Trunk muscle co-ordination during gait: Relationship between muscle function and acute low back pain (original) (raw)
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Journal of Orthopaedic Research, 2002
4bnormal patterns of trunk muscle activity could aKect the biomechanics of spinal movements and result in back pain. The present study aimed to examine electromyographic (EMG) activity of abdominal and back muscles as well as triaxial torque output during isometric axial rotation at different exertion levels in back pain patients and matched controls. Twelve back pain patients and 12 matched controls performed isometric right and left axial rotation at 100%, 70%, 50%) and 30% maximum voluntary contractions in a standing position. Surface EMG activity of rectus abdominis, external oblique, internal oblique, latissimus dorsi, iliocostalis lumborum and multifidus were recorded bilaterally. The primary torque in the transverse plane and the coupling torques in sagittal and coronal planes were measured. Results showed that there was a trend ( P = 0.08) of higher flexion coupling torque during left axial rotation exertion in back pain patients. Higher activity for external oblique and lower activity for multifidus was shown during left axial rotation exertion in back pain group when compared to the control group. In right axial rotation, back pain patients exhibited lesser activity of rectus abdominis at higher levels of exertion when compared with matched controls. These findings demonstrated that decreased activation of one muscle may be compensated by overactivity in other muscles. The reduced levels of activity of the multifidus muscle during axial rotation exertion in back pain patients may indicate that spinal stability could be compromised. Future studies should consider these alternations in recruitment patterns in terms of spinal stability and internal loading. The findings also indicate the importance of training for coordination besides the strengthening of trunk muscles during rehabilitation process.
Specificity of a Back Muscle Exercise Machine in Healthy and Low Back Pain Subjects
Medicine & Science in Sports & Exercise, 2010
Purpose: To determine whether dynamic back muscle endurance exercises in a semi-sitting position induce more fatigue in back muscles than in hip extensors in healthy controls as well as in patients with non-specific chronic low back pain. Methods: Sixteen healthy and 18 volunteers with non-specific chronic low back pain performed trunk flexion-extension cycles until exhaustion, at 60% of their strength, in a machine designed for back exercise in a semisitting position with knees' angle at 135°. The number of cycles and perceived muscle fatigue (Borg CR-10 scale) at five areas (upper and lower back, gluteus, hamstrings, quadriceps) were used as fatigue criteria. Electromyographic (EMG) signals were recorded bilaterally on four back muscles, two hip extensors (gluteus maximus, biceps femoris) and the vastus medialis. The slope values of the instantaneous median frequency values computed over time were retained as EMG indices of fatigue. Results: The number of cycles was equivalent in healthy controls (n = 23 ± 13) and patients with back pain (n = 27 ± 16). EMG indices of fatigue disclosed evidence of muscle fatigue in all back muscles and the vastus medialis, contrary to hip extensors. EMG revealed significantly more muscle fatigue of lower back muscles, which was further corroborated by the Borg scale assessment. No between-group difference was obtained in any EMG comparison. Conclusion: These results showed that this type exercise machine can specifically train the back muscles, and this as much in subjects with nonspecific chronic low back pain as in healthy controls. This has implications for the training of back muscle endurance, especially in patients with back pain for whom poor back muscle endurance is sometimes of concern.
Chronic low back pain and back muscle activity during functional tasks
Gait & posture, 2018
There is evidence that patients with low back pain favor their trunk muscles when moving. However, it is unknown whether this maladaptive behavior is generalized across different functional tasks. This study analyzed the back muscle activity of patients with chronic low back pain compared to asymptomatic controls during five functional tasks. The secondary aim of this study was to test whether the electromyographic activity of patients' back muscles was correlated with either the TAMPA scale score or the Örebro Questionnaire. Forty patients with chronic, non-specific low back pain and 40 asymptomatic participants were assessed on the electromyographic activity of the lumbar longissimus, ilio-costal and multifidus while picking up and placing an object on the ground, sitting down and standing up, and climbing stairs. There was statistical evidence of two-way interactions involving group by task (F = 7.921, p < 0.001, η = 0.049) and task by muscle (F = 2.912, p < 0.001, η = ...
Activation imbalances in lumbar spine muscles in the presence of chronic low back pain
Journal of applied physiology (Bethesda, Md. : 1985), 2003
Paraspinal electromyographic (EMG) activity was recorded bilaterally from three lumbar levels during 30-s isometric trunk extensions [40 and 80% of maximum voluntary contraction (MVC)] in 20 healthy men and 14 chronic low back pain patients in pain. EMG parameters indicating neuromuscular fatigue and contralateral imbalances in EMG root-mean-square amplitude and median frequency were analyzed. Patients in pain showed less fatigue than controls at both contraction levels and produced only 55% of their MVC. Patients in pain likely did not produce a "true" maximum effort. A low MVC estimate would mean lower absolute contraction levels and less neuromuscular fatigue, thus explaining lower scores in the patients. Contralateral root-mean-square amplitude imbalances were present in both categories of subjects although such imbalances, when averaged across lumbar levels, were significantly larger in patients. Median frequency imbalances were significantly larger in the patients, a...
Trunk muscle activation in low-back pain patients, an analysis of the literature
Journal of Electromyography and Kinesiology, 2003
This paper provides an analysis of the literature on trunk muscle recruitment in low-back pain patients. Two models proposed in the literature, the pain-spasm-pain model and the pain adaptation model, yield conflicting predictions on how low-back pain would affect trunk muscle recruitment in various activities. The two models are outlined and evidence for the two from neurophsysiological studies is reviewed. Subsequently, specific predictions with respect to changes in activation of the lumbar extensor musculature are derived from both models. These predictions are compared to the results from 30 clinical studies and three induced pain studies retrieved in a comprehensive literature search. Neither of the two models is unequivocally supported by the literature. These data and further data on timing of muscle activity and load sharing between muscles suggest an alternative model to explain the alterations of trunk muscle recruitment due to low-back pain. It is proposed that motor control changes in patients are functional in that they enhance spinal stability.
Journal of Modern Rehabilitation, 2022
The flexible-bar with a small amplitude of 5 Hz, which transmits vibrations to the trunk, enables the activation of the core muscles that can be used to rehabilitate subjects with low back pain. Two types of exercise direction that can affect trunk muscles of low back pain subjects similar control group are not known. This study aimed to evaluate and compare exercises with two directions of the oscillating flexible poles in people with and without low back pain (LBP). Materials and Methods: Twelve women with Mean±SD age of 28.75±2.92 years, and body mass index (BMI) of 22.31±2.10 kg/m 2 and a history of low back pain, and 12 healthy subjects with Mean±SD age of 28.75±2.49 years and BMI of 21.59±1.50 kg/m 2 voluntarily participated in this study. The electromyography (EMG) signals of trunk muscles were measured during two handheld oscillating flexible bars in two directions. The root means square (RMS) of signals for each muscle is normalized by the maximum RMS. Results: The results of comparing two types of exercise in two groups showed significant differences for left external oblique (P=0.017), right external internal oblique (0.002), and left internal oblique (0.008). Also, the difference in the interaction between group×exercise was significant only for left internal oblique (P=0.026). Conclusion: Muscle activity in the low back pain group appears different while performing exercises with a flexible-bar compared to the control group. This confirms motor control impairment in these populations and having different strategies for trunk co-activation during exercise.