Investigation of Trunk Muscle Size and Function in Older Adults With Chronic Low Back Pain

Summary

Rehabilitative Ultrasound Imaging (US) is a procedure used to evaluate skeletal muscle size and function to inform clinical practice. US has been shown to be a reliable and valid tool for measuring changes in trunk muscle (i.e. abdominal and back muscle) size and activity during sub-maximal contractions in younger populations. Younger adults with low back pain as compared with healthy adults without pain demonstrate smaller back muscle size, lower back muscle activity, and greater back muscle asymmetry (differences in right side compared with left side).

No trials are published evaluating muscle adaptations using US in response to clinical treatments for low back pain in the older adult population. Increased muscle size and improved muscle symmetry have been reported in younger adults with low back pain who participate in low back stabilization exercises. These exercises use voluntary contractions of the back muscles with prolonged hold times and low loads. Neuromuscular Electrical Stimulation (NMES) is a treatment modality that increases muscle activity when voluntary activity is impaired and increases muscle size. Most studies assessing muscle size and activity in response to NMES have been conducted in the knee muscles (i.e. the quadriceps), while the impact of NMES on the back muscles remains relatively unexplored. Given the potential to evaluate back muscle size and activity with US, this assessment tool may be used to document muscle adaptations to a clinical intervention in older adults with low back pain.

The purpose of this study is to conduct a 6-week clinical trial to determine if NMES plus lumbar stabilization exercises (i.e. NMES AND Stabilization Exercises) is superior to lumbar stabilization exercises (i.e. Moist Heat AND Stabilization Exercises) for improving back muscle size, activity, and side-to-side (i.e. right side versus left side) symmetry in older adults with chronic low back pain (i.e. low back pain of greater than 3 months). Muscle size, activity, and symmetry will be assessed using US before and after the treatments to determine if the treatments positively impact muscle. Secondary clinical measures of success will include improvements in physical, psychological, and social function pre- to post-treatment.

Conditions

• Low Back Pain

Interventions

OTHER

Neuromuscular Electrical Stimulation

Neuromuscular Electrical Stimulation (NMES) to the low back muscles (i.e. spinal extensors) will be applied at the parameters previously used in the knee muscles at the maximal tolerable intensity, which results in a full, sustained isometric contraction of the back muscles. Pad placement will be just below the waist line, with 2, 2X2 inch pads, on either side of the spine. Participants will be positioned on their belly with 2 pillows under their stomach to level the spine and secured to a table using a belt that crosses the buttock. The lumbar stabilization program will include exercises targeting the back muscles in three positions: standing, prone (belly), and quadruped (hands and knees).

OTHER

Moist Heat

For participants who do not receive NMES, moist heat will be applied for 15 minutes in a position of comfort for the participant. The lumbar stabilization program will include exercises targeting the back muscles in three positions: standing, prone (belly), and quadruped (hands and knees).

Sponsors & Collaborators

• University of Delaware

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

60 Years

Max Age

85 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-02-14

Primary Completion

2011-11-22

Completion

2011-11-22

Countries

• United States

Study Locations