|Summary of results for studies that investigated intervention effects on the Flexion relaxation response (FRR)|
|Muscle activity patterns of FRR (electrical patterns of activity in extensor muscles during flexion and return from flexion) (Standardised mean difference and 95% confidence intervals, negative values favour experimental group)|
|Study and intervention type||Study details||Movement pattern Was there a statistically significant difference (p > 0.05) in physical parametersbetweengroups?||Health outcomes Was there a statistically significant difference (p < 0.05) in health outcomes between groups? groups?|
|No. of subjects||Baseline differences between groups?||FRR* Upper lumbar (T12-L3/4)||FRR* Lower lumbar (L4-S1)||Angle of onset and cessation for FRR||Extension vs flexion EMG ratio||Pain||Activity|
|Lalanne 2009‡Manipulation vs sham||27||No||Yes ↑ -1.40 (−2.24, -0.56)||No||No||Not measured||No||Not measured|
|Mannion 1999 & 2001Physiotherapyvs aerobics Physiotherapy vs device strength training||99||No||No†Insufficient data||No†Insufficient data||Not measured||Not measured||No||No|
|Marshall 2008Swiss ball vs general exercise||50||No||No||Yes ↑ FRR in favour of intervention group −1.60 (−2.25, -0.94)||Not measured||Not measured||No||Yes Activity −0.77 (−1.34 to −0.19)|
|Ritvanen 2007Traditional bone setting vs physiotherapy||61||(Intervention group had right vs left differences pre and post treatment)||No||No (both groups showed ↓ FRR post intervention||Not measured||No Trend towards increase for both groups||No||No|
* FRR = Flexion relaxation ratio (the amount of electrical activity in lumbar extensor muscles during flexion compared with end of flexion range of movement).
†As reported by authors. Insufficient data for analysis.
‡Single session intervention with pre and post analysis within session.
Laird et al.
Laird et al. BMC Musculoskeletal Disorders 2012 13:169 doi:10.1186/1471-2474-13-169