Bianca Callegari

Atividade eletromiográfica durante exercícios de propriocepção de tornozelo em apoio unipodal

Propriocepcao refere-se a percepcao dos mecanorreceptores para discriminar a posicao do corpo e movimentos articulares, bem como tensoes sobre os tendoes na fase estatica ou dinâmica da marcha. Objetivou-se avaliar por eletromiografia a ativacao muscular do gastrocnemio e tibial anterior em diferentes exercicios de propriocepcao do tornozelo em apoio unipodal, comparando graus de dificuldade. Foram selecionados 54 voluntarios, sedentarios, destros, do sexo masculino (20-35 anos). Exercicios foram feitos no balancinho, prancha de equilibrio, cama elastica e solo, a razao de tres repeticoes de 15 segundos cada, com intervalo de 15 segundos entre as repeticoes. Ao final dos testes os voluntarios indicaram a maior dificuldade. A atividade eletrica de ambos os musculos foi significativamente maior durante o teste no balancinho. No solo, ambos os musculos apresentaram menor atividade, mas apenas no gastrocnemio essa diferenca foi significativa. No exercicio na prancha de equilibrio e na cama elastica nao se encontrou diferenca quanto a ativacao dos musculos. Na analise intermusculo foi observada maior atividade do tibial anterior, exceto no balancinho. Assim, para o treino do apoio unipodal na aquisicao do ganho proprioceptivo, o equipamento adotado deve ser escolhido com cuidado: no balancinho e maior o recrutamento dos musculos tibial anterior e gastrocnemio, assim como e maior o grau de dificuldade para manutencao do equilibrio.

Barefoot Plantar Pressure Indicates Progressive Neurological Damage in Patients with Human T-Cell Lymphotropic Virus Type 1 Infection

Background The human T-Cell Lymphotropic Virus Type 1 (HTLV-1) is a retrovirus associated with neurological alterations; individuals with HTLV-1 infection may develop HTLV-1 associated myelopathy / tropical spastic paraparesis (HAM/TSP). Frequent neurological complaints include foot numbness and leg weakness. In this study, we compared the distribution of the body weight on different areas of the foot in HTLV-1 patients with HAM/TSP, asymptomatic HTLV-1 patients, and healthy individuals. Methodology We studied 36 HTLV-1 infected patients, who were divided in two groups of 18 patients each based on whether or not they had been diagnosed with HAM/TSP, and 17 control subjects. The evaluation included an interview on the patient’s clinical history and examinations of the patient’s reflexes, foot skin tactile sensitivity, and risk of falling. The pressure distribution on different areas of the foot was measured with baropodometry, using a pressure platform, while the patients had their eyes open or closed. Main Findings The prevalence of neurological disturbances—altered reflexes and skin tactile sensitivity and increased risk of falling—was higher in HTLV-1 HAM/TSP patients than in HTLV-1 asymptomatic patients. The medium and maximum pressure values were higher in the forefoot than in the midfoot and hindfoot in both HTLV-1 groups. In addition, the pressure on the hindfoot was lower in HAM/TSP patients compared to control subjects. Conclusions The neurological disturbances associated with HTLV-1 infection gradually worsened from HTLV-1 asymptomatic patients to HAM/TSP patients. Baropodometry is a valuable tool to establish the extent of neurological damage in patients suffering from HTLV-1 infection.

Anticipatory Postural Adjustments and kinematic arm features when postural stability is manipulated

Beyond the classical paradigm that presents the Anticipatory Postural Adjustments (APAs) as a manner to create forces that counteract disturbances arising from the moving segment during a pointing task, there is a controversial discussion about the role APAs to facilitate the movement and perform a task accurately. In addition, arm kinematics features are classically used to infer the content of motor planning for the execution and the control of arm movements. The present study aimed to disentangle the conflicting role of APAs during an arm-pointing task in which the subjects reach a central diode that suddenly turns on, while their postural stability was manipulated. Three postures were applied: Standing (Up), Sit without feet support (SitUnsup) and Sit with feet support (SitSup). We found that challenging postural stability induced an increase of the reaction time and movement duration (observed for the SitUnsup compared to SitSUp and Up) as well as modified the upper-limb velocity profile. Indeed, a greater max velocity and a shorter deceleration time were observed under the highest stability (SitSup). Thus, these Kinematics features reflect less challenging task and simple motor plan when the body is stabilized. Concerning the APAs, we observed the presence of them independently of the postural stability. Such a result strongly suggests that APAs act to facilitate the limb movement and to counteract perturbation forces. In conclusion, the degree of stability seems particularly tuned to the motor planning of the upper-limb during a pointing task whereas the postural chain (sitting vs. standing) was also determinant for APAs.

Comparison Between Transcutaneous Electrical Nerve Stimulation and Stabilization Exercises in Fatigue and Transversus Abdominis Activation in Patients With Lumbar Disk Herniation: A Randomized Study

Objective: The purpose of this study was to compare transcutaneous electrical nerve stimulation (TENS) and stabilization exercises in an attempt to prevent fatigue and improve muscle activation in patients with lumbar disk herniation associated with low back pain. Methods: This study involved 29 patients (age range 25–58 years) randomized into 2 groups: the segmental stabilization group (n = 15), who received stabilization exercises on the transversus abdominis (TrA) and lumbar multifidus muscles; and the TENS group (n = 14), who received electrotherapy. Groups underwent 16 sessions, for 60 minutes, twice per week, and they were evaluated before and after intervention. Pain was measured using a visual analog scale, functional disability using the Oswestry Disability Index, muscle activation and fatigue with electromyography, and patients’ ability to contract the TrA with a pressure biofeedback unit. Analyses within and between groups were performed. Results: The stabilization group improved lumbar multifidus fatigue (median frequency [MF] initial [P = .002], MF final [P < .001], MF slope [P = .001], and resistance time [P < .001]), ability to contract the TrA (P < .001), pain (P < .001), and functional disability (P < .001). TENS only was effective for pain (P = .012). Conclusion: Although it relieved pain, TENS was not effective as a single treatment to prevent fatigue, increase TrA contraction, and reduce functional disability in herniated disk patients. Stabilization exercises alone improved all measured outcomes.

Hip Rotations’ Influence of Electromyographic Activity of Gluteus Medius Muscle During Pelvic-Drop Exercise

CONTEXT Pelvic-drop exercises are often used to strengthen the gluteus medius (GM) muscle with the aim of increasing or prioritizing its recruitment. However, the effect of hip rotation on the performance of the action of the GM is unknown. OBJECTIVE To evaluate the effect of hip rotation on the recruitment of the GM, tensor fasciae latae (TFL), and quadratus lumborum (QL). METHOD Seventeen healthy subjects performed 2 sets of 4 repetitions of pelvic-drop exercise in random order with pelvic-drop lateral, medial, and neutral rotation of the hip. MAIN OUTCOME MEASURES The electromyographic (EMG) activity of the GM, TFL, and QL was evaluated using surface electromyography. RESULTS There were significant increases in the activation of the GM with medial and neutral rotation compared with lateral rotation (P = .03, P = .01, respectively), and there was no difference between medial and neutral rotation (P = 1.00). There was no difference in EMG activity of the TFL and QL in any of the positions. The GM:TFL ratio was the same in all analyzed positions. Regarding the GM:QL ratio, there was a significant increase with medial rotation compared with lateral rotation (P = .02). CONCLUSIONS Pelvic-drop exercises are more efficient for activating the GM when the hip is in medial rotation and neutral position.

Hand rest and wrist support are effective in preventing fatigue during prolonged typing

Study Design: Case series (longitudinal). Introduction: Only few reports concerning the efficacy of commonly used strategies for preventing upper limb occupational disorders associated with prolonged typing exist. Purpose of the Study: We aimed to investigate whether the duration of typing and the use of 2 strategies (hand rest and wrist support) changes muscle physiological response and therefore the electromyography records. Methods: We enrolled 25 volunteers, who were unfamiliar with the task and did not have musculoskeletal disorders. The subjects underwent 3 prolonged typing protocols to investigate the efficacy of the 2 adopted strategies in reducing the trapezius, biceps brachii, and extensor digitorum communis fatigue. Results: Typing for 1 hour induced muscular fatigue (60%‐67% of the subjects). The extensor digitorum communis muscle exhibited the highest percentage of fatigue (72%‐84%) after 1 and 4 hours of typing (1 hour, P = .04; 4 hours, P = .02). Fatigue levels in this muscle were significantly reduced (24%) with the use of pause typing (4 hours, P = .045), whereas biceps brachii muscle fatigue was reduced (32%) only with the use of wrist supports (P = .02, after 4 hours). Trapezius muscle fatigue was unaffected by the tested occupational strategies (1 hour, P = .62; 4 hours, P = .85). Discussion: Despite presenting an overall tendency for fatigue detected during the application of the protocols, the assessed muscles exhibited different behavior patterns, depending on both the preventive strategy applied and the muscle mechanical role during the task. Conclusion: Hand rest and wrist support can successfully reduce muscle fatigue in specific upper limb muscles during prolonged typing, leading to a muscle‐selective reduction in the occurrence of fatigue and thus provide direct evidence that they may prevent work‐related musculoskeletal disorders. Level of Evidence: N/A

Late physiotherapy rehabilitation changes gait patterns in post-stroke patients

Summary Study aim: To determine whether a physiotherapy protocol improves the electromyographic activation (EA) during the hemiparetic gait in patients with delayed access to rehabilitation. Material and methods: 40 post-stroke patients underwent clinical evaluation and gait assessment at the time of admission and at the end of treatment. Results: The anterior leg muscles tibialis anterior and rectus femoris had earlier onset (p = 0.0001). Conclusion: Electromyographic findings showed altered patterns during the hemiparetic gait cycle, even in patients with delayed access to treatment.

AB1163-HPR Effect of Stabilizing Exercises versus Tens in Fatigue of the Lumbar Multifidus Muscle and the Ability to Activate the Transversus Abdominis: A Preliminary Study

Background Chronic low back pain (cLBP) is defined as back pain lasting more than 12 weeks in the lumbar and sacral levels of the spine. The intervertebral disc herniation into the vertebral canal may cause pain and affects the transversus abdominis (TrA) and Lumbar Multifidus (ML) muscles that are preferentially attacked in episodes of nonspecific low back pain. Objectives Compare the effect of stabilizing exercises versus TENS in fatigue of the lumbar multifidus muscle (LM) and the ability to activate the transversus abdominis (TrA) in patients with lumbar disc herniation (LDH). Methods This study involved 29 patients (age range 25–58 years) randomised into two groups: Stabilisation group (SG: n=15); which received of stabilization exercises (transversus abdominis and lumbar multifidus muscles) and TENS group (TG: n=14), which received electrotherapy. Groups underwent 16 sessions, for 60 minutes, twice a week and they were evaluated before and after eight weeks. The following instruments were used: visual analogue pain scale and McGill Pain Questionnaire for pain, Oswestry Disability Index for functional disability, electromyography (EMG) to evaluate the LM and pressure biofeedback unit (PBU) for ability to contract the TrA. Analyses within and between groups were performed after treatment. One-way analysis of variance was used for intergroup and intragroup comparisons. Results The stabilisation group was superior to TENS in terms of improvements in fatigue of ML, pain, functional disability and ability to contract the TrA. There were no significant differences in TENS group in terms of disability or ability to contract the TrA muscle. Conclusions The stabilisation group was superior to TENS in improvements fatigue of ML, pain, functional disability and ability to contract the TrA. References Dedering A, Ringdahl KH, Ne`meth G. Back extensor muscle fatigue in patients with lumbar disc herniation, pre-operative and post-operative analysis of electromyography, endurance time and subjective factors, Eur Spine J, 2006, 15: 559–569. Cairms MC, Harrison K, Wright C. Pressure biofeedback: a useful tool in the quantification of abdominal muscular dysfunction? Physiother, 2000, 86(3): 127-38. Acknowledgements CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.2927

FRI0471-HPR Evaluation of muscle fatigue of lumbar multifidus and activation of transversus abdominis in subjects with lumbar disc herniation

Background Chronic low back pain (cLBP) is defined as back pain lasting more than 12 weeks in the lumbar and sacral levels of the spine. The intervertebral disc herniation into the vertebral canal may cause the pain and affects the transversus abdominis (TrA) and Lumbar Multifidus (ML) muscles that are preferentially attacked front episodes of nonspecific low back pain, promoting structural and morphological changes and difficulty in motor control. However, there is scarce literature that has evaluated the fatigue of ML and activation of TrA in individuals with lumbar disc herniation. Objectives To assess the fatigue of lumbar multifidus muscle and the ability of activation of transversus abdominis muscle in individuals with lumbar disc herniation. Methods This study examined 51 subjects divided into two groups: Lumbar disc herniation (LDH) (n=28, Mean age 44.79 (6.73), BMI 26.36 (2.79) and Control (without pain) (CG) (n=23, Mean age 39.22 (8.39), BMI 24.12 (2.14). Pain was evaluated withVisual Analogue Scale (VAS),functional disability with Oswestry disability questionnaire,the abilityof activation of TrA with pressure biofeedback unit (PBU), and back muscle fatigue (Lumbar multifidus muscle examined by the median frequency-MF) comprised an isometric endurance time (Sørensen’s test) with concomitant measures of electromyography. Intergroup statistical analysis was performed using the t test* and Mann- Whitney** for data with normal and without normal distribution respectively.A significance level was α=0.05. Results Lumbar multifidus muscle fatigue shows reduced spectrum of frequency (Hz) in both groups, however the LDH group presents more intense fatigue (MF Initial LDH - 155.8±3.07; CG - 179.6±21.13; p<0.001*/MF End LDH - 142.6±26.21; CG - 164.4±25.16; p =0.004*) and this occurs in shortest time (s) (LDH - 157.5±72.5; CG - 240±0; p<0.001**). The LDH group shows moderate pain (6.4±1.98) and minimal functional disability (17±3.02). In the activation of TrA, it shows lower values (LDH -1.19±1.24; CG -3.91±2.07;<0.001**). Conclusions The study suggests that LDH group have greater fatigue of lumbar multifidus muscle, lower endurance time and worse activation of TrA capacity when compared to individuals of Control group. References Awad JN, Moskovich R. Lumbar disc herniation. Clin Orthop Relat Res 2006; 443: 183-97. Elfving B, Ne’meth G, Arvidsson I. EMG spectral parameters and subjective rating of back muscle fatigue in healthy men and women. Scand J Rehabil Med. (2000) 32:117–123. Dedering A, Ringdahl KH, Ne’meth G. Back extensor muscle fatigue in patients with lumbar disc herniation, pre-operative and post-operative analysis of electromyography, endurance time and subjective factors, Eur Spine J, 2006, 15: 559–569. Cairms MC, Harrison K, Wright C. Pressure biofeedback: a useful tool in the quantification of abdominal muscular dysfunction? Physiother, 2000, 86(3): 127-38. Disclosure of Interest None Declared