Gain of postural responses increases in response to real and anticipated pain

摘要: This study tested two contrasting theories of adaptation postural control to pain. One proposes alteration the strategy including inhibition muscles that produce painful movement; another amplification adjustment recruit strategies normally reserved for higher load. aimed determine which these alternatives best explains pain-related hip muscle activity associated with stepping down from steps increasing height load was evaluated electromyography (fine-wire and surface electrodes) as ten males stepped (i.e. load). In one set trials, participants a low step (5 cm) pain induced by noxious electrical stimulation over sacrum triggered foot contact force plate or anticipated. Changes in EMG amplitude onset timing were compared between conditions. Hip activation earlier larger when steps. Although ground reaction forces (one determinants joint load) unchanged before, during after pain, trials real anticipated accompanied indistinguishable (EMG increased 9 17 % peak). These data support notion is augmented challenged real/anticipated stimulation. Muscle greater than required task likely create unnecessary loading. could have long-term consequences if maintained.