The Influence of Baseline Sensitivity and Expectation on Exercise-induced Hypoalgesia in Young Healthy Adults

実験的：submaximal isometric exercise.

submaximal isometric exercise will be performed.

他の：Submaximal isometric exercise

The exercise is a submaximal isometric contraction

介入なし：Quiet rest.

Subject will rest in seating position for a period that mimics the exercise time.

The change from baseline of pain ratings during temporal summation of pressure pain assessment

Temporal summation is the increase of pain over time caused by a constant or repetitive noxious stimulus. Pain reports will be obtained during the application of constant mechanical stimulus with various intensities. Subjects will be asked to rate the pain using a numerical pain rating scale that ranges from 0 (no pain) to 10 (worst pain). Pain ratings will be obtained at the beginning, during, and at the end of the test while a noxious stimulus is applied to the index finger. The change of pain ratings relative to baseline after exercise or quiet rest will be assessed.

Expectation

Subjects will be asked about their expectation of whether exercise will increase, decrease, or have no effect on the pain.

State version of the State-Trait Anxiety Inventory (STAI)

A 20-item questionnaire from state-trait anxiety inventory that evaluates different feelings the subject may or may not have at the moment. The score of the questionnaire ranges from 0 to 80. Higher scores indicate greater state anxiety levels.

Trait version of the State-Trait Anxiety Inventory (STAI)

A 20-item questionnaire from state-trait anxiety inventory that evaluates how the subject feels in general and not restricted to the current moment. The score of the questionnaire ranges from 0 to 80. Higher scores indicate greater trait anxiety levels.

Pain catastrophizing scale

A 13-item scale that evaluates if the subject has an exaggerated negative mental set towards pain. It has 3 sub-scales which are magnification, rumination, and helplessness. The scores of the sub-scales are summed to get the total score. The total score ranges from 0 to 52. Greater scores indicate greater catastrophizing thinking.

Situational pain catastrophizing scale

A 6-item questionnaire that explores the negative mental set or catastrophizing thinking in reference to a particular experimental pain experience (i.e., temporal summation protocol). The score ranges from 0 to 24 with higher scores indicating greater situational catastrophizing.

Physical activity assessment using International physical activity questionnaire.

International physical activity questionnaire (IPAQ) will be used to assess physical activity in the past week. IPAQ evaluates physical activity not only related to leisure time but also related to other domains such as transportation, work, gardening or house related physical activities. The questionnaire has been shown to be reliable and valid. The time spent in moderate to vigorous physical activity (minutes/ week) from every domain will be summed with 0 indicating no time (minutes / week) spent moderate to vigorous activities and higher values indicate greater time spent in moderate to vigorous physical activity.

Muscle mass assessment using Dual-energy x-ray absorptiometry.

Dual-energy x-ray absorptiometry (General Electric Healthcare, Madison, Wisconsin) is an x-ray scan that is used to assess muscle mass.

Fat mass assessment using Dual-energy x-ray absorptiometry.

Dual-energy x-ray absorptiometry (General Electric Healthcare, Madison, Wisconsin) is an x-ray scan that is used to assess fat mass.