Trunk rotation-related impairments in people with low back pain who participated in 2 different types of leisure activities: a secondary analysis

Disability reduction following a lumbar stabilization exercise program for low back pain: large vs. small improvement subgroup analyses of physical and psychological variables

BACKGROUND

Little is known about why patients with low back pain (LBP) respond differently to treatment, and more specifically, to a lumbar stabilization exercise program. As a first step toward answering this question, the present study evaluates how subgroups of patients who demonstrate large and small clinical improvements differ in terms of physical and psychological changes during treatment.

METHODS

Participants (n = 110) performed the exercise program (clinical sessions and home exercises) over eight weeks, with 100 retained at six-month follow-up. Physical measures (lumbar segmental instability, motor control impairments, range of motion, trunk muscle endurance and physical performance tests) were collected twice (baseline, end of treatment), while psychological measures (fear-avoidance beliefs, pain catastrophizing, psychological distress, illness perceptions, outcome expectations) were collected at four time points (baseline, mid-treatment, end of treatment, follow-up). The participants were divided into three subgroups (large, moderate and small clinical improvements) based on the change of perceived disability scores. ANOVA for repeated measure compared well-contrasted subgroups (large vs. small improvement) at different times to test for SUBGROUP × TIME interactions.

RESULTS

Statistically significant interactions were observed for several physical and psychological measures. In all these interactions, the large- and small-improvement subgroups were equivalent at baseline, but the large-improvement subgroup showed more improvements over time compared to the small-improvement subgroup. For psychological measures only (fear-avoidance beliefs, pain catastrophizing, illness perceptions), between-group differences reached moderate to strong effect sizes, at the end of treatment and follow-up.

CONCLUSIONS

The large-improvement subgroup showed more improvement than the small-improvement subgroup with regard to physical factors typically targeted by this specific exercise program as well as for psychological factors that are known to influence clinical outcomes.

Comparison of pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between people with and without nonspecific low back pain

BACKGROUND

Faults in postural alignment and movement of the pelvis are associated with non-specific low back pain. However, limited studies have investigated the differences in pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between subjects with and without non-specific low back pain.

METHODS

Thirty-one subjects with non-specific low back pain and 31 subjects without non-specific low back pain were examined. Angular measures of the pelvic rotation angle in the transverse plane were obtained in the supine position and during active straight leg raise using a Smart KEMA measurement system.

FINDING

The pelvic rotation angle in the transverse plane during active straight leg raise was significantly greater in subjects with non-specific low back pain than in healthy subjects (p < 0.05). However, the pelvic rotation angle in the transverse plane in the supine position and asymmetry index of the pelvic rotation angle during active straight leg raise were not significantly different between subjects with and those without non-specific low back pain.

INTERPRETATION

This indicates that a greater pelvic rotation angle in the transverse plane during active straight leg raise could be contributing factors to the development of a non-specific low back pain related to lumbopelvic instability.

A New Method of Evaluating the Symmetry of Movement Used to Assess the Gait of Patients after Unilateral Total Hip Replacement

Purpose

We propose a new concept of symmetry, the symmetry function, as a continuous function of the percentage of differences between sides of body movement and normalised throughout the whole range of motion. The method is used to assess the dynamical symmetry of gait of patients after unilateral total hip replacement (asymmetric group) and healthy people (symmetric group) and also to reveal discrepancies between normal and abnormal movement patterns.

Methods

The gait of twelve male patients (49.7 ± 2.8 y), six weeks after unilateral total hip replacement (uTHR), was analysed against the gait of thirteen healthy men (36.1 ± 3.1 y). The speed of healthy men was matched to the speed of the patients. Comparison of the affected limb in uTHR patients with the healthy limb of able-bodied men was carried out on the basis of the highest symmetry values in the sagittal plane.

Results

In uTHR patients, the symmetry function provides information on the symmetry of movements in the whole range of motion in contrast to symmetry indices which are calculated for selected parameters or peak values. Research revealed average asymmetric discrepancies for pelvic tilt up to 250% for the entire gait cycle with a peak of approx. 400% at the end of the loading response and terminal swing phases. Asymmetry of gait observed in other joints was below 200% of the mean range of motion.

Conclusions

Regions of the greatest asymmetry in pathological movements are usually different from the region of the greatest range of motion. Therefore, it is insufficient to measure symmetry only for selected regions during motion. The symmetry function is a simple method which can complement other robust methods in time series data evaluation and interpretation.

Can Biomechanics Research Lead to More Effective Treatment of Low Back Pain? A Point-Counterpoint Debate

SYNOPSIS

Although biomechanics plays a role in the development and perhaps the persistent or recurrent nature of low back pain (LBP), whether biomechanics alone can provide the basis for intervention is debated. Biomechanics, which refers to the mechanics of the body, including its neuromuscular control, has been studied extensively in LBP. But, can gains be made in understanding LBP by research focused on this component of biology in the multifactorial biopsychosocial problem of LBP? This commentary considers whether biomechanics research has the potential to advance treatment of LBP, and how likely it is that this research will lead to better treatment strategies. A point-counterpoint format is taken to present both sides of the argument. First, the challenges faced by an approach that considers biomechanics in isolation are presented. Next, we describe 3 models that place substantial emphasis on biomechanical factors. Finally, reactions to each point are presented as a foundation for further research and clinical practice to progress understanding of the place for biomechanics in guiding treatment of LBP. J Orthop Sports Phys Ther 2019;49(6):425-436. Epub 15 May 2019. doi:10.2519/jospt.2019.8825.

Convergence and Divergence of Exercise-Based Approaches That Incorporate Motor Control for the Management of Low Back Pain

Many approaches for low back pain (LBP) management focus on modifying motor control, which refers to motor, sensory, and central processes for control of posture and movement. A common assumption across approaches is that the way an individual loads the spine by typical postures, movements, and muscle activation strategies contributes to LBP symptom onset, persistence, and recovery. However, there are also divergent features from one approach to another. This commentary presents key principles of 4 clinical physical therapy approaches, including how each incorporates motor control in LBP management, the convergence and divergence of these approaches, and how they interface with medical LBP management. The approaches considered are movement system impairment syndromes of the lumbar spine, Mechanical Diagnosis and Therapy, motor control training, and the integrated systems model. These were selected to represent the diversity of applications, including approaches using motor control as a central or an adjunct feature, and approaches that are evidence based or evidence informed. This identification of areas of convergence and divergence of approaches is designed to clarify the key aspects of each approach and thereby serve as a guide for the clinician and to provide a platform for considering a hybrid approach tailored to the individual patient. J Orthop Sports Phys Ther 2019;49(6):437-452. Epub 15 May 2019. doi:10.2519/jospt.2019.8451.

Motor skill training in musculoskeletal pain: a case report in chronic low back pain

Purpose: Low back pain is a chronic condition that limits function. The chief reason individuals with low back pain seek care is difficulty performing functional activities. A novel approach to improving performance of painful and limited functional activities is motor skill training, defined as challenging practice of activities to learn or relearn a skill. The purpose of this report is to describe the design and application of a motor skill training intervention in a 26-year-old man with a 10-year history of low back pain. Methods: A motor skill training intervention was implemented to modify the altered alignment and movement patterns he used during the performance of his painful and limited activities. Results: The patient was seen for six visits in 12 weeks. The patient reported decreased pain and medication use, as well as improved function immediately, 3-, and 9-months post-intervention. Conclusion: Individuals with low back pain report limitation in ability to perform everyday functions and demonstrate altered patterns of movement and alignment during these activities. This case report describes an innovative motor skill training intervention that directly addresses the performance of functional activities and the application of motor learning principles. Implications for rehabilitation Low back pain is a chronic condition that limits function. The chief reason individuals with chronic low back pain seek care is difficulty performing everyday functional activities. Motor skill training is a novel approach that directly addresses the performance of painful and limited functional activities through challenging practice to improve performance and decrease pain.

Association between rotation-related impairments and activity type in people with and without low back pain

OBJECTIVE

To determine whether people with low back pain (LBP) who regularly participated in a rotation-related activity displayed more rotation-related impairments than people without LBP who did and did not participate in the activity.

DESIGN

Secondary analysis of data from a case-control study.

SETTING

Musculoskeletal analysis laboratory at an academic medical center.

PARTICIPANTS

A convenience sample of participants with LBP (n=55) who participated in a rotation-related sport, back-healthy controls (n=26) who participated in a rotation-related sport, and back-healthy controls (n=42) who did not participate in a rotation-related sport. Participants were matched based on age, sex, and activity level.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The total number of rotation-related impairments and asymmetrical rotation-related impairments identified during a standardized clinical examination.

RESULTS

Compared with the back-healthy controls who do not play a rotation-related sport group, both the LBP and back-healthy controls who play a rotation-related sport groups displayed significantly more (1) rotation-related impairments (LBP, P<.001; back-healthy controls who play a rotation-related sport, P=.015), (2) asymmetrical rotation-related impairments (LBP, P=.006; back-healthy controls who play a rotation-related sport, P=.020), and (3) rotation-related impairments with trunk movement tests (LBP, P=.002; back-healthy controls who play a rotation-related sport, P<.001). The LBP group had significantly more rotation-related impairments with extremity movement tests than both of the back-healthy groups (back-healthy controls who play a rotation-related sport, P=.011; back-healthy controls who do not play a rotation-related sport, P<.001).

CONCLUSIONS

The LBP and back-healthy controls who play a rotation-related sport groups demonstrated a similar number of total rotation-related impairments and asymmetrical rotation-related impairments, and these numbers were greater than those of the back-healthy controls who do not play a rotation-related sport group. Compared with people without LBP, people with LBP displayed more rotation-related impairments when moving an extremity. These findings suggest that impairments associated with extremity movements may be associated with having an LBP condition.

Individuals with non-specific low back pain in an active episode demonstrate temporally altered torque responses and direction-specific enhanced muscle activity following unexpected balance perturbations

Individuals with a history of non-specific low back pain (LBP) while in a quiescent pain period demonstrate altered automatic postural responses (APRs) characterized by reduced trunk torque contributions and increased co-activation of trunk musculature. However, it is unknown whether these changes preceded or resulted from pain. To further delineate the relationship between cyclic pain recurrence and APRs, we quantified postural responses following multi-directional support surface translations, in individuals with non-specific LBP, following an active pain episode. Sixteen subjects with and 16 without LBP stood on two force plates that were translated unexpectedly in 12 directions. Net joint torques of the ankles, knees (sagittal only), hips, and trunk, in the frontal and sagittal planes, were quantified and the activation of 12 muscles of the lower limb unilaterally and the dorsal and ventral trunk, bilaterally, were recorded using surface electromyography (EMG). Peaks and latencies to peak joint torques, rates of torque development (slopes), and integrated EMGs characterizing baseline and active muscle contributions were analyzed for group by perturbation direction (torques) and group by perturbation by epoch interaction (EMG) effects. In general, the LBP cohort demonstrated APRs that were of similar torque magnitude and rate but peaked earlier compared to individuals without LBP. Individuals with LBP also demonstrated increased muscle activity following perturbation directions in which the muscle was acting as a prime mover and reduced muscle activity in opposing directions, proximally and distally, with some proximal asymmetries. These altered postural responses may reflect increased muscle spindle sensitivity. Given that these motor alterations are demonstrated proximally and distally, they likely reflect the influence of central nervous system processing in this cohort.

Differences in lumbopelvic motion between people with and people without low back pain during two lower limb movement tests

BACKGROUND

Clinical data suggest that active limb movements may be associated with early lumbopelvic motion and increased symptoms in people with low back pain.

METHODS

Forty-one people without low back pain who did not play rotation-related sports and 50 people with low back pain who played rotation-related sports were examined. Angular measures of limb movement and lumbopelvic motion were calculated across time during active knee flexion and active hip lateral rotation in prone using a three-dimensional motion capture system. Timing of lumbopelvic motion during the limb movement tests was calculated as the difference in time between the initiation of limb movement and lumbopelvic motion normalized to limb movement time.

FINDINGS

During knee flexion and hip lateral rotation, people with low back pain demonstrated a greater maximal lumbopelvic rotation angle and earlier lumbopelvic rotation, compared to people without low back pain (P<0.05).

INTERPRETATION

The data suggest that people with low back pain who play rotation-related sports may move their lumbopelvic region to a greater extent and earlier during lower limb movements than people without low back pain. Because people perform many of their daily activities in early to midranges of joint motion the lumbopelvic region may move more frequently across the day in people with low back pain. The increased frequency may contribute to increased lumbar region tissue stress and potentially low back pain symptoms. Lower limb movements, therefore, may be important factors related to the development or persistence of low back pain.

The inter-tester reliability of physical therapists classifying low back pain problems based on the movement system impairment classification system

OBJECTIVE

The classification of patients with low back pain (LBP) may be important for improving clinical outcomes and research efficiency. The purpose of this study was to examine the inter-tester reliability of 2 trained physical therapists to classify patients with LBP by using the standardized Movement System Impairment (MSI) classification system. The 5 proposed MSI classifications are based on the most consistent patterns of movement and alignment observed throughout the examination that correlate with the patient's symptom behavior.

DESIGN

Test-retest to assess reliability

SETTING

Academic healthcare center outpatient facility

PARTICIPANTS

Thirty subjects (21 women and 9 men) with chronic, recurrent LBP (mean age 31.1 +/- 12.9 years) were examined independently by 2 experienced physical therapists.

METHODS

Training consisted of self-study of a procedure manual, a supervised practice of examination procedures and classification rules, and discussion. Subjects were examined independently by each therapist using a test-retest design. Each therapist assigned a LBP classification upon completion of the examination. Both therapists were blinded to the other therapist's findings.

MAIN OUTCOME MEASURES

Inter-tester reliability of therapists classifying the LBP problems was indexed by the percent agreement and kappa coefficient.

RESULTS

Overall percent agreement on the classification assigned was 83% with kappa = 0.75 (95% confidence interval = 0.51-0.99; P < .0001).

CONCLUSION

Inter-tester reliability of classification of patients with LBP when therapists use a standardized clinical examination based on the MSI classification system is substantial.

Symmetry of timing of hip and lumbopelvic rotation motion in 2 different subgroups of people with low back pain

OBJECTIVES

To examine whether lumbopelvic motion associated with a clinical test of active hip lateral rotation (HLR) systematically varied between people classified into 1 of 2 low back pain (LBP) subgroups: lumbar rotation (Rot) or lumbar rotation with extension (RotExt); and, specifically, to determine whether the timing of hip and lumbopelvic rotation with HLR would be more symmetric, right versus left, in people in the Rot subgroup compared with the RotExt subgroup.

DESIGN

Two-group, cross-sectional.

SETTING

A university-based movement science laboratory.

PARTICIPANTS

Subjects were 39 people (23 men, 16 women; mean age, 28.1+/-8.0 y) with chronic or recurrent LBP who regularly participated in a rotation-related sport and associated their LBP symptoms with participation.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Subjects participated in a standardized clinical examination to classify their LBP problem. A 3-dimensional movement system was used to capture kinematics of hip and lumbopelvic rotation during the test of active HLR. To examine timing of motion between the hip and lumbopelvic region, the difference in time between the start of hip and lumbopelvic rotation was calculated (startdiff). Symmetry of motion was indexed by the correlation (r) between right and left startdiff and the coefficient of determination (r2) for each LBP subgroup.

RESULTS

There were no significant differences between the 2 groups with regard to subject, LBP, activity, and range of motion variables (P range, >.05 for all comparisons). People in the Rot subgroup displayed significantly more symmetry of timing of hip and lumbopelvic rotation motion with active HLR than people in the RotExt subgroup (Rot subgroup: r=.94, r2=.88, P=.00; RotExt subgroup: r=.31, r2=.10, P=.12).

CONCLUSIONS

People in the Rot and RotExt subgroups displayed systematic differences in how they moved the hip and lumbopelvic region with the clinical test of active HLR. These findings are potentially important because such differences in movement patterns between subgroups of people with LBP suggest different contributing factors and may require different treatments to affect the movement patterns.