Trunk Dynamic Stability Assessment for Individuals With and Without Nonspecific Low Back Pain During Repetitive Movement

Abstract

Objective This study aimed to employ nonlinear dynamic approaches to assess trunk dynamic stability with speed, symmetry, and load during repetitive flexion-extension (FE) movements for individuals with and without nonspecific low back pain (NSLBP). Background Repetitive trunk FE movement is a typical work-related LBP risk factor contingent on speed, symmetry, and load. Improper settings/adjustments of these control parameters could undermine the dynamic stability of the trunk, hence leading to low back injuries. The underlying stability mechanisms and associated control impairments during such dynamic movements remain elusive. Method Thirty-eight male volunteers (19 healthy, 19 NSLBP) enrolled in the current study. All participants performed repetitive trunk FE movements at high/low speeds, in symmetric/asymmetric directions, with/without a wearable loaded vest. Trunk instantaneous rotation angle was computed for each trial to be assessed in terms of local and orbital stability, using maximum finite-time Lyapunov exponents (LyEs) and Floquet multipliers (FMs), respectively. Results Both groups demonstrated equivalent competency in terms of trunk control and stability, suggesting functional adaptation strategies may be used by the NSLBP group. Wearing the loaded vest magnified the effects of trunk control impairment for the NSLBP group. The combined presence of high-speed and symmetrical FE movements was associated with least trunk local stability. Conclusion Nonlinear dynamic techniques, particularly LyE, are potentially effective for assessing trunk dynamic stability dysfunction for individuals with NSLBP during various activities. Application This work can be applied toward the development of quantitative personalized spinal evaluation tools with a wide range of potential occupational and clinical applications.

Not all movements are equal: Differences in the variability of trunk motor behavior between people with and without low back pain—A systematic review with descriptive synthesis

“…An expected finding was the variety in nomenclature and outcome measurements regarding variability [93]. For example, nine of the thirty articles did not use the term 'variability' in title and abstract [20,37,41,42,47,50,71,74,75] and in the eight studies of the subgroup magnitude EMG [39,49,54,60,63,69,73] six different outcome measures were used to express variability. The authors anticipated this when constructing this review and conducted an extensive search of the literature based on a comprehensive search strategy developed by an information specialist with expertise in the field.…”

“…Sample sizes for control groups varied from 6 to 80 with an average of 19 subjects. Twenty-one of the thirty-nine studies [14,[37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56] matched participants with and without LBP on the following factors: sex (n = 21), age (n = 14), body mass/Body Mass Index (n = 8), height (n = 5) and level of activity (n = 3).…”

Not all movements are equal: Differences in variability of trunk motor behavior between people with and without low back pain - A Systematic Review

“…Sample sizes for control groups varied from 6 to 80 with an average of 19 subjects. Twenty-one of the thirty-nine studies (22,(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59) matched participants with and without LBP on the following factors: sex (n=21), age (n=14), body mass/Body Mass Index (n=8), height (n=5) and level of activity (n=3).…”

“…One study (46) used the short form of the PCS. Twenty-eight studies (27,40,(42)(43)(44)(45)47,48,50,51,(53)(54)(55)(56)(57)(58)60,62,64,65,67,68,(73)(74)(75)(76)(77)(78) representing 518 of the 754 LBP participants (68.7%) did not measure any psychological construct. Ten studies (27,43,44,48,55,60,(75)(76)(77)(78) representing 199 of the 754 LBP participants (26.4%) did not report the use of any questionnaires to characterize the sample.…”

“…Eight type of trunk movement tasks were utilized to measure variability of trunk motor behavior. Treadmill walking and running tasks were most frequently used in ten studies (42,49,57,58,62,(66)(67)(68)76,77), trunk flexion-extension in eight studies (40,43,44,48,53,55,78,79) and lifting in six studies (22,27,46,52,71,74). Other tasks were overground walking in four studies (47,51,60,69), static postures in four studies (45,50,54,72), reaching in two studies (59,73), sit-to-stand in two studies (56,70), (maximally) voluntary contractions of trunk muscles in two studies (63,65) and a repositioning task in one study (64).…”