Individuals with chronic neck pain have lower neck strength than healthy controls : a systematic review with meta-analysis

The aim is to verify whether there is difference in neck strength between healthy individuals and individuals with chronic neck pain. Methods The PubMed, Embase, and Scopus databases were searched. Two independent reviewers selected relevant full articles comparing neck strength between healthy individuals and individuals with chronic neck pain. Two independent reviewers extracted the data from the full articles selected. A meta-analysis was used to assess standardized mean differences in neck strength based on a random-effects model (Prospero number CRD42017081502). Results The search returned 3554 results; 15 articles were included. The chronic neck pain group showed lower neck strength compared with healthy individuals. The standardized mean difference was -0.90 (95% confidence interval [CI] = -1.13 to -0.67) for flexion, -0.79 (95% CI = -0.99 to -0.60) for extension, -0.74 (95% CI = -1.03 to -0.45) for right lateral flexion, and -0.75 (95% CI = -1.04 to -0.46) for left lateral flexion. Conclusion Based on this meta-analysis with a 3a level of evidence, individuals with chronic neck pain have lower neck strength for flexion, extension, and the lateral flexion of the neck than healthy controls

Immediate effects of a lumbar spine manipulation on pain sensitivity and postural control in individuals with nonspecific low back pain: a randomized controlled trial

Background: According to the American Physical Therapy Association, there is strong evidence to show that vertebral mobilization and manipulation procedures can be used to improve spinal and hip mobility and reduce pain and incapacity in low back pain patients that fit the clinical prediction rule. Objectives: To evaluate the immediate effects of high-velocity low-amplitude (HVLA) manipulation on pain and postural control parameters in individuals with nonspecific low back pain. Methods: This study used a participant-blinded and assessor-blinded randomized controlled clinical trial involving a single session, in which 24 participants were randomly distributed into control (simulated manipulation) and intervention (HVLA lumbar manipulation) groups. The primary (pain: subjective pain intensity and pressure pain threshold) and secondary outcomes (postural control: ellipse area, center of pressure [COP] excursion, COP RMS velocity, and differences between the COP and center of projected gravity) were evaluated before and after the session using a numerical pain scale, algometer, and a force platform. For all outcomes, multiple mixed 2 (group) × 2 (time) ANOVAs were performed. Results: For the subjective pain intensity, only time was significant as a main effect, where pre-intervention presented a greater value then post-intervention (F [1.44] = 4.377; p = 0.042; r = 0.30). For the pressure pain threshold no significant effect was found. For the postural control parameters, as a main effect, only the ellipse area was significantly greater in the control group (F [1.44] = 6.760; p = 0.013; effect size = 0.36). Conclusions: There was a reduction in subjective pain intensity, evaluated using a numerical scale, in both the intervention and control groups immediately after the intervention, suggesting that the spinal manipulation had a similar effect to the placebo procedure. No effect of HVLA lumbar manipulation was identified for postural control variables in either the intervention or control groups

Força articular cervical e muscular durante exercícios do pescoço

A presente dissertação de mestrado teve como foco a avaliação dos aspectos biomecânicos, da coluna cervical e de exercícios do pescoço, associados à diminuição da ação dos flexores profundos e aumento da ação dos flexores superficiais. Estas mudanças nas ações musculares estão associadas a indivíduos com cervicalgia crônica e a investigação deste trabalho pode levar a uma melhor compreensão desta lesão e consequente melhor tratamento. Na busca desta meta foram desenvolvidos quatro estudos apresentados ao longo desta dissertação. Estudo 1: Uma revisão sistemática com metanálise comparando a capacidade de produção de força entre indivíduos com cervicalgia e indivíduos saudáveis. Para este estudo foram incluídos 20 artigos que compararam capacidade de produção de força entre os grupos, onde foi identificado que indivíduos com cervicalgia crônica apresentam menor capacidade de produção de força para flexão, extensão e flexão lateral direita e esquerda. Estudo 2: A partir do estudo 1 surgiu o estudo observacional desta dissertação o qual comparou a força dos flexores profundos e superficiais da coluna cervical e a força articular cervical durante exercícios de fortalecimento do pescoço através de um modelo biomecânico. Para este estudo 20 participantes foram avaliados durante exercícios dinâmicos e isométricos de flexão, extensão e flexão lateral direita. A carga do exercício foi definida em 15-25% da capacidade de produção de força pescoço e foram feitas 5 repetições para o exercício dinâmico e mantida por 10 segundos para o exercício isométrico. As forças musculares e articulares foram estimadas pelo modelo biomecânico Biomechanics of Bodies e as variáveis cinéticas e cinemáticas foram coletadas com o BTS Smart-DX. O exercício de flexão dinâmica apresentou os maiores valores de força para os flexores profundos ao mesmo tempo que os flexores superficiais não apresentaram diferenças entre a flexão isométrica e dinâmica. Estudo 3: Este estudo foi realizado visando dar maior segurança e robustez às respostas do modelo biomecânico do Estudo 2, correlacionando as respostas de força muscular, estimada com o modelo biomecânico, e a atividade muscular com eletromiógrafo, dos músculos esternocleidomastóides direito e esquerdo. As correlações se apresentaram em média excelentes tanto para o esternocleidomastoide direito (r=0.69±0.20) e esquerdo (r=0.71±0.22), estimulando a confiança nos resultados obtidos pelo modelo biomecânico para os músculos flexores profundos da cervical. Estudo 4: Este estudo avaliou diferentes métodos de contração voluntária isométrica máxima para normalizar o sinal eletromiográfico do esternocleidomastoide e escaleno anterior. Com base nos resultados deste estudo, o método proposto em flexão lateral com a cabeça rotada foi o que apresentou a maior ativação para o esternocleidomastoide e o método convencional a que apresentou a maior ativação para o escaleno anterior. Portanto é sugerido uma adaptação ao método apresentado na literatura para contração voluntária isométrica máxima do esternocleidomastoide. Com base nestes quatro estudos, podemos afirmar que indivíduos com cervicalgia apresentam menor capacidade de produção de força, mostrando a necessidade de exercícios de fortalecimento, além da função de hipoalgesia normal do exercício. Levando em conta a diminuição da força dos flexores profundos cervical e aumento da ativação dos flexores superficiais em indivíduos com cervicalgia crônica, o exercício de flexão cervical dinâmica parece ser o mais indicapado para o fortalecimento dos flexores profundos, ao mesmo tempo que reduz a ativação dos flexores superficiais.The present dissertation focused on the evaluation of the biomechanical aspects of the cervical spine and neck exercises, associated to the decrease of the action of the deep flexors and increase of the action of the superficial flexors. These changes in muscular actions are associated with individuals with chronic neck pain and the investigation of this work can lead to a better understanding of this lesion and consequent better treatment. In the pursuit of this aim, four studies were developed through this dissertation. Study 1: A systematic review with metanalysis comparing neck strength between individuals with neck pain and healthy controls. For this study, 20 articles comparing neck strength between groups and it was found that individuals with chronic neck pain have lower neck strength in flexion, extension, right and left lateral flexion. Study 2: From the development of study 1 came the observational study which compared the superficial, deep neck flexor muscle force and joint force during neck strengthening exercises using a biomechanical model. For this study, 20 participants were evaluated during dynamic and isometric exercises of flexion, extension and right lateral flexion. The exercise load was defined as 15-25% of the neck strength and 5 repetitions were made for the dynamic exercise and maintained for 10 seconds for the isometric exercise. Muscle and joint forces were estimated with the biomechanical model the Biomechanics of Bodies, and the kinetic and kinematic variables were collected using BTS Smart-DX. The dynamic neck flexion exercise showed the highest deep neck flexors muscle force values at the same time that the superficial neck flexors did not present differences between the isometric and dynamic flexion. Study 3: This study was carried out aiming at giving greater safety and robustness to the responses of the biomechanical model of Study 2, correlating the muscular force responses, estimated with the biomechanical model, and the muscular activity with electromyograph, of the right and left sternocleidomastoid muscles. Correlations were on average high for both right sternocleidomastoid (r = 0.69 ± 0.20) and left (r = 0.71 ± 0.22), ensuring the results obtained by the biomechanical model for the deep neck flexor muscles. Study 4: This study evaluated different methods of maximal isometric voluntary contraction to normalize the electromyographic signal of the sternocleidomastoid and anterior scalene. Based on the results of this study, the method proposed performing a lateral flexion with a rotated head was the one that presented the highest activation for the sternocleidomastoid however the conventional method was the one that presented the highest activation for the anterior scalene. Therefore, we suggest an adaptation to the method presented in the literature for the maximum voluntary isometric contraction of the sternocleidomastoid. Based on these four studies, we can affirm that individuals with neck pain have a lower neck strength, showing the need for strengthening exercises, in addition to the normal hypoalgesia function of the exercise. Regarding the decreased deep neck flexors force and increased superficial neck flexors force in individuals with chronic neck pain, the dynamic neck flexion exercise it seems to be the most suitable for the strengthening of deep flexors, while reducing the activation of the superficial flexors

Força articular cervical e muscular durante exercícios do pescoço

A presente dissertação de mestrado teve como foco a avaliação dos aspectos biomecânicos, da coluna cervical e de exercícios do pescoço, associados à diminuição da ação dos flexores profundos e aumento da ação dos flexores superficiais. Estas mudanças nas ações musculares estão associadas a indivíduos com cervicalgia crônica e a investigação deste trabalho pode levar a uma melhor compreensão desta lesão e consequente melhor tratamento. Na busca desta meta foram desenvolvidos quatro estudos apresentados ao longo desta dissertação. Estudo 1: Uma revisão sistemática com metanálise comparando a capacidade de produção de força entre indivíduos com cervicalgia e indivíduos saudáveis. Para este estudo foram incluídos 20 artigos que compararam capacidade de produção de força entre os grupos, onde foi identificado que indivíduos com cervicalgia crônica apresentam menor capacidade de produção de força para flexão, extensão e flexão lateral direita e esquerda. Estudo 2: A partir do estudo 1 surgiu o estudo observacional desta dissertação o qual comparou a força dos flexores profundos e superficiais da coluna cervical e a força articular cervical durante exercícios de fortalecimento do pescoço através de um modelo biomecânico. Para este estudo 20 participantes foram avaliados durante exercícios dinâmicos e isométricos de flexão, extensão e flexão lateral direita. A carga do exercício foi definida em 15-25% da capacidade de produção de força pescoço e foram feitas 5 repetições para o exercício dinâmico e mantida por 10 segundos para o exercício isométrico. As forças musculares e articulares foram estimadas pelo modelo biomecânico Biomechanics of Bodies e as variáveis cinéticas e cinemáticas foram coletadas com o BTS Smart-DX. O exercício de flexão dinâmica apresentou os maiores valores de força para os flexores profundos ao mesmo tempo que os flexores superficiais não apresentaram diferenças entre a flexão isométrica e dinâmica. Estudo 3: Este estudo foi realizado visando dar maior segurança e robustez às respostas do modelo biomecânico do Estudo 2, correlacionando as respostas de força muscular, estimada com o modelo biomecânico, e a atividade muscular com eletromiógrafo, dos músculos esternocleidomastóides direito e esquerdo. As correlações se apresentaram em média excelentes tanto para o esternocleidomastoide direito (r=0.69±0.20) e esquerdo (r=0.71±0.22), estimulando a confiança nos resultados obtidos pelo modelo biomecânico para os músculos flexores profundos da cervical. Estudo 4: Este estudo avaliou diferentes métodos de contração voluntária isométrica máxima para normalizar o sinal eletromiográfico do esternocleidomastoide e escaleno anterior. Com base nos resultados deste estudo, o método proposto em flexão lateral com a cabeça rotada foi o que apresentou a maior ativação para o esternocleidomastoide e o método convencional a que apresentou a maior ativação para o escaleno anterior. Portanto é sugerido uma adaptação ao método apresentado na literatura para contração voluntária isométrica máxima do esternocleidomastoide. Com base nestes quatro estudos, podemos afirmar que indivíduos com cervicalgia apresentam menor capacidade de produção de força, mostrando a necessidade de exercícios de fortalecimento, além da função de hipoalgesia normal do exercício. Levando em conta a diminuição da força dos flexores profundos cervical e aumento da ativação dos flexores superficiais em indivíduos com cervicalgia crônica, o exercício de flexão cervical dinâmica parece ser o mais indicapado para o fortalecimento dos flexores profundos, ao mesmo tempo que reduz a ativação dos flexores superficiais.The present dissertation focused on the evaluation of the biomechanical aspects of the cervical spine and neck exercises, associated to the decrease of the action of the deep flexors and increase of the action of the superficial flexors. These changes in muscular actions are associated with individuals with chronic neck pain and the investigation of this work can lead to a better understanding of this lesion and consequent better treatment. In the pursuit of this aim, four studies were developed through this dissertation. Study 1: A systematic review with metanalysis comparing neck strength between individuals with neck pain and healthy controls. For this study, 20 articles comparing neck strength between groups and it was found that individuals with chronic neck pain have lower neck strength in flexion, extension, right and left lateral flexion. Study 2: From the development of study 1 came the observational study which compared the superficial, deep neck flexor muscle force and joint force during neck strengthening exercises using a biomechanical model. For this study, 20 participants were evaluated during dynamic and isometric exercises of flexion, extension and right lateral flexion. The exercise load was defined as 15-25% of the neck strength and 5 repetitions were made for the dynamic exercise and maintained for 10 seconds for the isometric exercise. Muscle and joint forces were estimated with the biomechanical model the Biomechanics of Bodies, and the kinetic and kinematic variables were collected using BTS Smart-DX. The dynamic neck flexion exercise showed the highest deep neck flexors muscle force values at the same time that the superficial neck flexors did not present differences between the isometric and dynamic flexion. Study 3: This study was carried out aiming at giving greater safety and robustness to the responses of the biomechanical model of Study 2, correlating the muscular force responses, estimated with the biomechanical model, and the muscular activity with electromyograph, of the right and left sternocleidomastoid muscles. Correlations were on average high for both right sternocleidomastoid (r = 0.69 ± 0.20) and left (r = 0.71 ± 0.22), ensuring the results obtained by the biomechanical model for the deep neck flexor muscles. Study 4: This study evaluated different methods of maximal isometric voluntary contraction to normalize the electromyographic signal of the sternocleidomastoid and anterior scalene. Based on the results of this study, the method proposed performing a lateral flexion with a rotated head was the one that presented the highest activation for the sternocleidomastoid however the conventional method was the one that presented the highest activation for the anterior scalene. Therefore, we suggest an adaptation to the method presented in the literature for the maximum voluntary isometric contraction of the sternocleidomastoid. Based on these four studies, we can affirm that individuals with neck pain have a lower neck strength, showing the need for strengthening exercises, in addition to the normal hypoalgesia function of the exercise. Regarding the decreased deep neck flexors force and increased superficial neck flexors force in individuals with chronic neck pain, the dynamic neck flexion exercise it seems to be the most suitable for the strengthening of deep flexors, while reducing the activation of the superficial flexors

Comparison of low back mobility and stability exercises from Pilates in non-specific low back pain: A randomized controlled trial

Objectives: Compare the effects of the low back mobility and stability exercises from Pilates Method on low back pain, disability and movement functionality in individuals with non-specific chronic low back pain.Methods: 28 participants were randomized into two exercise protocol from Pilates methods, one focusing on low back stability and other on low back mobility. Low back pain (visual analogic scale), low back disability (Oswestry) and movement functionality (7 functional movement tasks) were evaluated before and after 10 sessions of Pilates exercise by the same trained assessor. A mixed designed ANOVA with two factors was used.&nbsp;Results: The results of the study showed that there was a significant improvement to the pain, disability and movement functionality after the intervention regardless the group and it wasn’t found significant interaction.Conclusions: Regardless the exercise protocols both improved all outcomes for individuals with non-specific chronic low back pain. Also, there is no difference between focus on mobility or stability in the application of Pilates exercises for those outcomes therefore, the indication of one exercise protocol or another may fall within the preference of the instructor or practitioner/patient.</p

Individual muscle force of the shoulder complex with different external loads and movements: a biomechanical simulation analysis

The analysis of the force produced by each muscle has great clinical relevance, guiding professionals to training or treatments that are more precise, specific, and individualized to structures and muscles of interest. The aim of this study was to estimate the individual muscle force of the shoulder complex during three shoulder movements with three different loads. Fifteen healthy male subjects with right upper limb dominance performed five repetitions of shoulder abduction, scapular plane elevation (scaption), flexion movement in 120° with a speed of 45°/s and the with a load defined as 5% of the subject weigth. The movements were evaluated in three situations: without external load, with dumbbell, and with elastic resistance. Dvideow software was used to analyze the kinematic data, and OpenSim software was used to estimate individual muscle force with an upper limb biomechanical model. Deltoid (anterior, middle and posterior), supraspinatus, infraspinatus, teres (major and minor), subscapularis, and long biceps brachii were estimated. For statistical analysis, a generalized estimating equation model was used with SPSS 20.0. Almost all muscles presented statistical differences (p<0.05) with varying loads in all tested movements. It can be concluded that despite the lack of validation for the present biomechanical model, we could see different individual muscle forces through different external loads identifying which exercise produce more force in certain muscles guiding a more specific rehabilitation/exercise program