Maintaining Lumbar Spine Stability: A Study of the Specific and Combined Effects of Abdominal Activation and Lumbosacral Orthosis on Lumbar Intrinsic Stiffness

The effect of abdominal bracing on respiration during a lifting task: a cross-sectional study

BACKGROUND

Abdominal bracing is a maneuver widely used by rehabilitation specialists and sports trainers to improve spinal stability. This study aimed to investigate how lifting tasks with and without abdominal bracing affect the respiratory function of the diaphragm.

METHODS

M-mode ultrasonographic assessment of diaphragmatic motion combined with spirometry was performed on 31 healthy adults. Participants were asked to breathe continuously whilst lifting a load with spontaneous abdominal muscle contraction (natural loaded breathing) and abdominal bracing (AB loaded breathing).

RESULTS

Pearson's correlations revealed strong correlations between ultrasonography and spirometry measures (p < 0.001) for all types of breathing: tidal breathing (r = 0.709, r2 = 0.503), natural loaded breathing (r = 0.731, r2 = 0.534) and AB loaded breathing (r = 0.795, r2 = 0.632). Using paired-samples t-tests, the natural loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p < 0.001) but not during expiration (p = .101). Spirometry demonstrated lower lung volumes (L) at the end of inspiration and expiration (p < 0.001), with no changes in total lung volume (p = 0.06). The AB loaded breathing ultrasonography revealed more caudal diaphragm positions during inspiration (p = 0.002) but not during expiration (p = 0.05). Spirometry demonstrated lower lung volumes at the end of inspiration (p < 0.001), expiration (p = 0.002), and total lung volumes (p = 0.019).

CONCLUSION

This study demonstrated that abdominal bracing performed during a lifting task reduces lung volume despite an increase in diaphragmatic motion. Diaphragm excursions strongly correlate with lung volumes even under postural loading.

TRIAL REGISTRATION

The study was prospectively registered on 8 April 2021 at ClinicalTrials.gov with identification number NCT04841109.

Effect of external lumbar supports on joint position sense, postural control, and postural adjustment: a systematic review

PURPOSE

To review the effects of external lumbar supports on various aspects of sensorimotor function including joint position sense (JPS), postural control, anticipatory postural adjustments (APAs), and compensatory postural adjustments (CPAs).

METHODS

A systematic literature search was performed in PubMed, EMBASE, Scopus, Ovid, Cochrane library, and Web of Science. Two reviewers selected studies which assessed the effect of lumbosacral orthosis or kinesio-tape on JPS, postural control or APAs/CPAs in subjects with and without low back pain (LBP). The methodological quality of included studies was assessed using a modified version of Downs and Black's checklist.

RESULTS

Findings demonstrated moderate effects of lumbosacral orthosis on specific aspects of sensorimotor control including JPS and to a lesser extent standing stability. These domains were not or minimally affected by application of kinesio-tape. Both orthosis and kinesio-tape had negligible effects on APAs and CPAs.

CONCLUSIONS

The positive effects of lumbar orthosis on JPS or postural control were mostly observed in conditions where sources of proprioceptive feedback are impaired (such as LBP) or absent (standing with eyes closed on an unstable surface). However, evidence does not prove significant positive effects for the application of kinesio-tape to improve sensorimotor control.IMPLICATIONS FOR REHABILITATIONWearing lumbar orthosis leads to an improvement in joint position sense.Postural stability seems to be affected to some extent by utilizing lumbar orthosis.Clinicians can administer orthosis to improve sensorimotor adaptation, especially in conditions with poor proprioception.Kinesio-tape had negligible effects on all domains of sensorimotor control.Improvement of sensorimotor function as a result of application of kinesio-tape is questionable.

Immediate Effect of Lumbosacral Orthosis and Abdominal Drawing-In Maneuver on Postural Control in Adults With Nonspecific Chronic Low Back Pain

OBJECTIVE

The purpose of this study was to examine the immediate effects of lumbosacral orthosis and the abdominal drawing-in maneuver on the trunk postural control of adults with chronic low back pain compared with asymptomatic controls during 1-legged and semi-tandem stances.

METHODS

An experimental and comparative study (cross-sectional design) was conducted in a laboratory setting. Twenty adults with chronic low back pain and 20 asymptomatic controls randomly performed 2 postural balance tasks over a force platform, considering 3 experimental conditions: (1) natural posture (baseline-control), (2) lumbosacral orthosis, and (3) abdominal drawing-in maneuver. Linear variables (mean amplitude, ellipse area, and sway velocity) derived from the center of pressure were computed, and 2-way analysis of variance (group × condition) for repeated measures were conducted.

RESULTS

No group × condition interactions (.139 ≤ P ≤.938) were detected in any center of pressure parameters. No condition effect was detected, but a group effect (P = .042) was observed for 1 center of pressure parameter. The chronic low back pain group presented with a lower mean anteroposterior center of pressure amplitude than asymptomatic controls (∆ = 0.31 ± 0.66 cm [95% confidence interval, 0.05-0.56], P = .019) during the semi-tandem stance balance task.

CONCLUSION

Neither lumbosacral orthosis nor the abdominal drawing-in maneuver showed immediate improvement in trunk postural control in any group. Thus, clinicians should not expect immediate benefits or improvements yielded by lumbosacral orthosis or the abdominal drawing-in maneuver when patients with chronic low back pain undergo these interventions.

The effect of extensible and non-extensible lumbosacral orthoses on anticipatory postural adjustments in participants with low back pain and healthy controls

BACKGROUND

Wearing a lumbosacral orthosis (LSO) is known to influence spine mechanics, but less is known about how LSOs affect motor control. Whether the use of a LSO can negatively affect motor control of the lumbar spine is still under debate.

OBJECTIVE

The current study examined the immediate effects of two flexible LSOs (extensible and non-extensible) on the anticipatory postural adjustments that prepare the spine for a predictable perturbation.

DESIGN

A comparative study using a repeated measures design in a laboratory setting.

METHODS

Healthy controls (n = 20) and participants with low back pain (n = 40) performed a rapid arm flexion/extension cycle with and without these LSOs. The latency between the activations of the shoulder and different back (iliocostalis lumborum) and abdominal (rectus abdominis, internal and external obliques) muscles, as measured with surface electromyography, was used as the outcome.

RESULTS

The effects, which were comparable between groups and between LSOs, were mixed, with some muscles showing significantly (p ˂ 0.05) earlier activation and others showing delayed activation with the use of a LSO, relative to the control condition. The corresponding effect sizes were low to average (Hedges's g range: 0.17-0.48).

CONCLUSIONS

These findings suggest a change in the motor program before task initiation, which might be generalizable to other activities of daily living or work. However, none of the effects were large, making it difficult to provide clear conclusions with regard to their clinical relevance. It remains to be tested whether these immediate adaptations in motor planning can induce long term detrimental effects to the control of lumbar stability.