Changes in muscle activation patterns and subjective low back pain ratings during prolonged standing in response to an exercise intervention.
ABSTRACT Low back pain (LBP) development has been associated with occupational standing. Increased hip and trunk muscle co-activation is considered to be predisposing for LBP development during standing in previously asymptomatic individuals. The purpose of this work was to investigate muscle activation and LBP responses to a prescribed exercise program. Pain-developing (PD) individuals were expected to have decreased LBP and muscle co-activation following exercise intervention.
Electromyography (EMG) data were recorded from trunk and hip muscle groups during 2-h of standing. An increase of >10mm on visual analog scale (VAS) during standing was threshold for PD categorization. Participants were assigned to progressive exercise program with weekly supervision or control (usual activity) for 4 weeks then re-tested.
Forty percent were categorized as PD on day 1, VAS=24.2 (±4.0)mm. PD exercisers (PDEX) had lower VAS scores (8.93±3.66 mm) than PD control (PDCON) (16.5±6.3 mm) on day 2 (p=0.007). Male PDEX had decreased gluteus medius co-activation levels (p<0.05) on day 2.
The exercise program proved beneficial in reducing LBP during standing. There were changes in muscle activation patterns previously associated with LBP. Predisposing factors for LBP during standing were shown to change positively with appropriate exercise intervention.
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ABSTRACT: With the recent attention to 'sitting disease', health practitioners and scientists are promoting standing in the workplace to decrease sedentary time, despite a high prevalence of low back pain (LBP) development during prolonged standing. The purpose of this study was to assess how a seated break inserted between bouts of prolonged standing would influence LBP development, posture and movement. A total of 20 participants stood for 45 minutes, sat for 15 minutes and repeated this sequence while lumbar and thoracic angles were measured, and LBP visual analogue scale reports were taken. Of the sample, 55% participants reported LBP in standing. A stand to sit ratio of 3:1 did not provide lasting recovery of LBP from standing and pain developers utilised a limited range of their lumbar spine angle and increased thoracic extension, resulting in static postures that caused tissue aggravation that was not resolved after 15 minutes of sitting. Prolonged standing in the workplace has the potential to result in LBP for some workers and alternate ways to reduce sedentary time should be investigated.Ergonomics 04/2014; 57(4):555-62. · 1.67 Impact Factor
- Isokinetics and exercise science 03/2014; 22(2):145-151. · 0.61 Impact Factor
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ABSTRACT: Study Design. Longitudinal, Observational Objective: To determine if development of transient low back pain during prolonged standing in individuals without prior history of low back pain predicts future clinical low back pain development at higher rates than in individuals who do not develop low back pain during prolonged standing.Summary of Background Data. Prolonged standing has been found to induce transient low back pain in 40-70% of previously asymptomatic individuals. Individuals who develop pain during standing have been found to have altered neuromuscular profiles prior to the standing exposure compared to their pain free counterparts; therefore it has been hypothesized that these individuals may have higher risk for low back pain disorders.Methods. Previously asymptomatic participants who had completed a biomechanical study investigating low back pain development during standing and response to exercise intervention completed annual surveys regarding low back pain status for a period of 3-years. χ analyses were performed to determine group differences in low back pain incidence rates. Accuracy statistics were calculated for ability of low back pain development during standing to predict future low back pain.Results. Participants who developed transient low back pain during standing had significantly higher rates of clinical low back pain over the 3-year follow up period (35.3% vs 23.1%) and were 3 times more likely to experience an episode of clinical low back pain over the first 24 months than their non-pain developing counterparts.Conclusions. Transient low back pain development during prolonged standing is a positive predictive factor for future clinical low back pain in previously asymptomatic individuals. Individuals who experience transient low back pain during standing may be considered a 'pre-clinical' group who are at increased risk for future low back pain disorders.Spine 12/2013; · 2.16 Impact Factor