The influence of emotionally affective imaginations on the Adaptive Force (AF) in healthy participants was recently shown in an exploratory study. The AF describes the neuromuscular capacity to adapt to increasing forces, which was suggested to be especially vulnerable for interfering inputs. This study investigated the influence of pleasant and unpleasant food imaginations on the manually assessed AF of elbow/hip flexors objectified by a handheld device in 12 healthy women in an improved design. The maximal isometric AF was significantly reduced during unpleasant vs. pleasant imaginations and baseline (p < 0.001, dz=0.98–1.61). During unpleasant imaginations muscle lengthening started at 59.00 ± 22.50 % of maximal AF, in contrast to baseline and pleasant imaginations during which the isometric position could be maintained mostly during the entire force increase up to ~97.90 ± 5.00 % of maximal AF. Healthy participants showed an immediately impaired holding function triggered by unpleasant imaginations presumably related to negative emotions. Hence, the AF seems to be suitable to test instantaneously the effect of emotions on motor function. Since musculoskeletal complaints can result from muscular instability, the findings provide insights into the understanding of the causal chain of linked musculoskeletal pain and mental stress. A described case example (current stress vs. positive imaginations) underpins the hypothesis this approach might support psychomotor diagnostics and therapeutics.