A Comprehensive Review of Pain Interference on Postural Control: From Experimental to Chronic Pain

Chronic low back pain and postural instability: interaction effects of pain severity, age, BMI, and disability

Objectives

This study aimed to (1) compare postural sway patterns between individuals with chronic low back pain (CLBP) and asymptomatic controls, (2) evaluate correlations between pain severity and postural stability variables, and (3) assess the interaction effects of age, BMI, pain severity, and disability on postural stability under eyes-open and eyes-closed conditions.

Methods

Postural stability (sway area, sway velocity, CoP displacement) was assessed in 88 CLBP patients and 88 controls using a stabilometric platform. Pain severity (VAS) and disability (ODI) were recorded alongside demographic data. Statistical analyses included t-tests, Pearson's correlations, and ANOVA to explore group differences, correlations, and interaction effects.

Results

Chronic low back pain patients exhibited significantly greater postural sway across all conditions, with larger sway area (16.80 ± 6.10 cm2 vs. 11.50 ± 4.10 cm2, p = 0.004) and higher sway velocity (4.10 ± 1.40 cm/s vs. 2.90 ± 1.00 cm/s, p = 0.009) under eyes-closed conditions. Pain severity correlated with sway velocity (r = 0.52, p = 0.003) and CoP displacement (r = 0.57, p = 0.002). Interaction effects indicated greater instability in older, obese individuals with severe pain and high disability.

Conclusion

Chronic low back pain is associated with impaired postural stability, influenced by pain severity, BMI, age, and disability. Targeted interventions addressing these factors are essential for improving balance and reducing fall risk.

Influence of cervical muscle strength and pain severity on functional balance and limits of stability in elderly individuals with chronic nonspecific neck pain: a cross-sectional study

BACKGROUND

Chronic nonspecific neck pain (CNSNP) is a common musculoskeletal disorder, particularly in the elderly, leading to reduced cervical muscle strength, impaired functional balance, and decreased postural stability. This study investigated the correlation between cervical muscle strength, functional balance, and limits of stability (LOS) in elderly individuals with CNSNP. Additionally, it assessed the moderating effect of pain severity on the relationship between cervical muscle strength and these balance outcomes.

METHODS

A prospective study included a total of 186 participants, including 93 with CNSNP and 93 asymptomatic individuals, were recruited. Cervical flexor and extensor muscle strength were assessed using an ergoFET hand-held dynamometer. Functional balance was measured using the Berg Balance Scale (BBS) and Timed Up and Go (TUG) test, while LOS were evaluated using the Iso-Free machine.

RESULTS

Individuals with CNSNP exhibited significantly lower cervical flexor strength (32.45 ± 5.67 N vs. 40.75 ± 5.20 N, p < 0.001) and extensor strength (28.30 ± 6.05 N vs. 36.90 ± 5.90 N, p < 0.001) compared to asymptomatic individuals. Functional balance was also poorer in the CNSNP group, with lower BBS scores (47.85 ± 4.20 vs. 53.65 ± 3.85, p < 0.001) and slower TUG times (11.30 ± 2.05 s vs. 8.45 ± 1.80 s, p < 0.001). Cervical muscle strength showed moderate to strong positive correlations with LOS (r = 0.56 to 0.62, p < 0.001) and BBS (r = 0.48 to 0.53, p < 0.001). Pain severity significantly moderated the relationship between cervical muscle strength and functional balance (β = 0.20, p = 0.045) as well as LOS (β = 0.22, p = 0.038), suggesting that higher pain levels diminish the positive effects of muscle strength on balance.

CONCLUSION

Cervical muscle strength plays a crucial role in maintaining functional balance and postural stability in elderly individuals with CNSNP. Pain severity moderates the relationship between cervical muscle strength and balance outcomes, emphasizing the importance of integrating muscle strengthening and pain management in rehabilitation programs for elderly individuals with CNSNP to optimize postural control and minimize fall risk.

Immediate Effects of Custom Foot Orthoses on Postural Balance and Pain in Obese Middle-Aged Women With Plantar Fasciitis

Given the prevalence of plantar fasciitis (PF) among middle-aged women, we investigated the immediate impact of custom foot orthoses (CFO) on pain and static and dynamic postural balance, addressing a critical gap in understanding the potential benefits of CFO in managing PF-related pain and postural instability. Nine middle-aged women with PF and obesity were evaluated for pain levels and center of pressure (CoP) values in bipedal, unipedal with a non-affected foot, and unipedal with an affected foot on the Timed Up and Go (TUG) test, while they were barefoot, wearing standard insoles (SI), and wearing CFO. We found that CFO significantly and immediately reduced pain (p < .01) improved CoP values (p < .01) in the unipedal stance with the affected foot, and enhanced TUG test scores (p < .001). The results demonstrated a significant (p < .01) improvement in CoParea values and TUG test scores with CFO, compared to SI. These findings underscore the immediate benefits of CFO in alleviating pain and improving postural balance in obese middle-aged women with PF, highlighting their potential as a valuable intervention.

Factors associated with pain-related functional interference in people with chronic low back pain enrolled in a physical exercise programme: the role of pain, sleep, and quality of life

OBJECTIVE

To identify the factors associated with the pain-related functional interference level in people with chronic low back pain.

DESIGN

Cross-sectional.

SUBJECTS/PATIENTS

Chronic low back pain patients.

METHODS

Sociodemographic data, pain intensity, pain-related functional interference, physical functioning and fitness, sleep quality, anxiety and depression, social support, and health-related quality of life were recorded. Descriptive and bivariate analyses were performed. A linear regression model was carried out to identify the factors associated with the pain-related functional interference level.

RESULTS

99 participants were involved (mean age: 54.37 SD: 12.44; women: 67.7%). 37.4%, 27.3%, and 35.4% were classified into low, moderate, and high pain-related functional interference level groups, respectively. Higher pain-related functional interference was associated with higher pain intensity (β: 0.724; p = 0.026), worse sleep quality (β: 0.077; p = 0.012), worse quality of life (physical (β: -0.539; p < 0.001) and mental (β: -0.289; p < 0.001), and lower consumption of weak opioids (β: -3.408; p = 0.037).

CONCLUSION

Beyond the pain experience and intensity among people with chronic low back pain, several biopsychosocial factors associated with this condition has been identified. Furthermore, higher pain intensity, worse sleep quality, worse quality of life, and weak opioids' consumption have been related to the pain-related functional interference of this population.

Association between central sensitization, pain sensitivity and balance control in patients with migraine

BACKGROUND

Balance alterations are prevalent among pain conditions, including migraine. The mechanisms explaining the association between pain and balance are unclear, as well as whether levels of pain sensitivity correlate with impaired balance. Our aim was therefore to investigate the association between balance, central sensitization symptoms and pain sensitivity in patients with migraine.

METHODS

This cross-sectional study included 50 patients and demographic, clinical information, central sensitization inventory (CSI) and pain catastrophizing (PCS) scores were obtained. Patients underwent a standardized protocol evaluating balance and pain thresholds for cold (CPT), heat (HPT), mechanical (MPT) and pressure (PPT) in trigeminal (V1) and extra-trigeminal (C6) dermatomes. Data were analysed using Person's correlation, linear regression models and contrasting the presence and absence of central sensitization symptoms through T-tests.

RESULTS

Mild-to-moderate correlations were observed between balance and MPT in V1 (r = -0.24, p = 0.046) and C6 (r = -0.41, p = 0.002), CPT in V1 (r = 0.31, p = 0.026), CSI scores (r = 0.27, p = 0.029) and migraine frequency (r = 0.25, p = 0.040). Balance was explained by CPT and MPT (R2 = 0.32, p = 0.001). The variance of CSI was explained by PCS scores and balance (R2 = 0.28, p = 0.001). Patients with symptoms of central sensitization presented an increased balance impairment (p = 0.044) and higher catastrophizing levels (p = 0.001) in contrast to patients without symptoms.

CONCLUSION

Balance impairment is associated with reduced pain thresholds and higher CSI scores. These results may help to elucidate the aetiology of balance alterations among chronic pain conditions.

SIGNIFICANCE

For the first time, it has been shown that balance alterations can reflect greater pain sensitivity and signs of central sensitization in patients with migraine. This opens up perspectives for future studies to understand the mechanisms and further factors associated with balance and pain sensitivity in migraine.

Alterations of postural control across the menstrual cycle - A systematic review

BACKGROUND

Postural control is a vital component of injury prevention and prediction and plays a critical role in sports performance. Its relationship with the phases of the menstrual cycle (MC) is not yet fully understood and requires further investigation.

RESEARCH QUESTION

Does postural control alter between high hormone and low hormone phases of the MC?

METHODS

Five electronic databases were searched by two reviewers between 30th November and 2nd December 2022. Included were studies that investigated the effects of the MC on static and dynamic postural control in naturally cycling (NC) women by comparing the early follicular phase (EFP) with at least one high hormone phase of the MC. Two reviewers conducted the literature search, selection of eligible studies, data extraction, methodological quality assessment utilizing a modified Downs and Black Checklist, GRADE guidelines and SIGN grading, and synthesis of results.

RESULTS

Nine studies examined the effects of the MC on static (n = 7), dynamic (n = 1), or both forms of postural control (n = 1) in 148 NC women. Included studies were of very low to moderate quality. Level of evidence was either 2 + (n = 1) or 2- (n = 8). Limited evidence of five very low-quality studies indicated decreased static postural control during the ovulatory phase of the MC, compared to the EFP. The decrements were present in balance tasks that altered sensory input of at least two sensory systems of postural control.

SIGNIFICANCE

This systematic review is the first compiling evidence on the effect of the MC on postural control. Evidence that the MC influences postural control is unclear. However, a trend towards decrements in postural control form EFP to OP was observed in balance tasks that eliminated or altered sensory input. Hence, compensatory strategies might be less effective during the OP.

The Observable Movement Quality scale for patients with low back pain (OMQ-LBP): validity and reliability in a primary care setting of physical therapy

BACKGROUND

The Observable Movement Quality scale for patients with low back pain (OMQ-LBP) is a newly developed measurement instrument for use in primary care settings of physical and exercise therapists to assess movement quality (MQ) of patients with low back pain (LBP).

OBJECTIVE

This study aims to determine validity, reliability and feasibility of the OMQ-LBP. The OMQ-LBP consists of a standardized movement circuit (performed twice) consisting of five daily activities problematic for LBP patients, which are scored with an 11-item observation list.

METHODS

Construct validity was determined by testing seven hypotheses on associations between constructs (n = 85 patients with LBP) and four hypotheses on known group differences (n = 85 patients with LBP and n = 63 healthy controls; n = 35 matched participant-patients having VAS-pain ≥ 20 mm during and/or after both circuits and healthy controls). Internal consistency was analyzed with Cronbach's alpha (n = 85 patients with LBP). For inter- and intra-rater reliability Intraclass Correlation Coefficient (ICC) values were examined (n = 14 therapists: seven primary care physical therapists and seven exercise therapists). Additionally, content validity and feasibility were determined using thematic analysis of a brief interview with participants, patients (n = 38) and therapists (n = 14).

RESULTS

After Bonferroni correction 2/7 associations between constructs and 2/4 significant group differences were confirmed. Cronbach's alpha was 0,79. The ICC-values of interrater reliability of the OMQ-LBP total score and the duration score were 0.56 and 0.99 and intra-rater reliability 0.82 and 0,93, respectively. Thematic analysis revealed five themes. Three themes elucidate that both patients and therapists perceived the content of the OMQ-LBP as valid. The fourth theme exhibits that OMQ-LBP provides a clear and unambiguous language for MQ in patients with LBP. Theme 5 depicts that the OMQ-LBP seems feasible, but video recording is time-consuming.

CONCLUSIONS

The OMQ-LBP is a promising standardized observational assessment of MQ during the five most problematic daily activities in patients with LBP. It is expected that uniform and objective description and evaluation of MQ add value to clinical reasoning and facilitate uniform communication with patients and colleagues.