Changes in postural and trunk muscles responses in patients with chronic nonspecific low back pain during sudden upper limb loading (original) (raw)
Related papers
Journal of Back and Musculoskeletal Rehabilitation, 2019
BACKGROUND: Changes in the motor control of the spine were found in patients with chronic low back pain (CLBP). Sudden loading of the spine is supposed to be the cause of about 12% of lower back injuries. However, some aspects of this problem, such as alterations in the sensory-motor control of the spine, remain questionable. OBJECTIVE: To investigate the effects of familiarization with loading, weight and size of loading on neuromuscular responses during sudden upper limb loading in CLBP patients. METHODS: In this quasi-experimental study surface electromyography of the erector spinae (ES) and transverses abdominis/internal oblique (TrA/IO) and external oblique (EOA) muscles were recorded in 7 men and 13 women with CLBP and 20 asymptomatic subjects (10 men and 10 women) aged 18-45 years from the general community familiarization. Moreover, investigating control of the posture measurements of the center of pressure (COP) and vertical ground reaction force (GRF) or Fz were recorded using a force plate. Data were analyzed using paired t-test and independent t-test with the significance level of 0.05. RESULTS: Data analyses were performed using SPSS version 18. Some electromyography and force plate variables were significantly different for different conditions in each group and between the asymptomatic and low back pain groups (p 0.05). CONCLUSION: Several motor control changes were observed in the CLBP patients. These patients showed decreased trunk muscle activity as well as too early and too delayed responses compared to asymptomatic subjects.
Journal of Electromyography and Kinesiology, 2011
Studies of electromyographic (EMG) activity and lumbopelvic rhythm have led to a better understanding of neuromuscular alterations in chronic low back pain (cLBP) patients. Whether these changes reflect adaptations to chronic pain or are induced by acute pain is still unclear. This work aimed to assess the effects of experimental LBP on lumbar erector spinae (LES) EMG activity and lumbopelvic kinematics during a trunk flexion-extension task in healthy volunteers and LBP patients. The contribution of disability to these effects was also examined. Twelve healthy participants and 14 cLBP patients performed flexionextension tasks in three conditions; control, innocuous heat and noxious heat, applied on the skin over L5 or T7. The results indicated that noxious heat at L5 evoked specific increases in LES activity during static full trunk flexion and extension, irrespective of participants' group. Kinematic data suggested that LBP patients adopted a different movement strategy than controls when noxious heat was applied at the L5 level. Besides, high disability was associated with less kinematic changes when approaching and leaving full flexion. These results indicate that experimental pain can induce neuromechanical alterations in cLBP patients and healthy volunteers, and that higher disability in patients is associated with decreased movement pattern changes.
Clinical Biomechanics, 1998
Objective. The purposes of this study were to examine coactivational activities of four trunk muscles in various static holding tasks, and to examine the differences of muscle activation patterns between normal subjects and low back pain (LBP) patients. Design. We used an one-way analysis of variance (anova) with repeated measures to analyze the effect of the knee angles, trunk flexion angles, and loading conditions on the amount of EMG activity. Background. Epidemiologic studies attribute a considerable proportion of the incidence of LBP to lifting-related injuries. The relationship between LBP and trunk muscles integrated electromyography (IEMG) is controversial. Methods. Relevance Several significant findings were identified in the study for clinical purposes. In addition, this study examined the feasibility of using surface EMG to measure muscle coactivation in functional posture of load holding.
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.
Trunk muscle co-ordination during gait: Relationship between muscle function and acute low back pain
Pathophysiology, 2005
Low back pain costs billions of Euros annually in all industrialized countries. Often radiological diagnosis fails to give evidence of the pathogenesis of low back pain. Although psychophysiological characteristics have an influence, it seems that insufficient muscular spinal stabilization may play the major role in the development of low back pain. Assessment of trunk muscle stabilization activity during everyday activities is rare. Therefore, in this study healthy persons were investigated during walking on a treadmill at a speed of 4 km/h. Women (n = 16) with no history of back pain were investigated before and after a static loading situation of the spine, i.e. while wearing a waistcoat. After this loading situation four women developed pain (pain subjects). Surface EMG (SEMG) was taken from five trunk muscles of both sides. Grand averaged amplitude curves over stride, amplitude normalized curves and variation between all included strides were calculated for all muscles and subjects, respectively. The normal range of all calculated parameters was defined within the span between the 5th and the 95th percentiles of all pain free subjects. Data were evaluated according to deviations from the normal range.
Neuromuscular Functional Assessment in Low Back Pain by Surface Electromyography (SEMG)
The Open Public Health Journal
Background: Low back pain is a major occupational health issue and a leading cause of disability globally. Significant differences in Surface Electromyography (SEMG) have been reported between persons with Low Back Pain (LBP) and normal, healthy controls. Many studies reveal that when the trunk is in full flexion there is an electrical silence in back muscles referred to as “flexion-relaxation phenomenon.” It is often absent in individuals reporting LBP and particularly chronic LBP. There are several SEMG measures that describe this phenomenon. Objective: To evaluate muscle activity in acute and chronic LBP and the usefulness of quick and reliable procedures to demonstrate abnormal electromyographic activity of the spine erector muscles. Methods: We evaluated 40 subjects aged 25-65 years. For each participant, a clinical history regarding the presence of chronic or acute LBP was collected. Each subject was evaluated with SEMG measures of spine erector muscles during standing and pro...
Journal of Electromyography and Kinesiology, 2013
Evidence indicates that previous low back injury (LBI) is a strong predictor for re-injury. The purpose of this study was to examine whether neuromuscular patterns remain altered in a LBI group who were deemed recovered. Surface electromyograms from 12-abdominal and 12-back extensors sites and motion variables were recorded from 33 LBI individuals (sub-acute phase) and 54 asymptomatic controls. Pain-related variables were recorded and a clinical assessment performed for LBI participants. Subjects performed a symmetrical lift and replace task in two reaches. Pattern recognition techniques were applied to normalized activation amplitude patterns to extract key recruitment strategies. Mixed model ANOVAs tested for effects (p < 0.05). Despite similar task performance, significantly (p < 0.05) different recruitment strategies were observed for the LBI group. There were higher activation amplitudes for LBI subjects in all muscles (except posterior external oblique) and greater co-activation between abdominal and back extensor sites compared to controls. Local abdominal and back extensor sites showed altered responses to increased physical demands in the LBI group. Despite outcomes indicating recovery, the LBI group had altered neuromuscular patterns compared to asymptomatic controls supporting that residual alterations remain following recovery.
Background: Pressure biofeedback unit (PBU) is a widely used non-invasive device for the monitoring of transverse abdominals (TA) and multifidus (MF) muscles in patients with low back pain (LBP). There is little research that compared trunk muscle activities with pressure feedback during trunk muscle contraction in a seated position. The aim this study was to compare muscle activities between deep local trunk muscles (TA and MF) and different target pressures (50, 60 and 70mmHg) of PBU in individuals with and without cLBP. Methods: Twenty-two patients with chronic LBP (cLBP) and 24 age matched healthy individuals were recruited. Electromyography (EMG) signals were recorded from the TA and MF muscles while the TA and MF were contracted to achieve PBU pressure value of 50, 60 and 70mmHg in random order. The average EMG amplitude (AEMG) of 3 replicate trials was used in the analysis after normalization to %MVIC. %MVIC is defined as the mean of the three AEMG divided by the AEMG of MVIC...