Figure 7. Examination of non-crossbridge component.

A, effects of BTS on tension contribution by the two components. Bars represent the mean (±s.e.m.) BTS/control tension ratios from 4 fibre bundles. The ratio for isometric tetanic tension P₀ is shown by the open column. The ratios for P_L and P₃* are from analyses of the peak tension versus velocity data and amplitude of fast (A_f) and amplitude of slow plus P₃ (labelled NC) from analysis of the tension relaxation. Note that, with either analysis, the non-crossbridge contribution (hatched columns) is much less depressed than the crossbridge contribution (filled columns). B, absence of residual force enhancement after stretch in a slow muscle. Tension response (upper trace) to a ramp stretch at 5 L₀ s⁻¹ (lower trace) on a small bundle of soleus muscle fibres. Also shown are the isometric tetanic contractions at L₀ and the extended length (L₀+ 5%). The inset shows the tension response to the stretch at a higher resolution. Note that the residual tension (P₃) and the tension rise after the P₂ transition are absent.