An investigation into the efficacy of strain-counterstrain technique to produce immediate changes in pressure pain thresholds in symptomatic subjects

Abstract

Background and objective: Strain counterstrain (SCS) is an osteopathic technique used by osteopaths and manual therapists for the relief of musculoskeletal pain and associated dysfunction. Limited literature exists to support the efficacy of SCS technique. This dissertation is presented in two sections. Section one is a literature review of SCS technique and the proposed outcome measures. Section two is the research conducted presented as a manuscript in the style required by the International Journal of Osteopathic Medicine. The second section is supported by three appendices of material not intended for publication. The aim of this study was to investigate the efficacy of SCS technique on subjects with a history of a recreational sports injury of the upper extremity.

Design: Randomized assessor blinded placebo controlled trial.

Methods: Twenty three subjects (13 males, 10 females; mean age=26.1, SD=6.3) fulfilled the requirements for the study. Subjects were screened to establish the presence of a primary tender point (TeP) around the elbow joint. Subjects were randomly assigned into two groups and received either an SCS intervention or a Sham intervention. The primary outcome measures were pressure pain threshold (PPT) on the primary TeP, and visual analog scale (VAS) assessing local pain intensity elicited by the application of approximately 3kg/cm2 of pressure on the primary TeP. The secondary outcome measure was pain-free grip strength (PFGS).

Results: Within group changes showed a significant improvement in VAS for pain intensity following the SCS intervention (p<0.001) compared with the Sham intervention (p=0.053). Pre-post effect sizes for the VAS for pain intensity were ‘large’ in the SCS intervention group (d=1.87) and ‘moderate’ (d=0.90) for the Sham intervention group. Both groups surpassed the minimal clinically important difference (MCID) defined as a decrease ≥30% in VAS for pain intensity (SCS group=55%, Sham group=31%). Within group changes showed a small improvement for PPT at the TeP following either the SCS intervention (p=0.497) compared with the sham intervention (p=0.749). Pre-post effect sizes for the TeP were small in the SCS intervention group (d=0.29) and trivial (d=0.14) for the sham intervention group. No significant differences were found for the PFGS (SCS: p=0.936 d=0.03, Sham: p=0.989 d=0.01)

Conclusions: The results indicate that SCS technique may be an efficacious technique in treatment of TePs around the elbow in subjects with a history of a recreational sports injury of the upper extremity. SCS technique can produce decreases in pain intensity as reported from mechanical pressure at a primary TeP.