Documentation of myofascial trigger points.

Two basic diagnostic features of myofascial trigger points (TPs), namely, local tenderness and alteration of tissue consistency (such as in taut bands, muscle spasm), can be documented quantitatively by simple hand-held instruments. A pressure threshold meter (algometer) assists in location of TPs and their relative sensitivity. A side-to-side difference exceeding 2kg in comparison with normal values indicates pathologic tenderness. The effect of treatment can be quantified. Pressure tolerance, measured over normal muscles and shin bones, expresses pain sensitivity. Myopathy is suspected if muscle tolerance drops below bone tolerance. Tissue compliance measurement documents objectively and quantitatively alteration in soft tissue consistency. Muscle spasm, tension, spasticity, taut bands, scar tissues, or fibrositic nodules can be documented. The universal clinical dynamometer is used as part of a physical examination to quantify weakness. Thermography (heat imaging) demonstrates discoid shaped hot spots over TPs. Muscle activity, spasm, or contraction is visualized as increased heat emission in the shape of the active muscle.