Behavioral and subjective data.

A) Force profile (average of 50 trials) of the baseline (dashed lines) and final (solid lines) sessions in one subject of the experimental group (red lines) and one subject of the control group (green lines). B) Normalized force peak decreases in the experimental group (red line) from baseline to final session, whereas it remains stable in the control group (green line). Moreover, the two groups have nearly different values in the final session. C) Also the percentage of strong pressures decreases in the experimental group (red line) from baseline to final session, whereas it remains stable in the control group (green line). D) Scores of expectation of change in performance. The experimental group (red bar) expected a more negative change of performance than the control group (green bar). E) Judgments of treatment efficacy. The experimental group (red bar) has higher score than the control group (green bar). F) Subjective perception of force. In general, the experimental group (red line) felt weaker than the control group (green line). G) Sense of effort [22] was overall higher in the final than in the baseline session. All the values are expressed as mean ± SE. **p < 0.010, *p < 0.050, ~ p = 0.056.