The research...
A study by Risch looked at the effects
of exercise for isolated lumbar extensor muscles in 54 chronic
low back pain patients. Results showed a significant
increase in isometric lumbar extension strength for the
treatment group and a significant reduction in reported
pain compared with the control group.
Risch et al., SPINE 1993 - COPY AVAILABLE
A study by Nelson that looked at outcomes for 627 chronic
low back pain patients who completed a programme whose primary
treatment was intensive, specific exercise using firm pelvic
stabilization to isolate and rehabilitate the lumbar spine
musculature found that 76% of patients experienced "both
substantial pain relief and substantial improvement in strength"
compared to a control group of 107 patients that were not
treated.
Nelson et al. ORTHOPEDICS, Oct 1995 - CLICK TO READ
A prospective, controlled study by Manniche found that
a course of high intensity lumbar extension exercise produced
a 70% decrease in reported subjective pain for chronic low
back patients.
Manniche et al. PAIN 1991