Impact of load expectations on neuromuscular and postural strategies during a freestyle lifting task in individuals with and without chronic low back pain

Objective This study aimed to investigate how load expectations modulate neuromuscular and postural strategies in the anticipation of a freestyle lifting task with varying expected loads in individuals with and without chronic low back pain (cLBP). Methods Forty-seven participants, 28 with cLBP pain and 19 without, were recruited and completed a series of freestyle lifting trials (3 sets of box lifted for a total of 36 lifts). Verbal cues were used to modulate their expectations about the boxes’ weight: no expectation, lighter or heavier load expectations. Following each set, participants rated their perceived exertion on a visual analog scale. During the lifting protocol, kinematics (time to maximal flexion, angular velocity and joint angles), electromyography muscle activity (erector spinae and quadriceps) and center of pressure displacement were simultaneously recorded. Results Results showed that time to maximal knee flexion was modulated by load expectations in both groups (mean lighter load expectations = 1.15 ± 0.32 sec.; mean heavier load expectations = 1.06 ± 0.31 sec.). Results also showed a load expectations X group interaction for that time to maximal hip and lumbar flexion. Time to maximal hip flexion decreased with heavier load expectations (mean lighter load expectations = 1.20 ± 0.36; mean heavier load expectations = 1.16 ± 0.33) for cLBP only. Time to maximal lumbar flexion increased with heavier load expectation (mean lighter load expectations = 1.41 ± 0.27 sec.; mean lighter load expectations = 1.46 ± 0.29 sec.) for participants without LBP. However, no difference in lumbar, hip nor knee angles were observed between groups or conditions. Results highlighted significant load expectation effects for erector spinae electromyography activity, as lower muscle activations was observed for both groups with heavier load expectations (mean = 0.32 ± 0.15), compared to lighter load expectations (mean = 0.52 ± 0.27). Force plates analyses did not reveal any significant load expectation effects. Conclusion Present findings showed that load expectations modulate movement strategies and muscle activation similarly but not identically in individuals with chronic low back pain and healthy adults during freestyle lifting. Results of the present study partially differ from previous studies and suggest only minor differences in lifting strategies between healthy individuals and individuals with cLBP experiencing low level of pain and disability. More studies are needed to investigate the potential role of load expectations in the development and persistence of chronic low back pain.

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A Comparison of Abdominal Muscle Thickness Changes After a Lifting Task in Subjects With and Without Chronic Low-Back Pain

Human Factors The Journal of the Human Factors and Ergonomics Society ◽

10.1177/0018720814544213 ◽

2014 ◽

Vol 57 (2) ◽

pp. 208-217 ◽

Cited By ~ 2

Author(s):

Tahere Seyed Hoseinpoor ◽

Sedighe Kahrizi ◽

Bahram Mobini ◽

Mohsen Naji

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Chronic Low Back Pain ◽

Muscle Thickness ◽

Abdominal Muscle ◽

Low Back ◽

Lifting Task

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A Graded Exposure, Locomotion-Enabled Virtual Reality App During Walking and Reaching for Individuals With Chronic Low Back Pain: Cohort Gaming Design (Preprint)

10.2196/preprints.17799 ◽

2020 ◽

Author(s):

Rebecca White Hennessy ◽

Deanna Rumble ◽

Mike Christian ◽

David A Brown ◽

Zina Trost

Keyword(s):

Virtual Reality ◽

Low Back Pain ◽

Back Pain ◽

Chronic Low Back Pain ◽

Perceived Exertion ◽

Rating Of Perceived Exertion ◽

Low Back ◽

Progressive Movement ◽

System Usability Scale ◽

Graded Exposure

BACKGROUND Chronic low back pain (cLBP) can interfere with daily activities, and individuals with elevated pain-related fear (also known as kinesiophobia or the fear of injury due to movement) can develop worse long-term disability. Graded exposure (GEXP) protocols use successive participation in avoided activities to help individuals overcome fearful movement appraisals and encourage activity. We sought to develop a series of GEXP virtual reality (VR) walking and reaching scenarios to increase the exposure and engagement of people with high kinesiophobia and cLBP. OBJECTIVE This study aims to (1) determine GEXP content validity of the VR application and (2) determine the feasibility of individuals with cLBP performing locomotion-enabled physical activities. METHODS We recruited 13 individuals with cLBP and high pain-related fear to experience six VR modules, which provide progressive movement exposure over three sessions in a 1 week period. At session 1, participants ranked each module by likelihood to avoid and assigned an expected pain and concern for harming their back rating to each module. Participants provided a rating of perceived exertion (RPE) after experiencing each module. To test feasibility, we administered the system usability scale (SUS) and treatment evaluation inventory (TEI) following the final session. In addition, we measured pain and pain-related fear at baseline and follow-up. RESULTS The 12 participants who completed the study period assigned higher avoidance (P=.002), expected pain (P=.002), and expected concern (P=.002) for session 3 modules compared with session 1 modules. RPE significantly increased from session 1 (mean 14.8, SD 2.3) to session 3 (mean 16.8, SD 2.2; P=.009). The VR application showed positive feasibility for individuals with cLBP through acceptable SUS (mean 76.7, SD 13.0) and TEI (mean 32.5, SD 4.9) scores. Neither pain (P=.20) nor pain-related fear (P=.58) changed significantly across sessions. CONCLUSIONS The GEXP VR modules provided progressive exposure to physical challenges, and participants found the VR application acceptable and usable as a potential treatment option. Furthermore, the lack of significant change for pain and pain-related fear reflects that participants were able to complete the modules safely.

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Chronic Low Back Pain in Women: Muscle Activation during Task Performance

Journal of Physical Therapy Science ◽

10.1589/jpts.25.1569 ◽

2013 ◽

Vol 25 (12) ◽

pp. 1569-1573 ◽

Cited By ~ 8

Author(s):

Fernanda G Santos ◽

Carolina M Carmo ◽

América C Fracini ◽

Rita R P Pereira ◽

Kelly S Takara ◽

...

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Task Performance ◽

Chronic Low Back Pain ◽

Muscle Activation ◽

Low Back

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The Amount and Temporal Structure of Center of Pressure Fluctuations During Quiet Standing in Patients With Chronic Low Back Pain

Motor Control ◽

10.1123/mc.2018-0032 ◽

2020 ◽

Vol 24 (1) ◽

pp. 91-112

Author(s):

Fatemeh Azadinia ◽

Ismail Ebrahimi-Takamjani ◽

Mojtaba Kamyab ◽

Morteza Asgari ◽

Mohamad Parnianpour

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Chronic Low Back Pain ◽

Healthy Subjects ◽

Postural Sway ◽

Center Of Pressure ◽

Pressure Fluctuations ◽

Quiet Standing ◽

Low Back ◽

Nonlinear Parameters

The characteristics of postural sway were assessed in quiet standing under three different postural task conditions in 14 patients with nonspecific chronic low back pain and 12 healthy subjects using linear and nonlinear center of pressure parameters. The linear parameters consisted of area, the mean total velocity, sway amplitude, the SD of velocity, and the phase plane portrait. The nonlinear parameters included the Lyapunov exponent, sample entropy, and the correlation dimension. The results showed that the amount of postural sway was higher in the patients with low back pain compared with the healthy subjects. Assessing the nonlinear parameters of the center of pressure showed a lower sample entropy and a higher correlation dimension in the patients with low back pain compared with the healthy subjects. The results of this study demonstrate the greater regularity and higher dimensionality of the center of pressure fluctuations in patients with nonspecific chronic low back pain, which suggests that these patients adopt different postural control strategies to maintain an upright stance.

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Effects of lumbosacral orthosis on dynamical structure of center of pressure fluctuations in patients with non-specific chronic low back pain: A randomized controlled trial

Journal of Bodywork and Movement Therapies ◽

10.1016/j.jbmt.2019.01.014 ◽

2019 ◽

Vol 23 (4) ◽

pp. 930-936

Author(s):

Fatemeh Azadinia ◽

Ismail Ebrahimi-Takamjani ◽

Mojtaba Kamyab ◽

Morteza Asgari ◽

Mohamad Parnianpour

Keyword(s):

Randomized Controlled Trial ◽

Low Back Pain ◽

Back Pain ◽

Chronic Low Back Pain ◽

Center Of Pressure ◽

Controlled Trial ◽

Pressure Fluctuations ◽

Dynamical Structure ◽

Low Back ◽

Randomized Controlled

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WAVELET ANALYSIS OF LOW BACK SURFACE EMG SIGNALS SUBJECT TO UNEXPECTED LOAD

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519404001004 ◽

2004 ◽

Vol 04 (03) ◽

pp. 389-400 ◽

Cited By ~ 1

Author(s):

M. H. POPE ◽

N. D. PANAGIOTACOPULOS ◽

W. STIELAU ◽

K. FRIESEN ◽

J. S. LEE

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Reaction Time ◽

Chronic Low Back Pain ◽

Erector Spinae ◽

Back Surface ◽

Initial Reaction ◽

Clinical Test ◽

Low Back ◽

Normal Subject

This study reports a new technique for the analysis of electromyographic signals from the low back muscles. More specifically, the effect of unexpected load on a normal subject and a subject with chronic low back pain was determined and quantified using wavelet based analysis (Morlet wavelet). The analysis was performed using a Wavelet software system, subsequently referred to as PSCW. The system identified automatically, accurately, and in a uniquely reproducible manner the time response of the erector spinae muscle. The exact number of responses as well as their corresponding time and amplitude were determined and tabulated. It was observed that the initial reaction time for the normal subject was faster than the reaction time for the subject chronic low back pain. The importance of this observation may help in the understanding of the physiology of the neuromuscular system associated with low back spine disorders. It is believed that an occupational and clinical test based on this observation that could give an accurate assessment of the status of low back disorder could be designed. Based on this assessment a rehabilitation program could be developed with the objective of improving the condition of a spine disorder (decrease the initial response time) by muscle strengthening.

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