2012 Annual Conference

Smith, Ryan

Army-Baylor University, San Antonio, Texas

To identify predicitive factors from a routine clinical examination and clinical improvement one week after Trigger Point Dry Needling (TDN) in patients with low back pain (LBP).

68 individuals: 39 men, 29 women, age= 41.5+ 9.4 years, body mass index= 28.9+ 5.0 kg/m² , months since initial LBP onset= 59.6+83.8 months. 

Consenting participants underwent a standard LBP history and physical examination.  Potential prognostic factors were collected from questionnaires, patient history and baseline physical examination tests.  Treatment consisted of TDN to the lumbar multifidus (LM) muscles bilaterally at L3/L4, L4/L5, and L5/S1.  Patients were followed up one week later and reassessed using the Oswestry Disability Index (ODI).  Clinical improvement was based on a  % improvement in the ODI. 

Twenty-six potential prognostic factors were selected based on theoretical potential relationship with clinical improvement following TDN.  The bivariate association between the factors and clinical improvement was first assessed using correlation analysis.  Factors significantly related to % improvement in the ODI (α = 0.15) were then entered into a forward linear regression model to determine the most parsimonious set of predictive factors.

Nine factors were significantly correlated with % improvement in the ODI. Positive correlations were found for pain with contralateral arm lift (r_pb = 0.31), back pain with hip flexion (r_pb = 0.23), and belief in acupuncture (ρ = 0.22).  Negative correlations were found for aggravation with standing (r_pb = -0.27), presence of leg pain (r_pb = -0.29), number of prior episodes (ρ = -0.21).  Linear regression produced a model with two variables that were most predictive of clinical improvement: pain with contralateral arm lift and no aggravation with standing, resulting in an adjusted R² of 0.16, p= 0.002.  

The factors that best predicted clinical improvement after TDN in this study (pain with contralateral arm lift and no aggravation with standing) suggest a relationship between pain with activation of the LM muscle and clinical improvement with TDN to the LM.  All of the predictive variables together suggest that patients with LBP that do not report leg pain or depression and have pain with LM muscle contraction may be the best candidates for TDN.

The results of this study can help guide future studies and clinicians to identify patients that will benefit from TDN.  Better matching patients with the proper treatments should decrease healthcare costs and expedite return to duty for patients with LBP.