Differences in static balance and weight distribution between normal subjects and subjects with chronic unilateral low back pain

Effect of Whole-Body Vibration on Balance or Proprioception in Nonspecific Chronic Low Back Pain: A Systematic Review

Objective

This systematic review aimed to investigate the effect of whole-body vibration (WBV) on balance or proprioception for patients with nonspecific chronic low back pain (NSCLBP).

Methods

A comprehensive search was conducted using 5 databases-PubMed, Web of Science, Cochrane Library, Science Direct, and Physiotherapy Evidence Database-from inception to January 2022. Randomized clinical trials that examined the efficacy of WBV on balance or proprioception in patients with NSCLBP were incorporated. The methodological quality of each included study was assessed using the Physiotherapy Evidence Database scale.

Results

Our search strategy yielded 5309 articles, of which 7 published randomized clinical trials (313 patients) met the inclusion criteria. Three of the 4 included studies that investigated balance reported significant improvements after WBV, of which 2 were of high methodological quality. The remaining 3 studies investigating proprioception also showed significant improvements after WBV intervention.

Conclusion

Although some studies seem to provide promising results regarding the efficacy of WBV or WBV combined with exercise in improving balance and proprioception in patients with NSCLBP, at present, no definite conclusions can be drawn due to article heterogeneity and lack of clinical trials.

Association between functional disability with postural balance among patients with chronic low back pain

Introduction

Postural balance is impaired in patients with chronic low back pain (CLBP). In addition, the swaying velocity can be affected by low back pain (LBP) dysfunction. However, the extent to which the dysfunction affects postural balance in CLBP patients remains unclear. Therefore, this study aimed to investigate the effect of LBP-related disability on postural balance among CLBP patients and determine factors associated with postural balance impairments.

Methods

Participants with CLBP were recruited and instructed to complete the one-leg stance and Y-balance test. Moreover, they were divided into two subgroups (i.e., low and medium to high LBP-related disability groups) to compare the difference in postural balance based on the degree of LBP-related disability measured by the Roland Morris Disability Questionnaire. The relationships between postural balance and negative emotions as well as LBP characteristics were determined using the Spearman correlations.

Results

A total of 49 participants with low LBP-related disabilities and 33 participants with medium to high LBP-related disabilities participated in the study. Compared to the medium to high LBP-related disability group, patients in the low LBP-related disability group performed better in one-leg stance on the left leg (z = -2.081, p = 0.037). For Y-balance test, patients in the low LBP-related disability group also had greater normalized values of left leg reach in posteromedial (t = 2.108, p = 0.038) direction and composite score (t = 2.261, p = 0.026) and of right leg reach in posteromedial (t = 2.185, p = 0.032), and posterolateral (t = 2.137, p = 0.036) directions as well as composite score (t = 2.258, p = 0.027). Factors associated with postural balance impairments were also revealed, such as anxiety, depression, and fear avoidance belief.

Discussion

The greater the dysfunction degree, the worse the CLBP patient's postural balance impairment. Negative emotions could also be considered contributing factors for postural balance impairments.

Foot Posture Index Reference Values among Young Adults in Saudi Arabia and Their Association with Anthropometric Determinants, Balance, Functional Mobility, and Hypermobility

Background

The foot posture index (FPI) is a valid, reliable, and multidimensional method for determining foot posture in a wide range of clinical settings. To date, no normative data of healthy young adults in Saudi Arabia have been available for comparison and reference. Hence, this study is aimed at establishing the FPI reference values, gender, and side differences of FPI and their association with anthropometric determinants, balance, functional mobility, and hypermobility.

Methods

FPI was assessed in 581 (291 men and 290 women) healthy young adults aged 18–25 years. The FPI range was obtained for both feet as the sum of the scores (–2, –1, 0, 1, and 2) given to each criterion: (–1 to –12) supinated foot, (0 to +5) neutral foot, and (+6 to +12) pronated foot. The study furthermore assessed the balance using a near tandem balance test, functional mobility by stair ascent and descent test, and joint hypermobility via the Beighton scale.

Results

The average FPI score was 2.76 ± 5.23 for all subjects, 2.98 ± 5.02 for men and 2.55 ± 5.43 for women. Neutral foot posture was most frequent in this study (52.9%). A higher proportion of women had pronated (21.0%) and supinated (11.7%) feet than men which were 16.8% and 10.3%, respectively. This study also confirmed that side differences were found to be significant (p value < 0.001), whereas gender differences were significant only in the normal, pronated, and supinated foot groups.

Conclusion

The most common foot posture in both genders was ranged from neutral to slight pronation. We also found a correlation between balance with FPI in the supinated and hypersupinated foot groups, functional mobility with FPI of pronated and supinated foot groups, and joint hypermobility with FPI of the hyperpronated foot group.

Static Balance Modification during the Workday in Assembly Chain Workers with and without Current Low Back Pain

Background: Low back pain (LBP) is a common recurrent pathology among assembly chain workers. This population tends to spend most of the workday in a static standing posture and handling loads, with balance being essential for correct job performance. LBP is related to poorer postural control, so balance could be affected in this condition. Methods: The purpose of the present study is to analyze the deterioration of static balance generated by work activity in a prolonged standing position. We assess sway with a pressure platform at three moments of the workday (before, during, and after work), comparing the different balance parameters in 22 manufacturing plant workers with (17) and without (5) LBP. Results: In the pre-work capture, an independent t-test showed no significant differences between the pain and non-pain groups’ static balance parameters. Between the pre- and mid-workday captures, a two-way ANOVA with repeated measures showed a significant decrease in the medial-lateral center of pressure displacement with open eyes in workers with LBP. Conclusions: workers with low back pain do not show a greater deterioration in static balance than workers without pain during the workday.

Balance Ability in Low Back Pain Patients With Lumbosacral Radiculopathy Evaluated With Tetrax: A Matched Case-Control Study

Objective

To compare postural balance ability in patients with low back pain between groups with and without lumbosacral radiculopathy.

Methods

Patients who were referred for electromyography because of low back pain during the period from April 2017 through June 2018 were chosen as subjects. They were divided into groups with and without lumbosacral radiculopathy based on the results of electromyography. We used Tetrax (Sunlight Medical Ltd., Ramat Gan, Israel) to objectively evaluate postural balance ability, and to measure the fall risk, stability index, weight distribution index, and Fourier index.

Results

Patients in the lumbosacral radiculopathy group showed significantly higher fall risk (73.25 vs. 38.00; p<0.05), weight distribution index (8.57 vs. 5.00; p<0.05), and stability index (21.19 vs. 13.16; p<0.05) than those in the group without lumbosacral radiculopathy. The Fourier index at high-medium frequency was significantly increased in the lumbosacral radiculopathy group (8.27 vs. 5.56; p<0.05), whereas weight-bearing on the side of radiculopathy was significantly decreased.

Conclusion

Patients with lumbosacral radiculopathy have decreased postural balance compared with patients without this condition. Somatosensory disturbances in lumbosacral radiculopathy might cause postural balance impairment. Assessment and treatment plan not only for pain reduction but also for postural balance improvement should be considered in the management of patients with lumbosacral radiculopathy.

Efficacy of whole body vibration therapy on pain and functional ability in people with non-specific low back pain: a systematic review

BACKGROUND

Whole body vibration (WBV) is currently increasing in popularity as a treatment modality for musculoskeletal disorders and improving health-related quality of life. Recent research has shown that WBV can reduce low back pain and improve the functional abilities for patients, however, optimal frequency and duration of vibration for therapeutic use is unclear. This review was conducted to summarize and determine the efficacy of whole body vibration therapy on individuals with non-specific low back pain (NLBP) and evaluated methodological quality of the included studies.

METHODS

Online literature searches through the Web of Science, PubMed, Cochrane Library databases, PEDro, Ovid, EBSCO (Medline) and Scopus were conducted up to December 2019. Randomized controlled trials investigating the effect of WBV on pain intensity and/or functional ability in individuals with non-specific low back pain (NLBP) were included. Details of the sample characteristics, treatment of the comparison group, WBV parameters and outcome measures were recorded, and methodological quality appraised using the PEDro scale.

RESULTS

7 published RCTs (418 patients) were included in the systematic review. Due to heterogeneity in vibration parameters and prescriptions, and small number of studies, no meta-analysis was performed. Four out of the six included studies using pain as an outcome measure showed that WBV had a beneficial effect on pain compared with the control group, whereas only two trials were considered to be of high methodological quality. Among the six studies which measured functional ability, three studies with good quality reported significant between-group differences in favor of WBV.

CONCLUSIONS

There is limited evidence suggests that WBV is beneficial for NLBP when compared with other forms of interventions (stability training, classic physiotherapy, routine daily activity). Due to the small sample sizes and statistical heterogeneity, we still cannot draw conclusions that WBV is an effective intervention. Further high-quality studies are needed before clinical recommendations can be provided to support its use in a general population with NLBP and to explore the optimal treatment protocol.

TRIAL REGISTRATION

PROSPERO registration number: CRD42017074775.

Effects of Different Frequencies of Whole Body Vibration on Repositioning Error in Patients With Chronic Low Back Pain in Different Angles of Lumbar Flexion

OBJECTIVE

This study aimed to evaluate the effect of high and low frequency of whole body vibration (WBV) on repositioning error in 3 different angles of lumbar flexion in patients with chronic low back pain.

METHODS

Twenty-four participants with chronic low back pain, aged between 20 and 35 years, were included in this randomized crossover trial study. Participants were randomly assigned into 2 groups as follows: (1) low frequency/high frequency, and (2) high frequency/low frequency. Participants received high-frequency (50 Hz) and low-frequency (30 Hz) WBV in a semi-squat position for 5 minutes in 2 sessions, with 2 weeks of rest. Before and after the WBV, lumbar repositioning error in 30% and 60% of lumbar full flexion and neutral position with eyes closed when standing was evaluated using an electrogoniometer.

RESULTS

The repositioning error was decreased in neutral, 30%, and 60% of lumbar flexion after the low-frequency and high-frequency WBV. Post hoc testing revealed that the effect of angle was not significant in repositioning error changes between high-frequency and low-frequency WBV (P > .05). However, the effect of low-frequency WBV on the repositioning error was significantly higher compared with high-frequency WBV (P < .05).

CONCLUSION

Low-frequency WBV might induce more improvement in the accuracy of lumbopelvic repositioning compared with high-frequency WBV with the method of WBV used in this study.

Age- and low back pain-related differences in trunk muscle activation during one-legged stance balance task

BACKGROUND

Postural control declines with age and can be affected by low back pain. Poor balance has been reported in people with chronic low back pain (CLBP), which in turn could be explained by the changes in trunk muscle activation.

RESEARCH QUESTION

Are there differences between younger and older adults with and without chronic low back pain (CLBP) on trunk muscle activity during one-legged stance task?

METHODS

Twenty (20) with, and 20 subjects without nonspecific CLBP participated in the study. Each group was comprised of 10 younger (50% males; mean age: 31 years) and 10 older adults (50% males; mean age: 71 years). Subjects performed 3 × 30-second trials of one-legged stance, with eyes open, on a force platform, while surface electromyography (EMG) measurements were obtained bilaterally on the multifidus at L5, iliocostalis lumborum at L3, rectus abdominis and biceps femoris muscles.EMG amplitude analysis was processed by the Root Mean Square (250 ms window epochs) and normalized by the peak of activation during the balance tasks, to determine the muscular activity of each muscle.

RESULTS

Participants with CLBP presented 15% lower lumbar muscle activation (p <  0.05), and 23% higher co-activation (ratio between rectus adominis by multifidus) than participants without CLBP, regardless of age. Significant differences (p <  0.05) between older and young groups were observed only for lower lumbar muscles (mean 24% lower in older than younger adults) and rectus adominis muscles (mean 17% lower in older than younger adults).

SIGNIFICANCE

CLBP individuals have different trunk muscle activity than those without CLBP, and older adults exhibit lower trunk activation during one-legged stance balance task. The use of the EMG in evaluation of trunk neuromuscular function during one-legged stance may thus be a valuable tool when assessing balance in CLBP and older people.

Effects of trunk stabilization exercise on the local muscle activity and balance ability of normal subjects

[Purpose] The purpose of this study was to investigate the effects of trunk stabilization exercise on the transvers abdominalis (TA) and internal oblique (IO) muscle activity and balance ability of normal subjects. [Subjects and Methods] Forty healthy male subjects without orthopedic history of the lower extremity were selected for the present study. The experimental group received a hollowing exercise, curl-up and bridging exercise. The control group received a pelvic tilting exercise in the sitting position for the same period of time. [Results] Significant differences in the post-training gains in Balance index, TA, IO were observed between the experimental group and the control group. [Conclusion] The trunk stabilization exercise improved the balance ability and increased the activity of the TA and IO muscle.

The Effectiveness of Hollowing and Bracing Strategies With Lumbar Stabilization Exercise in Older Adult Women With Nonspecific Low Back Pain: A Quasi-Experimental Study on a Community-based Rehabilitation

OBJECTIVE

The purpose of this study was to explore the therapeutic effectiveness of hollowing lumbar stabilization exercise (HLSE) and bracing lumbar stabilization exercise (BLSE) for older adult women with nonspecific low back pain (NSLBP) in community welfare centers.

METHOD

A total of 38 older adult women with NSLBP were allocated to either the HLSE group (n = 17, 70.4 ± 1.7 years) or the BLSE group (n = 21, 66.8 ± 4.4 years). Both groups performed intervention for 12 consecutive weeks, 3 times per week. Each group performed 5 lumbar stabilization exercises, including side plank exercise, bridge exercise, 4-kneeling exercise, prone plank exercise, and prone back extension exercise with hollowing and bracing strategy, respectively. The baseline and post-test values of trunk strength, low back disability (Korean Oswestry Disability Index [K-ODI] and Korean Roland Morris Disability Questionnaire [K-RMDQ]), and static balance (1-leg standing test) were compared by using per-protocol analysis.

RESULTS

In trunk strength, the trunk flexor had significant difference (F = 11.10, P = .001) between groups and within groups of BLSE (t = -5.56, P = .001) and HLSE (t = -2.50, P = .024). Trunk back extensor of HLSE (t = -6.00, P = .001) and BLSE (t = -9.19, P = .001) only had significant within-group difference. However, in trunk side flexor, HLSE and BLSE had only significant difference between groups. In low back disability, K-ODI for HLSE (t = 4.50, P = .001) and BLSE (t = 4.60, P = .001) had significant within-group difference but no significant difference between groups (F = 0.28, P = .202). In K-RMDQ, HLSE only had significant within-group difference (t = 3.97, P = .001). In trunk muscle strength, the effect size of HLSE and BLSE groups for trunk flexor was HLSE -0.53 (medium) and BLSE -1.21 (large); trunk side flexor: HLSE 0.27 (small) and BLSE -0.24 (small); and trunk back extensor: HLSE 1.1 (large) and BLSE 2.00 (large), respectively. In low back disability, the effect size of both groups for K-ODI was HLSE 0.88 (large) and BLSE 1.05 (large), and K-RMDQ, HLSE 0.19 (small) and BLSE 0.40 (small), respectively.

CONCLUSION

Our findings suggest that HLSE and BLSE could be recommended for community settings to improve trunk strength and low back disability in older adult women with NSLBP. Especially, HLSE and BLSE could be recommended for elderly women with NSLBP who have lower back disability and weak trunk muscle strength, respectively.

Effects of Holding an External Load on the Standing Balance of Older and Younger Adults With and Without Chronic Low Back Pain

OBJECTIVE

The purpose of this study was to assess the effect of holding an external load on the standing balance of younger and older adults with and without chronic low back pain (CLBP).

METHODS

Twenty participants with and 20 without CLBP participated in the study. Each group contained 10 younger (50% men) and 10 older adults (50% men). Participants were instructed to look straight ahead while standing on a force platform during two 120-second trials with and without holding an external load (10% of body mass). The center of pressure area, mean velocity, and mean frequency in the anteroposterior and mediolateral directions were measured.

RESULTS

Older adults had worse standing balance than younger adults did (P < .001, d = 0.20). There were no significant balance differences between participants with and without CLBP within age groups during standing balance condition. However, holding the external load significantly increased postural instability for both age groups and CLBP status, with mean effect size across center of pressure variables of d = 0.82 for older participants without CLBP and d = 2.65 for younger participants without CLBP. These effects for people with CLBP were d = 1.65 for subgroup of older and d = 1.60 for subgroup of younger participants.

CONCLUSION

Holding an external load of 10% of body mass increased postural instability of both younger and older adults with and without CLBP.

People with chronic low back pain have poorer balance than controls in challenging tasks

PURPOSE

To compare the balance of individuals with and without chronic low back pain during five tasks.

METHOD

The participants were 20 volunteers, 10 with and 10 without nonspecific chronic low back pain, mean age 34 years, 50% females. The participants completed the following balance tasks on a force platform in random order: (1) two-legged stance with eyes open, (2) two-legged stance with eyes closed, (3) semi-tandem with eyes open, (4) semi-tandem with eyes closed and (5) one-legged stance with eyes open. The participants completed three 60-s trials of tasks 1-4, and three 30-s trials of task 5 with 30-s rests between trials. The center of pressure area, velocity and frequency in the antero-posterior and medio-lateral directions were computed during each task, and compared between groups and tasks.

RESULTS

Participants with chronic low back pain presented significantly larger center of pressure area and higher velocity than the healthy controls (p < 0.001). There were significant differences among tasks for all center of pressure variables (p < 0.001). Semi-tandem (tasks 3 and 4) and one-leg stance (task 5) were more sensitive to identify balance impairments in the chronic low back pain group than two-legged stance tasks 1 and 2 (effect size >1.37 vs. effect size <0.64). There were no significant interactions between groups and tasks.

CONCLUSIONS

Individuals with chronic low back pain presented poorer postural control using center of pressure measurements than the healthy controls, mainly during more challenging balance tasks such as semi-tandem and one-legged stance conditions. Implications for Rehabilitation People with chronic low back had poorer balance than those without it. Balance tasks need to be sensitive to capture impairments. Balance assessments during semi-tandem and one-legged stance were the most sensitive tasks to determine postural control deficit in people with chronic low back. Balance assessment should be included during rehabilitation programs for individuals with chronic low back pain for better clinical decision making related to balance re-training as necessary.

Normative Data for the NeuroCom Sensory Organization Test in US Military Special Operations Forces

CONTEXT

Postural stability is the ability to control the center of mass in relation to a person's base of support and can be affected by both musculoskeletal injury and traumatic brain injury. The NeuroCom Sensory Organization Test (SOT) can be used to objectively quantify impairments to postural stability. The ability of postural stability to predict injury and be used as an acute injury-evaluation tool makes it essential to the screening and rehabilitation process. To our knowledge, no published normative data for the SOT from a healthy, highly active population are available for use as a reference for clinical decision making.

OBJECTIVE

To present a normative database of SOT scores from a US Military Special Operations population that can be used for future comparison.

DESIGN

Cross-sectional study.

SETTING

Human performance research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 542 active military operators from Naval Special Warfare Combatant-Craft Crewmen (n = 149), Naval Special Warfare Command, Sea, Air, and Land (n = 101), US Army Special Operations Command (n = 171), and Air Force Special Operations Command (n = 121).

MAIN OUTCOME MEASURE(S)

Participants performed each of the 6 SOT conditions 3 times. Scores for each condition, total equilibrium composite score, and ratio scores for the somatosensory, visual, and vestibular systems were recorded.

RESULTS

Differences were present across all groups for SOT conditions 1 (P < .001), 2 (P = .001), 4 (P > .001), 5 (P > .001), and 6 (P = .001) and total equilibrium composite (P = .000), visual (P > .001), vestibular (P = .002), and preference (P > .001) NeuroCom scores.

CONCLUSIONS

Statistical differences were evident in the distribution of postural stability across US Special Operations Forces personnel. This normative database for postural stability, as assessed by the NeuroCom SOT, can provide context when clinicians assess a Special Operations Forces population or any other groups that maintain a high level of conditioning and training.

The effects on postural control and low back pain according to the types of orthoses in chronic low back pain patients

[Purpose] This study investigated how types of lumbosacral orthoses applied to patients with chronic lumbar pain affect postural control and low back pain. [Subjects and Methods] Ten subjects were randomly selected and allocated to each a group wearing soft lumbosacral orthoses and a group wearing rigid lumbosacral orthoses. They wore the lumbosacral orthoses for 4 weeks. Pain index and postural control were measured on the first day of wearing lumbosacral orthoses and 4 weeks later. Pain index was evaluated using a visual analogue scale, and postural control was measured using a Balance measurement system. The measurements examined included the overall balance index, anteroposterior balance index, and mediolateral balance index. [Results] There were statistically meaningful within-group differences in all variables, the visual analogue scale, overall balance index, anteroposterior balance index, and mediolateral balance index, in the group wearing soft lumbosacral orthoses. There were meaningful differences in visual analogue scale, overall balance index, and mediolateral balance index in the group wearing rigid lumbosacral orthoses. Furthermore, there was a meaningful difference in anteroposterior balance index between the group wearing soft lumbosacral orthoses and the group wearing rigid lumbosacral orthoses. [Conclusion] The results of the present study showed that wearing soft lumbosacral orthoses was more effective than wearing rigid lumbosacral orthoses.

The effects of exercising on an unstable surface on the gait and balance ability of normal adults

[Purpose] This study aimed to examine that therapeutic efficacy of an unstable surface on balance and gait ability in normal individuals. [Subjects and Methods] Forty subjects participated in the experiment and were randomly assigned to an experimental group of 20 subjects and a control group of 20 subjects. The experimental group performed balance exercise on an Aero-Step device (Aero-Step XL, TOGU, Prien-Bachham, Germany). The control group performed balance exercise on rigid ground. All subjects performed balance training 30 minutes a day, 5 days a week, for 4 weeks. After the intervention, balance measuring equipment (Good Balance, Metitur, Jyvaskyla, Finland) was used to quantitatively measure balance ability. [Results] Significant differences in post-training gains in the variables of static balance, dynamic balance, and velocity were observed between the experimental group and the control group. [Conclusion] Unstable surface training aimed at improving balance ability is considered to have a positive effect.

Effects of asymmetric sitting on spinal balance

[Purpose] To investigate the effects of two common asymmetric sitting positions on spinal balance. [Subjects and Methods] Thirty-seven healthy subjects in their twenties were enrolled and randomly divided into two groups. Asymmetric positions of resting the chin on a hand and crossing the legs were performed by each group for 1 hour. After 1 hour, the subjects lay in the supine position again and spinal imbalance was measured using a device. [Results] After 1 hour of resting with the chin on a hand, sagittal imbalance, coronal imbalance, pelvic obliquity and lordosis angle presented spinal imbalance worsening of 1 hour of crossing legs, sagittal imbalance, pelvic torsion showed in mainly learned spinal imbalance living. [Conclusion] Good posture could be an innate ability, however it through habits. So this study is meaningful from the perspective of the importance of good posture.

Surface electromyography studies in standing position confirm that ankle strategy remains disturbed even following successful treatment of patients with a history of sciatica

[Purpose] It is hypothesized that ankle strategy can be changed in patients with a history of sciatica. The aim of this study was to detect residual disturbances following successful treatment. [Subjects and Methods] In patients with a history of sciatica (N=11) and pseudo-sciatica (N=9), differences in muscle activity were recorded with bilateral surface polyelectromyography and stability measurements (center of foot pressure sway and center of spectrum) in normal standing and tandem positions. Results were compared with recordings in healthy people (N=9) to identify abnormalities in electromyographic and postural studies. [Results] Increased amplitude of electromyographic recordings from the gastrocnemius and extensor digiti muscles on the affected side was detected more in patients with a history of sciatica than pseudo-sciatica syndromes in tandem position. Fewer amplitude fluctuations were observed in both positions preferably in patients following sciatica. Changes in center of foot pressure sway and center of spectrum during balance platform studies were detected in normal standing position in this group of patients. No similar abnormalities in electromyographic and postural studies were detected in healthy people. [Conclusion] Sciatica and pseudo-sciatica evoke persistent disturbances in activity of muscles responsible for ankle strategy. Electromyography differentiates the two groups of patients better than postural studies.

The effect of lumbar stabilization exercises and thoracic mobilization and exercises on chronic low back pain patients

[Purpose] To investigate whether pain, balance, and stabilization of the lumbar region can be improved through thoracic mobilization in addition to lumbar stabilizaing exercises. [Subjects and Methods] This study recruited 36 subjects with chronic low back pain lasting more than 12 weeks. The subjects recruited for this study participated voluntarily, and provided their signed consent to participation. [Results] Improvement in balance was largest in the lumbar stabilization exercise group, followed by the thoracic mobilization and exercise group, and the traditional physical therapy group, in decreasing order of effect. [Conclusion] In conclusion, lumbar stabilization exercises combined with thoracic mobilization had greater effects on stabilization of the lumbar region pain relief, and improvement of the function of the patients with chronic low back pain.

The effects of gluteus muscle strengthening exercise and lumbar stabilization exercise on lumbar muscle strength and balance in chronic low back pain patients

[Purpose] The aim of this study was to examine the effects of exercise to strengthen the muscles of the hip together with lumbar segmental stabilization exercise on the lumbar disability index, lumbar muscle strength, and balance. [Subjects and Methods] This study randomly and equally assigned 40 participants who provided written consent to participate in this study to a lumbar segmental stabilization exercise plus exercise to strengthen the muscles of the gluteus group (SMG + LES group) and a lumbar segmental stabilization exercise group. [Results] Each evaluation item showed a statistically significant effect. [Conclusion] Clinical application of exercise in this study showed that lumbar segmental stabilization exercise plus exercise to strengthen the muscles of the gluteus resulted in a greater decrease in low back pain disability index and increase in lumbar muscle strength and balance ability than lumbar segmental stabilization exercise in chronic low back pain patients receiving the exercise treatments during the same period.

The effects of prone bridge exercise on trunk muscle thickness in chronic low back pain patients

[Purpose] This study aimed to investigate the effects of prone bridge exercise on trunk muscle thickness. [Subjects and Methods] Thirty-seven chronic low back pain patients participated in this study. Each participant was randomly assigned to one of three exercise groups, namely, a prone bridge exercise group, supine bridge exercise on a Swiss ball group, and supine bridge exercise group. The thicknesses of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) were measured using ultrasound. [Results] After eight weeks of training, the three groups showed significant increases in the thicknesses of the TrA, IO, and EO. Among the groups, TrA and IO showed significantly different muscle thicknesses. [Conclusion] The prone bridge exercise significantly affected the thicknesses of the TrA, IO, and EO unlike the supine bridge exercises. Based on the results of this study, the prone bridge exercise is a more effective method to improve trunk stability than conventional supine bridge exercises.

The effects of trunk stability exercise and a combined exercise program on pain, flexibility, and static balance in chronic low back pain patients

[Purpose] The aim of this study was to examine the effect of trunk stability exercise and combined exercise program on pain, flexibility, and static balance in chronic low back pain patients. [Subjects and Methods] Thirty persons diagnosed with chronic low back pain were divided into a trunk stability exercise group and a combined exercise group and then conducted exercise for six weeks. [Results] VAS and sway lengths decreased significantly in both groups. A comparison of sway lengths after the intervention between the two groups revealed that the trunk stability exercise group had a bigger decrease than the combined exercise group. [Conclusion] The results of this study indicated that trunk stability exercise would have bigger effect than combined exercise on the daily activities of chronic low back pain patients as it strengthens deep abdominal muscles and improves flexibility and balancing ability.

Low back pain and postural sway during quiet standing with and without sensory manipulation: a systematic review

A previous review concluded that postural sway is increased in patients with low back pain (LBP). However, more detailed analysis of the literature shows that postural deficit may be dependent on experimental conditions in which patients with LBP have been assessed. The research question to be answered in this review was: "Is there any difference in postural sway between subjects with and without LBP across several sensory manipulation conditions?". A literature search in Pubmed, Scopus, Embase and PsychInfo was performed followed by hand search and contact with authors. Studies investigating postural sway during bipedal stance without applying external forces in patients with specific and non-specific LBP compared to healthy controls were included. Twenty three articles fulfilled the eligibility criteria. Most studies reported an increased postural sway in LBP, or no effect of LBP on postural sway. In a minority of studies, a decreased sway was found in LBP patients. There were no systematic differences between studies finding an effect and those reporting no effect of LBP. The proportion of studies finding between-group differences did not increase with increased complexity of sensory manipulations. Potential factors that may have caused inconsistencies in the literature are discussed in this systematic review.

The influence of pain distribution on walking velocity and horizontal ground reaction forces in patients with low back pain

Objective. The primary purpose of this paper was to evaluate the influence of pain distribution on gait characteristics in subjects with low back problems (LBP) during walking at preferred and fastest speeds. Design. Cross-sectional, observational study. Setting. Gait analysis laboratory in a health professions university. Participants. A convenience age- and gender-matched sample of 20 subjects with back pain only (BPO), 20 with referred leg pain due to back problems (LGP), and 20 pain-free individuals (CON). Methods and Measures. Subjects completed standardized self-reports on pain and disability and were videotaped as they walked at their preferred and fastest speeds along a walkway embedded with a force plate. Temporal and spatial gait characteristics were measured at the midsection of the walkway, and peak medial, lateral, anterior, and posterior components of horizontal ground reaction forces (hGRFs) were measured during the stance phase. Results. Patients with leg pain had higher levels of pain intensity and affect compared to those with back pain only (t = 4.91, P < .001 and t = 5.80, P < 0.001, resp.) and walking had an analgesic effect in the BPO group. Gait velocity was highest in the control group followed by the BPO and LGP group and differed between groups at both walking speeds (F(2.57) = 13.62, P < .001 and F(2.57) = 9.09, P < .001, for preferred and fastest speed condition, resp.). When normalized against gait velocity, the LGP group generated significantly less lateral force at the fastest walking speed (P = .005) and significantly less posterior force at both walking speeds (P ≤ .01) compared to the control group. Conclusions. Pain intensity and distribution differentially influence gait velocity and hGRFs during gait. Those with referred leg pain tend to utilize significantly altered gait strategies that are more apparent at faster walking speeds.

Do individuals who develop transient low back pain exhibit different postural changes than non-pain developers during prolonged standing?

Previous literature has shown that individuals can develop transient low back pain (LBP) during a 2-h bout of unconstrained prolonged standing. The purpose of this study was to investigate the postural changes of individuals who develop LBP during standing (PD) and those who do not (NPD). Forty-one subjects (20 male, 21 female) participated in a 2-h prolonged standing occupational simulation and recorded their ratings of perceived LBP on a visual analog scale (VAS). Center of pressure changes (shifts, drifts, and fidgets) and body weight shifts were determined for each subject. All subjects showed an increase in the BW shift frequency and a decrease in average shift duration over the 2-h protocol. All NPD and female PD were consistent for many of the variables; however, male PD did not show similar patterns to the other groups, especially for anterior-posterior (AP) shift amplitude and total body weight asymmetry. Although gender differences between the pain groups were found, PD and NPD do not use different postural changes during unconstrained standing, showing that changes to postural control may be an "adaptive", rather than "causative" response to their LBP development. Future works should concentrate on bridging the literature seen in quiet standing before and after prolonged standing and the response of PD, as well as the effect of an exercise intervention on postural control, especially for male PD.

Vertical heterophoria and postural control in nonspecific chronic low back pain

The purpose of this study was to test postural control during quiet standing in nonspecific chronic low back pain (LBP) subjects with vertical heterophoria (VH) before and after cancellation of VH; also to compare with healthy subjects with, and without VH. Fourteen subjects with LBP took part in this study. The postural performance was measured through the center of pressure displacements with a force platform while the subjects fixated on a target placed at either 40 or 200 cm, before and after VH cancellation with an appropriate prism. Their postural performance was compared to that of 14 healthy subjects with VH and 12 without VH (i.e. vertical orthophoria) studied previously in similar conditions. For LBP subjects, cancellation of VH with a prism improved postural performance. With respect to control subjects (with or without VH), the variance of speed of the center of pressure was higher, suggesting more energy was needed to stabilize their posture in quiet upright stance. Similarly to controls, LBP subjects showed higher postural sway when they were looking at a target at a far distance than at a close distance. The most important finding is that LBP subjects with VH can improve their performance after prism-cancellation of their VH. We suggest that VH reflects mild conflict between sensory and motor inputs involved in postural control i.e. a non optimal integration of the various signals. This could affect the performance of postural control and perhaps lead to pain. Nonspecific chronic back pain may results from such prolonged conflict.

Differences in balance strategies between nonspecific chronic low back pain patients and healthy control subjects during unstable sitting

STUDY DESIGN

A 2-group experimental design.

OBJECTIVE

To investigate differences in postural control strategies of pelvis and trunk movement between nonspecific chronic low back pain (CLBP) patients and healthy control subjects using 3-dimensional motion analysis.

SUMMARY OF BACKGROUND DATA

Increased postural sway assessed by center of pressure displacements have been documented in patients with low back pain (LBP). The 3-dimensional movement strategies used by patients with LBP to keep their balance are not well documented.

METHODS

Nineteen CLBP patients and 20 control subjects were included based on detailed clinical criteria. Every subject was submitted to a postural control test in an unstable sitting position. A 3-dimensional motion analysis system, equipped with 7 infrared M1 cameras, was used to track 9 markers attached to the pelvis and trunk to estimate their angular displacement in the 3 cardinal planes.

RESULTS

The total angular deviation in all 3 directions of pelvis and trunk was higher in the CLBP group compared with the control group. In 4 of the 6 calculated differences, a significant higher deviation was found in the CLBP group (significant P-values between 0.013 and 0.047). Subjects of both groups mostly used rotation compared with lateral flexion and flexion/extension displacements of pelvis and trunk to adjust balance disturbance. The CLBP group showed a high correlation (Pearson: 0.912-0.981) between movement of pelvis and trunk, compared with the control group.

CONCLUSION

A higher postural sway and high correlation between pelvis and trunk displacements was found in the LBP group compared with healthy controls.

Postural control during prolonged standing in persons with chronic low back pain

Prolonged standing has been associated with the onset of low back pain symptoms in working populations. So far, it is unknown how individuals with chronic low back pain (CLBP) behave during prolonged unconstrained standing (PS). The aim of the present study was to analyze the control of posture by subjects with CLBP during PS in comparison to matched healthy adults. The center of pressure (COP) position of 12 CLBP subjects and 12 matched healthy controls was recorded in prolonged standing (30min) and quiet stance tasks (60s) on a force plate. The number and amplitude of COP patterns, the root mean square (RMS), speed, and frequency of COP sway were analyzed. Statistical analyses showed that CLBP subjects produced less postural changes in the antero-posterior direction with decreased postural sway during the prolonged standing task in comparison to the healthy group. Only CLBP subjects were influenced by the prolonged standing task, as demonstrated by their increased COP RMS, COP speed and COP frequency in the quiet standing trial after the prolonged standing task in comparison to the pre-PS trial. The present study provides additional evidence that individuals with CLBP might have altered sensory-motor function. Their inability to generate responses similar to those of healthy subjects during prolonged standing may contribute to CLBP persistence or an increase risk of recurrent back pain episodes. Moreover, quantification of postural changes during prolonged standing could be useful to identify CLBP subjects prone to postural control deficits.

Biomechanical effects of sitting with adjustable ischial and lumbar support on occupational low back pain: evaluation of sitting load and back muscle activity

Background

Compared to standing posture, sitting decreases lumbar lordosis, increases low back muscle activity, disc pressure, and pressure on the ischium, which are associated with occupational LBP. A sitting device that reduces spinal load and low back muscle activities may help increase sitting comfort and reduce LBP risk. The objective of this study is to investigate the biomechanical effect of sitting with a reduced ischial support and an enhanced lumbar support (Off-Loading) on load, interface pressure and muscle activities.

Methods

A laboratory test in low back pain (LBP) and asymptomatic subjects was designed to test the biomechanical effect of using the Off-Loading sitting posture. The load and interface pressure on seat and the backrest, and back muscle activities associated with usual and this Off-Loading posture were recorded and compared between the two postures.

Results

Compared with Normal (sitting upright with full support of the seat and flat backrest) posture, sitting in Off-Loading posture significantly shifted the center of the force and the peak pressure on the seat anteriorly towards the thighs. It also significantly decreased the contact area on the seat and increased that on the backrest. It decreased the lumbar muscle activities significantly. These effects are similar in individuals with and without LBP.

Conclusion

Sitting with reduced ischial support and enhanced lumbar support resulted in reduced sitting load on the lumbar spine and reduced the lumbar muscular activity, which may potentially reduce sitting-related LBP.

Multi-segment trunk kinematics during a loaded lifting task for elderly and young subjects

The trunk is frequently modelled as one fixed segment ignoring possible multi-segmental contributions during manual handling. This study compared segmental trunk motion in a young and older population during a lifting task. Twelve elderly and 19 young subjects repeatedly lifted a 5 kg box from bench to shelf under two stance conditions. Displacement and angular trunk segment kinematics were recorded with an electromagnetic tracker system and then analysed. The elderly subjects displayed significantly increased pelvic and trunk displacement and significantly reduced pelvic and lower thorax (T10-L1) range of motion in both stance conditions. Upper thorax (C7-T10) motion was at times greater than lumbar motion and opposite to the lower segments and was related to the task while the lower segments contributed to both equilibrium and task requirements. Decreased segmental trunk angular kinematics may contribute to increased displacement kinematics and place the elderly at increased risk of injury and falling. The pelvis, lumbar spine, low thorax (T10-L1), upper thorax (C7-10) contributed uniquely and synchronously to trunk (C7-S2) mechanics during a lifting task. Reduced angular kinematics of the pelvis and low thorax contributed to increased displacement kinematics and hence increased the risk of falling in the elderly compared to the young. Investigations of trunk mechanics should include multi-segment analysis.

Postural control measured as the center of pressure excursion in young female gymnasts with low back pain or lower extremity injury

Gymnasts are known to practice and compete although suffering from injuries and pain. Pain may change strategies for postural control. The primary aim of the present study was to investigate how center of pressure (COP) measurements are influenced by low back pain and lower extremity injury in top-level female gymnasts. A secondary aim was to study the reliability of these measurements using a test-retest design, and how this depends on the duration of the test. Fifty-seven top-level gymnasts were included in four groups: non-injured (NI, n=18), low back pain (LBP, n=11), lower extremity injury (LEI, n=17) and a multiple injury group (MI, n=11). COP excursion during quiet stance was measured on a force platform, during 120s: (1) hard surface/eyes open, (2) hard surface/eyes closed, (3) foam surface/eyes open and (4) foam surface/eyes closed. The COP excursion increased, for all groups, during the foam surface/eyes closed measurement compared to the other three tests. Furthermore, the LBP group showed a 49% (p=0.01) larger COP area compared to the LEI group in the foam surface/eyes closed condition. Measurements on foam surface were in general more reliable than tests on hard surface and tests with eyes closed were more reliable than tests with eyes open. Tests during 120s were in most cases more reliable than tests during 60s. In conclusion the COP excursion is influenced by injury location. Quiet stance measurements on foam surface with eyes closed seems to be reliable and sensitive in young female gymnasts.

Impaired postural stability in patients with cervical myelopathy: evaluation by computerized static stabilometry

STUDY DESIGN

A prospective clinical study.

OBJECTIVE

To quantitatively evaluate impairment of postural stability in patients with cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Proprioceptive sensation plays an important role in coordinated movement of the lower extremities and postural stability. Nevertheless, although disturbance of proprioceptive information will have an influence on the maintenance of postural stability, there have been few studies dealing with deterioration of postural stability in patients with cervical myelopathy.

METHODS

We investigated 52 cervical myelopathy patients who could stand without support and compared the results with those of 29 age-matched healthy volunteers. Postural stability was examined using a stabilometer. In the stabilometer, sway of gravity center was measured at upright position with eyes closed for 30 seconds. We used 2 parameters for evaluation: environmental area (EA), which measures degree of sway of the gravity center, and locus length per environmental area (L/EA), which measures fine control of standing posture by proprioceptive reflexes.

RESULTS

The mean EA of the patient group was 13.9, whereas that of the control group was 2.74, revealing significantly larger postural instability in the patient group compared to the control group. The L/EA of the patient group was significantly worse than the control group. It was also shown that postural instability was significantly larger in the myelopathy patients with the severe clinical symptoms.

CONCLUSION

The results of the present study demonstrate impairment of postural stability in patients with cervical myelopathy. The stabilometer can objectively evaluate the postural stability, which may reflect the function of the dorsal columns and the corticospinal tracts. Thus, stabilometry is a useful method for measuring a part of proprioceptive function and for objective assessment of the lower limb function of cervical myelopathy.

Is balance different in women with and without stress urinary incontinence?

AIMS

This study investigated whether there are differences in center of pressure (COP) displacement, trunk motion, and trunk muscle activity in women with and without stress urinary incontinence (SUI) during static balance tasks when the bladder is empty and moderately full.

METHODS

Subjects stood on a force plate during six static balance conditions: eyes open, eyes closed, standing on foam with eyes open, standing on foam with eyes closed, tandem stance, and standing on a short base. Electromyographic activity (EMG) of the pelvic floor (PF), abdominal, and erector spinae muscles were recorded using surface electrodes. Motion of the lumbar spine, pelvis, and hips was measured with four inclinometers. Trials were performed with the bladder empty, and when the subject reported a sensation of moderate bladder fullness after drinking 250-1,000 ml of water.

RESULTS

Women with SUI had greater COP displacement (range and root mean square), and increased trunk muscle EMG during static balance tests compared to continent women. When tasks were performed with the bladder moderately full, COP displacement and abdominal muscle EMG were increased in both groups.

CONCLUSIONS

This study demonstrates that women with SUI have decreased balance ability compared to continent women. Increased activity of the PF and trunk muscles in women with SUI may impair balance as a result of a reduced contribution of trunk movement to postural correction or compromised proprioceptive acuity. As compromised balance has been linked to falls risk, further research into balance deficits and falls prevalence in this population is warranted.

Failure to use movement in postural strategies leads to increased spinal displacement in low back pain

STUDY DESIGN

Lumbar and hip movements, before and in response to rapid bilateral arm flexion, were evaluated in 10 people with recurrent low back pain (LBP) and 10 matched control subjects when standing on a flat surface or short base.

OBJECTIVE

To evaluate the preparatory movement and resultant displacement of the lumbopelvic region associated with internal perturbation in people with or without LBP.

SUMMARY OF BACKGROUND DATA

Strategies to control the trunk involve movement. Small spinal movements (preparatory movement), opposite to the direction of reactive moments, precede voluntary arm movements in healthy individuals. However, people with LBP often use less spinal movement. We hypothesized that the tendency to reduce spinal motion in LBP may be associated with decreased preparatory motion, and this may counter intuitively lead to increased displacement of the trunk in response to arm movements.

METHODS

Movements at the lumbopelvic region before and in response to rapid bilateral arm flexion were examined using electromagnetic motion sensors when subjects were standing on a flat surface or short base.

RESULTS

In control subjects, preparatory extension of the lumbar spine preceded a resultant flexion of the region in 88% of trials on the flat surface. People with LBP used preparatory extension less frequently (69%, P = 0.027). Consequently, the spinal displacement (resultant flexion) induced by shoulder flexion was significantly greater in the LBP group (3.2 degrees +/- 1.8 degrees) than controls (1.8 degrees +/- 1.6 degrees, P = 0.004). There was a significant correlation (r = 0.47) between preparatory and resultant movement of the lumbar spine in the LBP group, which indicates that subjects with reduced preparatory extension were more likely to have a greater resultant displacement.

CONCLUSION

These data suggest that spinal movement is different in people with LBP, and reduced spinal movement in advance of predictable perturbation may be associated with compromised quality of trunk control.

Reproducibility of postural control measurement during unstable sitting in low back pain patients

Background

Postural control tests like standing and sitting stabilometry are widely used to evaluate neuromuscular control related to trunk balance in low back pain patients. Chronic low back pain patients have lesser postural control compared to healthy subjects. Few studies have assessed the reproducibility of the centre of pressure deviations and to our knowledge no studies have investigated the reproducibility of three-dimensional kinematics of postural control tests in a low back pain population. Therefore the aim of this study was to assess the test-retest reproducibility of a seated postural control test in low back pain patients.

Methods

Postural control in low back pain patients was registered by a three dimensional motion analysis system combined with a force plate. Sixteen chronic low back pain patients having complaints for at least six months, were included based on specific clinical criteria. Every subject performed 4 postural control tests. Every test was repeated 4 times and lasted 40 seconds. The force plate registered the deviations of the centre of pressure. A Vicon-612-datastation, equipped with 7 infra-red M1 camera's, was used to track 13 markers attached to the torso and pelvis in order to estimate their angular displacement in the 3 cardinal planes.

Results

All Intraclass Correlation Coefficients (ICC) calculated for the force plate variables did not exceed 0.73 (ranging between 0.11 and 0.73). As for the torso, ICC's of the mean flexion-extension and rotation angles ranged from 0.65 to 0.93 and of the mean lateral flexion angle from 0.50 to 0.67. For the pelvis the ICC of the mean flexion-extension angle varied between 0.66 and 0.83, the mean lateral flexion angle between 0.16 and 0.81 and the mean rotation angle between 0.40 and 0.62.

Consecutive data suggest that the low test-retest reproducibility is probably due to a learning effect.

Conclusion

The test-retest reproducibility of these postural control tests in an unstable sitting position can globally be considered as rather moderate. In order to improve the test-retest reproducibility, a learning period may be advisable at the beginning of the test.

Effects of chronic low back pain on trunk coordination and back muscle activity during walking: changes in motor control

Low back pain (LBP) is often accompanied by changes in gait, such as a decreased (preferred) walking velocity. Previous studies have shown that LBP diminishes the normal velocity-induced transverse counter-rotation between thorax and pelvis, and that it globally affects mean erector spinae (ES) activity. The exact nature and causation of these effects, however, are not well understood. The aim of the present study was to examine in detail the effect of walking velocity on global trunk coordination and ES activity as well as their variability to gain further insights into the effects of non-specific LBP on gait. The study included 19 individuals with non-specific LBP and 14 healthy controls. Gait kinematics and ES activity were recorded during treadmill walking at (1) a self-selected (comfortable) velocity, and (2) sequentially increased velocities from 1.4 up to maximally 7.0 km/h. Pain intensity, fear of movement and disability were measured before the experiment. The angular movements of thorax, lumbar and pelvis were recorded in three dimensions. ES activity was recorded with pairs of surface electrodes. Trunk-pelvis coordination and mean amplitude of ES activity were analyzed. In addition, invariant and variant properties of trunk kinematics and ES activity were studied using principal component analysis (PCA). Comfortable walking velocity was significantly lower in the LBP participants. In the transverse plane, the normal velocity-induced change in pelvis-thorax coordination from more in-phase to more antiphase was diminished in the LBP participants, while lumbar and pelvis rotations were more in-phase compared to the control group. In the frontal plane, intersegmental timing was more variable in the LBP than in the control participants, with additional irregular movements of the thorax. Rotational amplitudes were not significantly different between the LBP and control participants. In the LBP participants, the pattern of ES activity was affected in terms of increased (residual) variability, timing deficits, amplitude modifications and frequency changes. The gait of the LBP participants was characterized by a more rigid and less variable kinematic coordination in the transverse plane, and a less tight and more variable coordination in the frontal plane, accompanied by poorly coordinated activity of the lumbar ES. Pain intensity, fear of movement and disability were all unrelated to the observed changes in coordination, suggesting that the observed changes in trunk coordination and ES activity were a direct consequence of LBP per se. Clinically, the results imply that conservative therapy should consider gait training as well as exercises aimed at improving both intersegmental and muscle coordination.

Hip strategy for balance control in quiet standing is reduced in people with low back pain

STUDY DESIGN

Quiet stance on supporting bases with different lengths and with different visual inputs were tested in 24 study participants with chronic low back pain (LBP) and 24 matched control subjects.

OBJECTIVES

To evaluate postural adjustment strategies and visual dependence associated with LBP.

SUMMARY OF BACKGROUND DATA

Various studies have identified balance impairments in patients with chronic LBP, with many possible causes suggested. Recent evidence indicates that study participants with LBP have impaired trunk muscle control, which may compromise the control of trunk and hip movement during postural adjustments (e.g., hip strategy). As balance on a short base emphasizes the utilization of the hip strategy for balance control, we hypothesized that patients with LBP might have difficulties standing on short bases.

METHODS

Subjects stood on either flat surface or short base with different visual inputs. A task was counted as successful if balance was maintained for 70 seconds during bilateral stance and 30 seconds during unilateral stance. The number of successful tasks, horizontal shear force, and center-of-pressure motion were evaluated.

RESULTS

The hip strategy was reduced with increased visual dependence in study participants with LBP. The failure rate was more than 4 times that of the controls in the bilateral standing task on short base with eyes closed. Analysis of center-of-pressure motion also showed that they have inability to initiate and control a hip strategy.

CONCLUSIONS

The inability to control a hip strategy indicates a deficit of postural control and is hypothesized to result from altered muscle control and proprioceptive impairment.

Development of kinematics tests for the evaluation of lumbar proprioception and equilibration

OBJECTIVE

This study aimed at developing lumbar repositioning and seated equilibration tests.

DESIGN

3D-electrogoniometric study of trunk repositioning and equilibration in seated position.

BACKGROUND

Postural equilibrium and lumbar proprioception alterations have been shown in patients with low-back pain.

METHODS

In 21 healthy volunteers, pure flexion and flexion+rotation repositioning error was measured using 3D-electrogoniometry. Lumbar kinematics was analysed (time and frequency domain) during antero-posterior and lateral equilibration tests in seated position. Reproducibility and stability of the protocol were evaluated.

RESULTS

Reproducibility and stability were good. Pure flexion repositioning error was similar to previous reports. For flexion+rotation tests, repositioning error was 3 degrees for flexion and 1 degrees for rotation. Amplitude, imbalance time and power spectrum were significantly larger in lateral than in antero-posterior equilibration tests.

CONCLUSIONS

The feasibility of kinematic analysis of lumbar repositioning and equilibration was shown. Repositioning error values were in agreement with previous studies. New tests and parameters were proposed. Lateral equilibration tests appeared more demanding than antero-posterior tests.

RELEVANCE

In patients with low-back pain, lumbar repositioning and equilibration tests may be of use to define rehabilitation strategies and to evaluate treatment outcome.

Treatment of chronic lower back pain with lumbar extension and whole-body vibration exercise: a randomized controlled trial

STUDY DESIGN

A randomized controlled trial with a 6-month follow-up period was conducted.

OBJECTIVE

To compare lumbar extension exercise and whole-body vibration exercise for chronic lower back pain.

SUMMARY OF BACKGROUND DATA

Chronic lower back pain involves muscular as well as connective and neural systems. Different types of physiotherapy are applied for its treatment. Industrial vibration is regarded as a risk factor. Recently, vibration exercise has been developed as a new type of physiotherapy. It is thought to activate muscles via reflexes.

METHODS

In this study, 60 patients with chronic lower back pain devoid of "specific" spine diseases, who had a mean age of 51.7 years and a pain history of 13.1 years, practiced either isodynamic lumbar extension or vibration exercise for 3 months. Outcome measures were lumbar extension torque, pain sensation (visual analog scale), and pain-related disability (pain disability index).

RESULTS

A significant and comparable reduction in pain sensation and pain-related disability was observed in both groups. Lumbar extension torque increased significantly in the vibration exercise group (30.1 Nm/kg), but significantly more in the lumbar extension group (+59.2 Nm/kg; SEM 10.2; P < 0.05). No correlation was found between gain in lumbar torque and pain relief or pain-related disability (P > 0.2).

CONCLUSIONS

The current data indicate that poor lumbar muscle force probably is not the exclusive cause of chronic lower back pain. Different types of exercise therapy tend to yield comparable results. Interestingly, well-controlled vibration may be the cure rather than the cause of lower back pain.

Intra-operator and inter-operator reliability of surface electromyography in the clinical evaluation of back muscles

As a prerequisite to the use of a test battery based on electromyographic (EMG) analysis of the paraspinal muscles for identifying and remedying back muscle dysfunction, the intra- and inter-operator reliability was assessed. Fifteen volunteers underwent EMG tests on three occasions. The test subjects were asked to perform 22 exercises, subdivided into four categories: coordination, stabilization, balance and strength exercises. The time interval between the tests was one week. The myoelectric signals of the multifidus (MF) and iliocostalis lumborum pars thoracis (ICLT) were analysed with regard to amplitude (averaged EMG) and frequency (zero cross rate). The results indicated that the reliability was better for the MF than for the ICLT, and also for exercises at higher loads (strength exercises). In the intra-operator condition, the reproducibility of the averaged EMG was good (ICC>0.75), except for the balance exercises (ICC = 0.40-0.74). In general, the averaged EMG in the inter-operator condition and the zero cross rate in both the intra- and inter-operator conditions are less or poorly reliable. These results demonstrate that when back muscle function is evaluated during coordination, stabilization and strength exercises, only the averaged EMG parameter has acceptable reproducibility over time when assessed by the same operator.