Measurement of recovery of function following whole muscle transfer, myoblast transfer, and gene therapy.

For a skeletal muscle tissue engineer, the most important issue following an experimental intervention is the evaluation of the recovery of the functional capabilities of the tissue, relative to those of the control tissue. Whether investigators perform whole muscle transfers with spontaneous (1) or surgical (2) vascular and nerve repair, myoblast transfers (3), or manipulations of muscle-specific genes (4,5), the question remains the same: Has the intervention impaired, maintained, or enhanced the functional capabilities of the skeletal muscles involved? In each case, determining structure-function relationships is of vital importance because structure-function relationships are frequently disrupted following an intervention, so that muscle mass and total muscle fiber cross-sectional area (CSA) are not different from control values, but function is impaired, or both are impaired, but with different magnitudes of impairment.