Disc Herniation, Low Back Pain and Core Muscle
Conditions
Keywords
low back pain, exercise, physical therapy, surgery
Brief summary
Low back pain (LBP) is a condition that affects a majority of the US population and is responsible for a significant proportion of health care costs and utilization. Lumbar spine muscle is compromised in LBP, and do, and do not, respond to exercise based physical therapy program depending on measurements representing activation capacity of lumbar muscle. Here, we will characterize the neurological and muscle specific features that may contribute to limited activation in an attempt to identify sources of resistance to recovery in patients with chronic disc injury and identify precision rehabilitation approaches for this complex population of individuals.
Detailed description
Low back pain (LBP) is a complex condition that affects 65-85% of the population, and is the leading musculoskeletal condition contributing to disability in the United States. Disc injury is the most common injury and 75% of individuals undergoing surgical and rehabilitative interventions for this condition experience suboptimal or poor outcomes. These patients demonstrate disability and deficits in functional capacity, and paraspinal muscles in these individuals have been shown to be altered in volume, composition, and mechanical properties. These maladaptive changes influence the ability for the muscle to respond appropriately to rehabilitation efforts in a subgroup of individuals with chronic back pain who do not demonstrate the expected acute activation responses to exercise. While the structural and adaptive capacities of healthy muscle are well understood, pathological muscle recovery and activation deficits are less clear and may be influenced by neurogenic and/or muscle specific impairments. To address this gap in knowledge, the purpose of this trial is to compare central and peripheral origins of impaired activation in individuals with chronic disc injury who do, and do not respond to exercise. Experiment 1 will use a novel functional MRI technique and electromyographic measurements to compare responder and non-responder groups in patients with chronic lumbar disc injury undergoing standard physical therapy. Experiment 2 will compare corticomotor excitability and intracortical inhibition and facilitation between individuals who are undergoing physical therapy or surgery who do and do not respond to exercise. Experiment 3 will compare ex vivo passive and active mechanical responses, and transcriptomics from intraoperative multifidus biopsies of patients undergoing spinal surgery for chronic lumbar disc injury to evaluate muscle mechanotransduction. These experiments will elucidate the neurogenic and muscle-specific contributions to muscle adaptation in the presence of chronic lumbar spine pathology and pain.
Interventions
BEHAVIORALResistance exercise
An acute bout of a 3 minute resistance exercise will be performed using a lumbar extension exercise machine
Sponsors
University of California, San Diego
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Surgical group: * Individuals diagnosed with chronic disc injury (symptoms \> 3 months), * Individuals planning to undergo a spinal surgery to address the diagnosis of chronic disc injury Physical Therapy Group- * Individuals diagnosed with chronic disc injury (symptoms \>3 months), * Individuals initiating an exercise-based physical therapy program to address the diagnosis of chronic disc injury Healthy Control group - * Individuals with no history of chronic back pain (interfering pain lasting \>3 months) within the past 3 years, * no significant spinal pathology beyond normal age-related degenerative changes
Exclusion criteria
* Surgery/Physical therapy groups-History of lumbar spine surgery * Diabetes * Neuromuscular diseases * Epilepsy or other seizure disorder -Healthy control group - * History of lumbar spine surgery * History of interfering pain lasting \>3 months * Diabetes * Neuromuscular diseases * Epilepsy or other seizure disorder
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| RMS amplitude of paraspinal muscle EMG | Baseline | Average RMS EMG amplitude of the lumbar multifidus over the duration of the acute exercise bout. |
| IVIM responsiveness | Baseline | Response classification from IVIM MRI imaging as an increase in IVIM Diffusion (D) of at least 0.055 x 10-3 mm2/s and a pseudodiffusion (D\*) increase of at least 6.94 x 10-3 mm2/s in response to the acute exercise stimulus |
| Cortical excitability | Baseline | Transcranial Magnetic Stimulation based motor threshold of activation of the lumbar multifidus muscle |
| pAMPK | Time of surgery/biopsy | Mechanically-induced phosphorylation of p38 MAPK-Thr180/Tyr182 (p-p38T180/Y182) from intraoperative multifidus biopsies or biopsy needle |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| MEP amplitude | Baseline | Motor evoked potential of multifidus in response to Transcranial Magnetic Stimulation of the motor cortex |
| Cortical Silent Period | Baseline | Period of motor silence in the multifidus after Transcrianial Magnetic Simulation MEP over the motor cortex |
| Short Interval Intracortical Inhibition (SICI) | Baseline | Measurement of signal loss in the multifidus after a paired pulse stimulation of the motor cortex using transcranial magnetic stimulation |
| Short Interval Intracortical Facilitation (SICF) | Baseline | Measurement of time of multifidus muscle activation after a paired pulse transcranial magnetic stimulation of the motor cortex |
| p-mTORS2448/total mTOR | Time of surgery/biopsy | Structural Proteins and phosphorylation of p-mTORS2448/total mTOR measured from intraoperative multifidus biopsies or biopsy needle |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORBahar Shahidi, PT, PhD
UC San Diego
Outcome results
None listed