M. Liechti1, M. von Arx1, P. Eichelberger1, C. Bangerter1,2, M.L. Meier3,4, S. Schmid1,2
1Spinal Movement Biomechanics Group, Bern University of Applied Sciences, Division of Physiotherapy, School of Health Professions, Bern, Switzerland, 2University of Basel, Faculty of Medicine, Basel, Switzerland, 3Integrative Spinal Research, Balgrist University Hospital, University of Zurich, Department of Chiropractic Medicine, Zurich, Switzerland, 4University of Zurich, Zurich, Switzerland
Background: Fear-avoidance beliefs, particularly pain-related fear is often described in connection with activities involving the lower back such as object lifting. Lifting with a straight back is commonly believed to be safe, whereas lifting with a round back is perceived as dangerous. However, literature provides no conclusive evidence for justifying these assumptions.
Fear of lifting with a flexed spine is associated with reduced spinal motion during object lifting in low back pain (LBP) patients and healthy pain-free individuals, indicating that pain-related fear might play a role in lifting behavior in absence of pain. Further, LBP patients also showed changes in the spatial distribution of back muscle activity during lifting, but it remains unknown whether such associations are also present in pain-free individuals.
Fear of lifting with a flexed spine is associated with reduced spinal motion during object lifting in low back pain (LBP) patients and healthy pain-free individuals, indicating that pain-related fear might play a role in lifting behavior in absence of pain. Further, LBP patients also showed changes in the spatial distribution of back muscle activity during lifting, but it remains unknown whether such associations are also present in pain-free individuals.
Purpose: This cross-sectional observational study investigated the relationship between pain-related fear and the spatial distribution of lumbar paraspinal muscle activity in pain-free individuals during a repetitive lifting task.
Methods: Thirty healthy pain-free participants (m/f: 20/10; age: 31.8 ±8.5 years; BMI: 23.3 ±2.4 kg/m2) completed the Tampa Scale for Kinesiophobia for the general population (TSK-G, total score used) and the Photograph Series of Daily Activities- Short electronic Version (PHODA-SeV, score of item PHODA-lift used). They were asked to perform 25 repetitions of lifting a 5kg-box from a lower shelf (knee height) to an upper shelf (shoulder height) and back, while multi-channel electromyographic signals were recorded bilaterally from the lumbar erector spinae muscles. Changes in spatial distribution were defined as the differences in vertical position of the weighted centroids of muscle activity (centroid shift) between the start phase (average of lifting cycle 2- 4) and end phase (average of lifting cycle 22- 24) of the lifting task. Linear regression analyses were performed to examine the relationships between centroid shift and pain-related fear scores.
Results: Mean scores of the pain-related fear questionnaires were 32.3 (SD 6.22, range 21- 49) for the TSK-G and 42.5 (SD 27.9, range 4- 100) for the PHODA-lift. Fear of lifting an object with a flexed spine (represented by the PHODA-lift score) was negatively associated with erector spinae activity centroid shift (R2 adj. = 0.1832; p = 0.045) during lifting-up phase.
Conclusions: The relationship between changes in vertical centroid position of erector spinae muscles activity and the fear of lifting an object with a flexed spine, might be an expression of behavioral alterations to prevent the back from possible harm.
More specifically, the association of muscle activity and pain-related fear in healthy individuals, suggests an active protective strategy among participants, which should be further investigated with different lifting tasks, lifting weights and the potential resulting muscular fatigue or onset of low back pain.
More specifically, the association of muscle activity and pain-related fear in healthy individuals, suggests an active protective strategy among participants, which should be further investigated with different lifting tasks, lifting weights and the potential resulting muscular fatigue or onset of low back pain.
Implications: This study contributes to a better understanding of psychomotor interactions during daily activities such as lifting in pain-free individuals. Further, this study highlights the importance of investigating lifting behavior and pain-related fear not only in LBP patients but also in the general population to assess potential behavioral adaption as well as future provocation of low back pain.
Funding acknowledgements: None
Keywords:
Fear of movement
Multi-channel electromyography
Lower back
Fear of movement
Multi-channel electromyography
Lower back
Topics:
Musculoskeletal: spine
Musculoskeletal: spine
Did this work require ethics approval? No
Reason: The local ethics committee provided exemption for this study (Kantonale Ethikkommission Bern, Req-2020–00364) and prior collection of any personal or health related data all participants provided written informed consent.
All authors, affiliations and abstracts have been published as submitted.
