(Golden Oldie) Is a positive clinical outcome after exercise therapy for chronic non-specific low back pain contingent upon a corresponding improvement in the targeted aspect(s) of performance? A systematic review

Our take

When exercise therapy helps chronic low back pain, is it because the exercise actually improved the specific thing it targeted, like strength, flexibility, or endurance?

This review found little evidence that the pain and disability benefits of exercise for chronic non-specific low back pain are explained by improvements in the targeted physical performance, such as strength, mobility, or endurance. The benefit may work through other mechanisms instead.

ChallengesRead paper

Systematic review16 Trials1,476 ParticipantsModerate evidence

Key points

Exercise helps chronic low back pain but only with modest effect sizes.
Across the included studies, improvements in pain and function rarely tracked with improvements in trunk mobility, strength, or endurance.
Of the studies examining mobility, 9 found no correlation and only 1 found a weak association with clinical improvement.
Benefits may instead be driven by central, psychosocial, and motor control mechanisms rather than muscle or joint performance gains.

How it was conducted

Design: Systematic review of correlation between clinical outcomes and targeted performance changes
Databases: Medline, Embase, Cochrane, Cinahl, and PEDro, searched to April 2010
Included studies: 16 studies
Participants: 1476 across included studies
Outcomes examined: Correlation of pain and disability with mobility, trunk extension and flexion strength, and endurance

What they found

For mobility, 9 studies found no correlation and 1 found only a weak correlation with clinical improvement.
Trunk extension and flexion strength changes showed little association with pain or function improvement.
Endurance improvements showed little association with clinical improvement.
Disability versus mobility and strength likewise showed weak associations.

Limitations

Based on correlation between outcomes rather than experimental manipulation, so it cannot prove the absence of a mechanistic link.
Included studies were heterogeneous in exercise type, performance measures, and outcome assessment.
The search extends only to April 2010, so more recent trials are not included.
The available record provides limited numerical detail, with no pooled effect estimates or confidence intervals reported here.

Why it matters

For patients: If exercise eases your back pain, the relief does not necessarily mean your back got stronger or more flexible, and that is fine.
For clinicians: Do not assume clinical improvement from exercise requires measurable gains in the targeted strength, mobility, or endurance, and consider central and psychosocial factors.
For readers: This review questions the common assumption that exercise relieves chronic low back pain by fixing a specific physical deficit.

Source

doi:10.1007/s00586-011-2045-6

Read the original paper

Clinically assessing this area? See the lumbar spine & low back special tests.