Special Poster Session 51st International Society for the Study of the Lumbar Spine Annual Meeting 2025

Biomechanical assessment of individuals with chronic low-back pain during baseline performance-based testing using wearable motion sensors (115769)

Rachel Roos 1 , Zakiy Alfikri 1 , Anna Bailes 1 2 , Marit E Johnson 3 , Sebastian Murati 1 2 , Harold Cook 1 , William W Clark 4 , Bambang Parmanto 5 , Leming Zhou 5 , Jessa Darwin 6 , Gina McKernan 6 , Gwendolyn A Sowa 3 6 , Kevin M Bell 1
  1. Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States of America
  2. Department of Physical Therapy, University of Pittsburgh, Pittsburgh, PA, United States of America
  3. Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, United States of America
  4. Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, PA, United States of America
  5. Department of Health Information Management, University of Pittsburgh, Pittsburgh, PA, United States of America
  6. Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States of America

INTRODUCTION: Chronic low back pain (cLBP) is one of the most prevalent and costly musculoskeletal disorders in adolescents and adults globally¹,². Assessments of spinal and hip kinematics can help identify atypical movement patterns in individuals with cLBP. This study aimed to characterize lumbopelvic kinematics during functional movements.

METHODS: Data from the Low Back Pain: Biological, Biomechanical, Behavioral Phenotypes (LB³P) study were analyzed following the protocol listed by Vo et al.³ Four inertial measurements units (IMUs) (Figure 1A, Figure 1B) were placed at T1/T2, T12/L1, and L5/S1 and on the right femur (Figure 2). Participants performed trunk movements to their maximum range of motion (Flexibility ROM tests: Axial Rotation (AR), Lateral Bending (LB), Flexion/Extension (F/E)) and at their fastest speed (Dynamic Motion tests: AR, LB, Flexion). Additional performance-based tests (Combined Rotation/Flexion, 5 Times Sit-to-Stand, and Postural Lifting Strategy) were completed.

Range of motion (ROM), velocity, acceleration, and lumbopelvic rhythm (LPR) were calculated using IMU accelerometer and gyroscope data in MATLAB 2022a. LPR was calculated by normalizing excursion during the F/E movement for the L1/L5 and Hip/L5 segments to their maximum values. Data analysis began after 1° of hip excursion up to 98% of the maximum movement. The ratio of normalized lumbar to hip movement was extracted for the first two quartiles of each movement.

 

RESULTS: Analysis of 954 participants’ data revealed distinct patterns across sex (female and male) and age groups (<60 and ≥60). Due to non-normal distributions, median (interquartile range (IQR)) values were reported. For Flexibility tests, females and participants under 60 demonstrated greater total excursion for the T1/L5, T1/L1, and L1/L5 segments. Hip/L5 segment patterns varied; male/older had the most AR excursion, male/younger participants had the most LB excursion, and female/older participants had the most F/E excursion.

In Dynamic tests, sex differences were pronounced in AR velocity and acceleration (T1/L5: female: 100.6°/s and 614.9°/s2; male: 79.8°/s and 502.2°/s2). For the first quartile of neutral-to-flexion, females and participants <60 had slightly higher LPRs (1.3 (0.7–2.1) and 1.4 (0.7–2.1), respectively) than males and participants ≥60 (1.2 (0.6–1.7) and 1.1 (0.5–1.7)). In neutral-to-extension, LPRs were similar between sexes (0.9) but lower for older participants (0.8 (0.4–1.3) vs. 1.0 (0.5–1.5)).

 

DISCUSSION: Findings align with literature showing age-related reduction in ROM and variable sex-based differences vary depending on movement type. Females and younger participants generally exhibited greater ROM, except in some Hip/L5 movements, where males and older participants had greater ROM. Sex differences were more apparent in velocity than acceleration, while age-related differences were consistent for both velocity and acceleration, with younger participants generally demonstrating higher values. LPR analysis indicated females and younger participants used their lumbar segments more readily during neutral-to-flexion, while male and older participants favored pelvic movement slightly more during the beginning of neutral-to-extension. Future work should focus on quantifying the clinical significance of movement trends and exploring how metrics like ROM, velocity, and acceleration can refine the identification of demographic-specific movement strategies in individuals with cLBP. 673800516967a-Figure+1A.jpg673800516967a-Figure+1B.jpg673800516967a-Figure+2.jpg

  1. 1) GBD 2021 Low Back Pain Collaborators, Lancet Rheumatol, 2023.
  2. 2) GBD 2019 Diseases and Injuries Collaborators Lancet, 2020.
  3. 3) Vo N V, et al., Pain Med, 2023.
  4. 4) Arshad R, et al., J Biomech, 2019.