‘Strain-Counterstrain’(SCS), is a paradigm proposed for the assessment and treatment of musculoskeletal pain and disability (Jones et al., 1995; Kusunose, 1993) that was conceived and developed by an American Osteopathic physician, Lawrence Jones, who claimed that anatomically defined, digitally tender points (DTPs) in the superficial tissue of patients were signs of neuromuscular dysfunction and that these points could be used to guide specific passive body positioning to rectify these dysfunctions (Jones et al., 1995; Kusunose, 1993). Prior to the research discussed in this thesis, DTPs had not been scrutinised and compared to DTPs of other paradigms and had not been comprehensively quantitatively examined. There was a lack of controlled evidence that SCS treatment elicited a reduction in tenderness at DTPs, as claimed by proponents of SCS, and no randomised clinical trials had been conducted to test the effect of SCS treatment.
An extensive literature review compared the DTPs of the SCS paradigm with those of other paradigms and discussed DTPs with reference to models of pain and dysfunction of muscle and joints. It was contended that the processes underlying DTPs are yet to be fully elucidated and that peripheral and central pain processing mechanisms as well as local muscle processes might be involved. It was proposed that the DTPs from the SCS (Jones et al., 1995) and Myofascial pain syndrome (MPS) (‘trigger points’) (Simons et al., 1999) paradigms are not clearly distinct entities. A conclusion was that since clinicians routinely identify and use DTPs in treatment of musculoskeletal conditions there was a need for investigation to elucidate them, determine their homogeneity and importance in assessment and treatment.
In the first of the thesis studies, comprehensive quantitative sensory testing of DTPs (identified using SCS procedures) and contralateral non-tender points in the low back region was conducted. A significant finding was that these DTPs demonstrated reduced electrical detection and electrical pain thresholds. It was hypothesised that this may be indicative of altered central pain processing. The second study indicated that SCS treatment does appear to cause a reduction in tenderness at DTPs in the low back that exceeds the reduction seen with a manual contact control although the mechanism by which SCS treatment acts remains unclear. The final study was the first randomised clinical trial of SCS technique for treatment of acute low back pain or indeed of any condition. The addition of SCS treatment to advice and exercise was not shown to be more effective for the treatment of acute low back pain than advice and exercise alone when assessed using the Oswestry low back pain disability questionnaire, visual analogue pain scales or the Short-form 36 questionnaire immediately post-intervention and at one month and six months following intervention.
To summarise, the major clinical findings of this thesis are, that DTPs identified using SCS procedures in the lower back are distinctive from contralateral non-tender control points; SCS treatment does appear to cause a significant immediate reduction in tenderness at DTPs in the low back but this does not appear to be maintained between 24 and 72 hours following treatment; no significant improvements were found in measures of pain and disability for participants with ALBP after 2 weeks and at one-month and six-month follow-ups with the addition of SCS treatment to exercise therapy. These findings represent an original and significant contribution to the area of manual therapy for treatment of non-specific low back pain. Further research directions for the SCS paradigm of assessment and treatment are identified in the thesis.