Subgroup characteristics in care workers with low back pain: cluster analysis-based severity of central sensitivity syndromes and low back pain.

PURPOSE: This multicentre, collaborative, cross-sectional study aimed to explore the characteristics of subgroups based on central sensitivity syndromes (CSSs) and low back pain (LBP) severity. Furthermore, we investigated the relationship between the classified subgroups and work status among the care workers. PATIENTS AND METHODS: In 660 care workers, we assessed LBP intensity, pain duration, pain sites, CSS (using the central sensitization inventory-9), psychological factors (using the pain catastrophizing scale and pain self-efficacy questionnaire), and work status (interference, amount of assistance, frequency of assistance, and work environment). We used hierarchical clustering analysis to divide the participants into subgroups based on CSS and LBP severity. We further performed multiple comparison analyzes and adjusted the residuals (chi-square test) to reveal differences between clusters. RESULTS: Care workers with LBP were divided into four subgroups (Cluster 1: no CSS and mild LBP, Cluster 2: mild CSS and severe LBP, Cluster 3: mild CSS and mild LBP, Cluster 4: severe CSS and moderate LBP). Cluster 4 tended to have a higher number of pain sites, severe pain catastrophizing, and poor pain self-efficacy. In addition, Cluster 4 showed a higher frequency of assistance and an inadequate working environment and equipment. By contrast, Cluster 2 tended to have low pain self-efficacy. In addition, Cluster 2 experienced the highest work-related interference compared with any of the subgroups. CONCLUSION: Our findings suggested that the severe LBP and severe CSS subgroups had common and different characteristics concerning psychological factors and work status, including interference with work. Our results may help to improve the management of care workers with LBP.

Associations of Central Sensitization-Related Symptoms with Low Back Pain-Related Factors and Work Status in Caregivers.

Low back pain (LBP) is associated with psychological factors and central sensitization-related symptoms (CSSs). The relationship between CSSs, LBP-related factors, and work status in caregivers remain unclear. This multicentre, collaborative, cross-sectional study aimed to determine the association between CSS severity, LBP-related factors, and work status in caregivers with LBP. We measured LBP intensity, pain duration, pain sites, CSSs (using the Central Sensitization Inventory-9: CSI-9), psychological factors (using the Pain Catastrophizing and Pain Self-Efficacy scales), and work status (interference, amount of assistance, frequency of assistance, and work environment) in 660 caregivers. CSS severity was categorised as no (CSI-9:0−9), mild (CSI-9:10−19), or moderate/severe (CSI-9:20−36). We further performed multiple comparison analyses and adjusted the residual chi-square to reveal differences between CSS severity groups. Caregivers with more severe CSSs tended to exhibit worse LBP intensity (p < 0.01), widespread pain (p < 0.01), catastrophic thinking (p < 0.01), and pain self-efficacy (p < 0.01), and they also tended to experience work interference (p < 0.01). Caregivers without CSSs tended to receive a smaller amount of assistance with a lower frequency (p < 0.05). The number of participants with an adequate environment and equipment was significantly less in the moderate/severe CSS group (p < 0.01). Thus, our findings may suggest that CSS severity is associated with LBP intensity, widespread pain, psychological factors, and work status in caregivers.

The attenuating effect of a dynamic cushion on the development of leg edema in wheelchair users with spinal cord injuries.

BACKGROUND: Prolonged wheelchair sitting is known to lead to venous stasis and results in leg edema. OBJECTIVE: To clarify how a dynamic cushion affects leg edema in people with spinal cord injuries (SCI) evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with a dynamic air cushion or a static cushion. METHODS: Seven wheelchair users with SCI participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed 10 cm proximally from the medial malleolus). Following a period of rest, the subjects sat on a reclining wheelchair containing a dynamic cushion for 15 min. Then, the protocol was repeated with a static cushion. The above two procedures were performed in a random order. These data were statistically compared between the two procedures. RESULTS: The change in leg volume observed during sitting on the dynamic cushion (-0.02 ± 0.21 ml/100 ml) was smaller than that observed during sitting on the static cushion (0.18 ± 0.28 ml/100 ml) (P< 0.05). CONCLUSIONS: These results suggested that the dynamic air cushion relieved leg edema induced by wheelchair sitting in individuals with SCI.

Effect of a Dynamic Air Cushion on the Development of Leg Edema during Wheelchair Sitting.

[Purpose] To clarify how a novel dynamic cushion affects the leg edema evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with the dynamic air cushion or a static cushion. [Subjects and Methods] Nine healthy male subjects participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed around the middle portion of the lower thigh). Following a period of rest, each subject was asked to sit on a wheelchair containing the dynamic cushion for 15 min. Then, the protocol was repeated with a static cushion. The angles of the knee and ankle joints were set to 90 degrees, and no footrests were used. [Results] The change in leg volume observed during sitting on the dynamic cushion (0.00 ± 0.03 mL/100 mL) was smaller than that observed during sitting on the static cushion (0.02 ± 0.02 mL/100 mL). [Conclusion] These results suggested that the dynamic cushion relieved leg edema during wheelchair sitting.