Oral Presentation 51st International Society for the Study of the Lumbar Spine Annual Meeting 2025

Effects of isolated lumbar extension resistance exercise on chronic low back pain and radiculopathy related to specific spinal disorders: a multidimensional, closely-monitored, prospective two-arm study (115724)

Bruno Domokos 1 2 , Julia Ettinger 1 2 , Christoph Raschka 1 , Christoph Spang 1 2
  1. University of Wuerzburg, Wuerzburg, Bavaria, Germany
  2. Private Spine Center Dr Alfen, Wuerzburg, Bavaria, Germany

Introduction
Chronic low back pain (CLBP) is a multifaceted condition requiring multimodal treatment approaches for effective management. This complexity necessitates a comprehensive assessment addressing pain and disability but also morphological, functional, physiological, and biomechanical domains [1]. Heavy load isolated lumbar extension resistance exercise (ILEX) has shown clinical promise in treating CLBP [2, 3], though the extent to which ILEX, combined with or without other therapies, can improve various biological and psychosocial parameters remains unclear [4].

Methods
Sixty-one patients with CLBP, lower limb radiculopathies and specific clinical conditions (i.e. disc herniations, spondylolisthesis) were assigned to two groups. Group ILEX+ (n=30; 16 men, 14 women; mean age 42 years) participated in a 25-session ILEX protocol (1–2 sessions per week) combined with manual therapy and general exercise. Group ILEX (n=31; 16 men, 15 women; mean age 40 years) completed 25 sessions with only ILEX. ILEX training was standardized using a pelvic restraint system, with adjustments based on individual progress via software-controlled resistance and range of motion.

Pain (Visual Analog Scale, VAS), disability (Oswestry Disability Index, ODI), and quality of life (SF-36) were assessed at five time points (t1 = baseline, t2 = 3 weeks, t3 = 6 weeks, t4 = 9 weeks, t5 = 16 weeks Furthermore, cross-sectional area (CSA) and muscle thickness (MT) of the lumbar multifidus at L4/L5 (via ultrasound), muscle activity (via electromyography in resting, static-contracted, and dynamic states), isometric maximum strength (ILEX at 39°, 30°, 24°, and 15°), and measures of posture, mobility, and stability (via spinal mouse).

Results
Both groups showed a linear progressing reduction in pain (VAS; ILEX+ t1: 46.45 (mean values), t5: 18.24; ILEX t1 49.05, t5:19.29; p<0.001), disability (ODI; ILEX+ t1: 20%, t5: 9%; ILEX t1: 24%, t5: 8%; p<0.001) and physical and psychological quality of life (SF-36) (p<0.001) along the time course. These reductions in pain were accompanied in a similar manner by significant increases in muscle morphology, as indicated by the growth in CSA and by gains in maximum strength across both groups (CSA; ILEX+ t1: 8.07 cm²; t5: 8.82 cm² ; ILEX t1: 7.93cm²; t5: 8.49cm²) / Strength (30°); ILEX+ t1: 181.07 Nm, t5: 262.24 Nm; ILEX t1: 171.68 Nm, t5: 255.29 Nm) (all p<0.001) (Fig. 1). Pain improved in a similar proportion of patients in ILEX+ (86%) and ILEX (90%). No differences between groups were found for any value. However, electromyographic and biomechanical parameters (posture, mobility, stability) showed no notable changes in either group.

67376ffb2b7ab-ISSLS_2025_ILEX+-+Graphs+VAS+ODI+CSA+Strength.png

Discussion
This is the first study to closely monitor multiple dimensions—including morphological, physiological and psychological factors—in an ILEX-based therapy program for specific back disorders. The findings demonstrate that ILEX, with or without adjunctive therapies, effectively reduces pain and disability while improving quality of life. Both groups exhibited comparable improvements in muscle morphology and strength, suggesting the primary benefits of ILEX are driven by muscular adaptations rather than neuromuscular or biomechanical functions. Future research should investigate long-term effects and focus on how the interplay of different dimensions contributes to a better understanding of pathomechanisms and ILEX-induced rehabilitation effects.

  1. Matheve, T., Hodges, P. & Danneels, L. (2023). The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications. J. Clin. Med., 12(17), 5510. doi: 10.3390/jcm12175510.
  2. Steele, J., Bruce-Low, S. & Smith, D. (2015). A review of the clinical value of isolated lumbar extension resistance training for chronic low back pain. PM&R, 7(2), 169–187. doi: 10.1016/j.pmrj.2014.10.009.
  3. Golonka, W., Raschka, C., Harandi, V. M., Domokos, B., Alfredson, H., Alfen, F. M. & Spang, C. (2021). Isolated lumbar extension resistance exercise in limited range of motion for patients with lumbar radiculopathy and disk herniation—Clinical outcome and influencing factors. J. Clin. Med., 10(11), 2430. doi: 10.3390/jcm10112430.
  4. Fortin, M., Rye, M., Roussac, A., Montpetit, C., Burdick, J., Naghdi, N., et al. (2023). The Effects of Combined Motor Control and Isolated Extensor Strengthening versus General Exercise on Paraspinal Muscle Morphology, Composition, and Function in Patients with Chronic Low Back Pain: A Randomized Controlled Trial. J. Clin. Med., 12(18), 5920. doi: 10.3390/jcm12185920.