Emotionally affective imaginations can influence the Adaptive Force (AF) in healthy participants as was recently shown in an exploratory study. The AF describes the neuromuscular holding capacity in reaction to an increasing external force, which was suggested to be especially vulnerable for interfering inputs. The present study investigated the influence of pleasant and unpleasant food imaginations on the manually assessed AF of elbow and hip flexors objectified by a handheld device in 12 healthy young women in an improved design. Baseline measurements, randomization of imagination tasks and single-blinding were implemented. The maximal isometric Adaptive Force was significantly reduced during unpleasant vs. pleasant imaginations and baseline (p < 0.001, dz = 0.98 to 1.61). During unpleasant imaginations muscle lengthening started at 59.00 ± 22.50% of the maximal AF, which was reached during eccentric muscle action. For baseline measurements and pleasant imaginations, this ratio amounted ~97.90 ± 5.00% for both muscles, indicating that the participant was able to maintain the isometric position during the entire external force increase. For those stable adaptations, oscillations arose in force signal at a level of ~72.26 ± 12.89% of AFmax, whereby they occurred under isometric conditions. For unpleasant imaginations, the onset of oscillation was at a force of 84.28 ± 14.03% of AFmax, which in most cases was after the muscle started to lengthen.In conclusion, healthy participants showed an impaired holding function triggered by unpleasant imaginations, which are assumed to be related to negative emotions. This muscular instability is suggested to lead to joint destabilization which can result in musculoskeletal complaints. Therefore, the findings might support the understanding of the causal chain of linked musculoskeletal pain and mental stress. A case example (current stress vs. positive imaginations) will be presented, underpinning the hypothesis this approach might support psychomotor diagnostics and therapeutics.