Clinical characteristics of geriatric patients with non-specific chronic low back pain

Targeted vibratory therapy as a treatment for proprioceptive dysfunction: Clinical trial in older patients with chronic low back pain

INTRODUCTION

Proprioceptive function declines with age, leading to falls, pain, and difficulties in performing activities of daily living among older adults. Although individuals with low back pain (LBP) exhibit decreased lumbosacral proprioception in various postures, the mechanism by which reduced proprioceptive function causes LBP remains uncertain. Vibratory stimulation may enhance proprioceptive function; however, its efficacy in treating LBP has not been investigated. Thus, we investigated the feasibility of improving proprioceptive function and its effect on alleviating chronic LBP in older patients through targeted vibratory therapy (TVT) administration.

METHODS

This single arm designed trial included older patients aged >65 years with non-specific chronic LBP. TVT involved applying vibratory stimulation, matching the frequency of dysfunctional receptors, for 1 min daily over 14 days to activate proprioceptors; patients performed TVT three times daily at home. In cases of reduced proprioceptive function at multiple sites, TVT was aimed at the lowest frequency band value. LBP and proprioceptive function were evaluated at 2 weeks after TVT and at 2 weeks after the end of TVT in patients with declined proprioception in the trunk or lower extremities.

RESULTS

Overall, 56 patients with chronic LBP were enrolled; 32 patients were recruited for treatment based on a proprioceptive dysfunction diagnosis and 24 patients were recruited with a normal diagnosis with no significant differences observed between the two sets of patients in sarcopenia-related factors and clinical proprioception-related characteristics. No patient had any adverse events. Two weeks after TVT, the numerical pain rating scale score improved to <3 points in 78.1% of patients, with 73.1% of patients achieving a score of ≤ 3 points. Proprioceptive function improved in 81.3% of cases, and engagement in activities of daily living improved significantly.

CONCLUSIONS

TVT demonstrated efficacy in improving proprioception and alleviating LBP in older patients with impaired proprioceptive function without affecting non-targeted proprioceptors.

Proprioceptive reliance on trunk muscles for maintaining postural stability decreases in older patients with sagittal imbalance

BACKGROUND

Control of postural adjustments requires tight regulation of the spinal alignments. Sagittal imbalance may cause balance impairment and proprioceptive decline in older adults. However, the evidence on the proprioceptive mechanisms is limited, although it is known that poor proprioceptive inputs may induce spinal deformities. Thus, this study aimed to measure proprioceptive control quantifiers in older adults with sagittal imbalance to clarify the characteristic postural adjustments during proprioceptive inputs.

RESEARCH QUESTION

What are the specific proprioceptive postural adjustments required to maintain balance in older adult patients with lumbar spondylosis?

METHODS

This was a cross-sectional, observational study. The participants were classified according to the sagittal vertical axis (SVA) lengths with 50 mm as the cut-off value. The pressure displacement center was determined in 36 patients without sagittal imbalance and 68 patients with sagittal imbalance during an upright stance on a balance board with eyes closed. Vibratory stimulations of 27-272 Hz were applied to the gastrocnemius (GS) and lumbar multifidus (LM) muscles to measure the relative contributions and center of pressures of different relative proprioceptive weighting ratios (RPWs) used on postural adjustments.

RESULTS

The RPWs of older adults with sagittal imbalance were higher than that in those without sagittal imbalance (56-100 Hz; p = 0.013). Logistic regression analysis showed that older patients with sagittal imbalance had a significant ankle proprioception control of advantage (odds ratio: 1.1, 95% confidence interval: 1.01-1.1, p = 0.012).

SIGNIFICANCE

In older patients with sagittal imbalance, the reliance on hip strategy during balance control (RPW 56-100 Hz) decreases. A quantitative assessment of postural stability during proprioceptive inputs is crucial to identify dependence on proprioception signals, including postural strategy, in older patients with sagittal imbalance. Interventions to improve proprioception can improve the postural stability and strategy of older patients with sagittal imbalance.

Relationships Between Skeletal Muscle Mass, Lumbar Lordosis, and Chronic Low Back Pain in the Elderly

OBJECTIVE

Loss of skeletal muscle mass is known to be associated with multiple morbidities. However, there is a dearth of reports on its association with lumbar lordosis and musculoskeletal pain. The aim of this study was to delineate the cross-sectional relationship between loss of skeletal muscle mass, lumbar lordosis, and chronic low back pain (CLBP).

METHODS

A total of 721 medical records were reviewed, and data from 165 older subjects (over 65 years old; 81 men and 84 women) were retrospectively analyzed. Subjects were categorized into either the CLBP group (back pain for more than 6 months; 35 men and 36 women) or the control group (46 men and 48 women). The modified skeletal muscle mass index (MSMI, appendicular skeletal muscle mass [kg]/weight [kg] × 100), assessed by bioelectrical impedance analysis, and lumbar lordotic angle (LLA) were measured and compared between the CLBP group and the control group. The correlation between MSMI and LLA was investigated.

RESULTS

The LLA of men and women in the CLBP group was significantly lower than that of the control group (p < 0.05). The MSMI was decreased in the CLBP group compared to the control group (p < 0.05). For both sexes, positive correlations were observed between the MSMI and LLA.

CONCLUSION

A close cross-sectional relationship was observed between MSMI, LLA, and CLBP. This suggests a potential interaction between the reduction in skeletal muscle mass and altered lumbar spine sagittal alignment, which could lead to CLBP.

Skeletal Muscle and Fat Mass Reflect Chronic Pain in Older Adult

Objectives: The prevalence of chronic pain increases with age. It has been reported that chronic pain is associated with sarcopenia and obesity. Age-related skeletal muscle loss and fat gain are known to occur due to chronic inflammation. The aim of this study was to analyze how skeletal muscle and fat, caused by chronic inflammation due to aging, regulate the development of geriatric chronic pain. Methods: The results of skeletal muscle and fat mass, 412 participants aged ≥65 years with non-specific chronic pain lasting ≥6 months, including low back, neck, and knee pain, was compared with the control without chronic pain. Body composition threshold regulating chronic pain was calculated. Results: A significantly lower skeletal muscle mass index and higher body fat percentage were observed in patients with chronic pain than that in the control. The muscle fat ratio (MFR) was significantly lower in the chronic pain group than in the control group. When the MFR threshold related to chronic pain was calculated by sex, it was 2.984 for men and 1.867 for women. Conclusions: Evaluation of the body composition of elderly patients with non-specific chronic pain revealed that the MFR was useful as an index related to chronic pain.