Improved contraction of the transversus abdominis immediately following spinal manipulation: A case study using real-time ultrasound imaging

Abstract

The authors encountered a clinical dilemma when attempting to apply a clinical prediction rule for manipulation (Flynn et al., 2002; Childs et al., 2004) to a patient with a history and physical examination consistent with clinical lumbar instability (Hicks et al., 2005). Although the patient met four of five criteria predicting short-term success with manipulation, the presence of symptoms suggestive of underlying clinical instability remains a relative contraindication to thrust manipulation (Greenman, 1996; Maitland, 2001). Could the application of both manipulation and stabilization be logically justified in this patient? Despite the widespread use of spinal manipulation, the biological mechanisms by which it produces a beneficial effect in certain patients are not fully understood (Pickar, 2002). There is evidence which supports a reflexogenic effect from manipulation in the paraspinal muscles as one possible mechanism (Herzog et al., 1995, 1999; Lehman et al., 2001; Pickar, 2002). Specifically, several researchers have identified altered motor neuron pool excitability following spinal manipulation (Murphy et al., 1995; Floman et al., 1997; Herzog et al., 1999; Dishman and Bulbulian, 2000). The effect on neural pathways associated with manipulation has been suggested as one possible mechanism that may improve muscle performance (Pickar, 2002) and patient symptoms.