parameter is changed in a continuous way. The aim of the present study was to compare effects of continuously varying assistance magnitude with a soft exosuit against discrete step conditions. METHODS: Seven participants walked on a treadmill wearing a soft exosuit that assists plantarflexion and hip flexion. In Continuous-up, peak exosuit ankle moment linearly increased from approximately 0 to 38% of biological moment over 10 min. Continuous-down was the opposite. In Discrete, participants underwent five periods of 5 min with steady peak moment levels distributed over the same range as Continuous-up and Continuous-down. We calculated metabolic rate for the entire Continuous-up and Continuous-down conditions and the last 2 min of each Discrete force level. We compared kinematics, kinetics and metabolic rate between conditions by curve fitting versus peak moment. RESULTS: Reduction in metabolic rate compared to Powered-off was smaller in Continuous-up than in Continuous-down at most peak moment levels, due to physiological dynamics causing metabolic measurements in Continuous-up and Continuous-down to lag behind the values expected during steady-state testing. When evaluating the average slope of metabolic reduction over the entire peak moment range there was no significant difference between Continuous-down and Discrete. Attempting to correct the lag in metabolics by taking the average of Continuous-up and Continuous-down removed all significant differences versus Discrete. For kinematic and kinetic parameters, there were no differences between all conditions. CONCLUSIONS: The finding that there were no differences in biomechanical parameters between all conditions suggests that biomechanical parameters can be recorded with the shortest protocol condition (i.e. single Continuous directions). The shorter time and higher resolution data of continuous sweep protocols hold promise for the future study of human interaction with wearable robots.

Peak torque, reaction time, and rate of torque development of hip abductors and adductors of older women.

Impaired muscle function at the hip has been implicated to be a major factor related to falls in older adults. Therefore, the aim of this study was to analyze the rate of torque development (RTD), reaction time (RT), and peak torque (PT) of hip abductors and hip adductors in young women (YW), older women nonfallers (ONF), and older women fallers (OF). Eighteen YW and 44 older women divided among OF (n = 20) and ONF (n = 24) performed maximum isometric hip abductor and adduction contractions on a dynamometer. YW had 40% greater PT and 61.5% greater RTD for hip abductors than the ONF. Compared with OF, YW had 47.5% greater PT and 68% greater RTD. OF showed less RTD at 150 ms (31%) and 200 ms (34.5%) than ONF for hip abductors. PT of hip adductors was 52% greater in YW than in the two older groups, whereas RTD was 71% greater. OF showed less RTD than ONF for hip abductors according to standardized effect sizes. No RT differences were observed between the three groups. We conclude that older women (OF and ONF) have less strength and ability to develop force rapidly than YW for hip abductors and adductors. Low hip strength and slowed force development in ONF during hip abduction may increase fall risk in older women.

Neuromuscular performance in the hip joint of elderly fallers and non-fallers.

BACKGROUNDS: Low strength and neuromuscular activation of the lower limbs have been associated with falls making it an important predictor of functional status in the elderly. AIM: To compare the rate of neuromuscular activation, rate of torque development, peak torque and reaction time between young and elderly fallers and non-fallers for hip flexion and extension. METHODS: We evaluated 44 elderly people who were divided into two groups: elderly fallers (n = 20) and elderly non-fallers (n = 24); and 18 young people. The subjects performed three isometric hip flexion and extension contractions. Electromyography data were collected for the rectus femoris, gluteus maximus and biceps femoris muscles. RESULTS: The elderly had 49 % lower peak torque and 68 % lower rate of torque development for hip extension, 28 % lower rate of neuromuscular activation for gluteus maximus and 38 % lower rate of neuromuscular activation for biceps femoris than the young (p < 0.05). Furthermore, the elderly had 42 % lower peak torque and 62 % lower rate of torque development for hip flexion and 48 % lower rate of neuromuscular for rectus femoris than the young (p < 0.05). The elderly fallers showed consistent trend toward a lower rate of torque development than elderly non-fallers for hip extension at 50 ms (29 %, p = 0.298, d = 0.76) and 100 ms (26 %, p = 0.452, d = 0.68).The motor time was 30 % slower for gluteus maximus, 42 % slower for rectus femoris and 50 % slower for biceps femoris in the elderly than in the young. DISCUSSION: Impaired capacity of the elderly, especially fallers, may be explained by neural and morphological aspects of the muscles. CONCLUSION: The process of senescence affects the muscle function of the hip flexion and extension, and falls may be related to lower rate of torque development and slower motor time of biceps femoris.

Discriminant analysis of neuromuscular variables in chronic low back pain.

BACKGROUND: Investigation and discrimination of neuromuscular variables related to the complex aetiology of low back pain could contribute to clarifying the factors associated with symptoms. OBJECTIVE: Analysing the discriminative power of neuromuscular variables in low back pain. METHODS: This study compared muscle endurance, proprioception and isometric trunk assessments between women with low back pain (LBP, n=14) and a control group (CG, n=14). Multivariate analysis of variance and discriminant analysis of the data were performed. RESULTS: The muscle endurance time (s) was shorter in the LBP group than in the CG (p=0.004) with values of 85.81 (37.79) and 134.25 (43.88), respectively. The peak torque (Nm/kg) for trunk extension was 2.48 (0.69) in the LBP group and 3.56 (0.88) in the GG (p=0.001); for trunk flexion, the mean torque was 1.49 (0.40) in the LBP group and 1.85 (0.39) in the CG (p=0.023). The repositioning error (degrees) before the endurance test was 2.66 (1.36) in the LBP group and 2.41 (1.46) in the CG (p=0.664), and after the endurance test, it was 2.95 (1.94) in the LBP group and 2.00 (1.16) in the CG (p=0.06). Furthermore, the variables showed discrimination between the groups (p=0.007), with 78.6% of the individuals with low back pain correctly classified in the LBP group. In turn, variables related to muscle activation showed no difference in discrimination between the groups (p=0.369). CONCLUSION: Based on these findings, the clinical management of low back pain should consist of both resistance and strength training, particularly in the extensor muscles.

Antagonist coactivation of trunk stabilizer muscles during Pilates exercises.

The purpose of this study was to compare the antagonist coactivation of the local and global trunk muscles during mat-based exercises of Skilled Modern Pilates. Twelve women performed five exercises and concurrently, surface EMG from internal oblique (OI), multifidus (MU), rectus abdominis (RA) and iliocostalis lumborum (IL) muscles was recorded bilaterally. The percentage of antagonist coactivation between local (OI/MU) and global muscles (RA/IL) was calculated. Individuals new to the practice of these exercises showed differences in coactivation of the trunk muscles between the exercises and these results were not similar bilaterally. Thus, in clinical practice, the therapist should be aware of factors such as compensation and undesirable rotation movements of the trunk. Moreover, the coactivation of global muscles was higher bilaterally in all exercises analyzed. This suggests that the exercises of Skilled Modern Pilates only should be performed after appropriate learning and correct execution of all principles, mainly the Centering Principle.

Variabilidade de parâmetros eletromiográficos e cinemáticos em diferentes condições de marcha em idosos / Electromyographic and kinematic parameters variability in different conditions of motion in the elderly

O objetivo deste estudo foi investigar a influência do medo de cair e da dupla tarefa sobre a variabilidade de parâmetros eletromiográficos e cinemáticos da marcha de idosas. Dezessete universitárias (21,47 ± 2,06 anos) e dezoito idosas (65,33 ± 3,14 anos), fisicamente ativas, realizaram teste de marcha em três condições: velocidade de preferência; medo de cair; e dupla tarefa. A atividade eletromiográfica dos músculos do membro inferior dominante e o comprimento e tempo de passada foram registrados. Utilizou-se o teste ANOVA Two-Way (p<0,05). A variabilidade eletromiográfica e cinemática foram maior para o grupo de idosas na comparação entre grupos. Para a comparação entre as condições de marcha analisadas, houve diferença significativa apenas para variabilidade eletromiográfica. Assim, o aumento da variabilidade dos parâmetros EMG e cinemáticos do grupo de idosos em relação ao grupo de jovens sugere que o fator envelhecimento contribui para uma maior dificuldade no controle da marcha, o que possivelmente predispõe estes indivíduos à ocorrência de quedas.

The main goal of this study was to investigate the influence of fear of fall and dual task on electromyographic and kinematic variability parameters on the gait of older females. Seventeen college students (21,47 ± 2,06 years old) and eighteen older female adults, both groups were physically fit and performed the gait test on three different conditions: walking at self-select speed, fear of fall and dual task. Electromyographic activity was measured on muscles of dominant leg and stride time was recorded. ANOVA two-way (p<0.05) was used. Electromyographic and kinematic gait variability were higher in older adult groups. However, for the comparison between gait conditions was only found significant difference for electromyographic variability. In line with this, the higher EMG and kinematic variability in older adults suggest that aging contributes for a higher motor challenge while walking, which may be predispose these individuals a higher risk of fall.