Mirthful Laughter and Muscle Soreness / Pain
Condition: Pain
MeSH terms: Myalgia
Study type: Interventional

Summary: 
      The purpose of this study is first to investigate the effect of a controlled intervention
      with a comedy video on pain tolerance in a social setting while quantitatively measuring
      laughter in a young healthy population experiencing delayed onset muscle soreness. The comedy
      intervention will be compared to a control of watching a documentary. The second aim is to
      examine to what extent various methods of eliciting pain would cause physiological responses
      that confound the interpretation of a pain stimulus.
    

Detailed description: 
      Chronic pain affects 116 million people, that is more than the total affected by
      cardiovascular disease, cancer, and diabetes combined. Chronic pain has at least as large of
      a negative impact on quality of life as any other chronic disorder, and in the United States
      alone, the cost of chronic pain exceeds $635 billion per year. Interventions that effectively
      manage chronic pain are becoming increasingly important as the elderly population, who often
      suffer from osteoarthritis and low back pain, rises. Pain sensitivity and tolerance are
      impacted by a variety of affective factors. The laughter therapy is one of the most discussed
      and often controversial strategies for the management of pain. There are some preliminary
      uncontrolled studies reporting that pain tolerance is increased acutely with humor and
      laughter. Accordingly, the primary aim of the present study is to investigate the effect of a
      highly controlled intervention with a comedy video on pain tolerance and compare it to a
      control of watching a documentary video. Quantitatively measuring laughter with a chest
      stress-strain gauge during the interventions will allow the investigators to look for a
      possible dose response relationship. The investigators will use the pain and soreness felt
      from delayed onset muscle soreness (DOMS) in healthy subjects to simulate the condition of
      individuals suffering from chronic pain. This study will serve as a precursor to eventual
      studies specifically on individuals with chronic pain. If it can be proven that pain
      tolerance is increased in a healthy population than it is possible the intervention will have
      a greater affect in the chronic pain population.

      Using healthy subjects with delayed onset muscle soreness allows the investigators to easily
      recruit and control for other diseases or disorders that may accompany a chronic pain
      individual.

      There have been a number of different techniques used to assess pain tolerance. The modes of
      stimulating pain used in previous studies of laughter and humor on pain tolerance remain
      controversial. These studies utilized the cold pressor test and the inflation of a blood
      pressure cuff to elicit pain. Both of these methods are known to elicit marked cardiovascular
      responses along with the pain responses. An important part of the pain regulatory process in
      humans is that there is a functional interaction between the cardiovascular and pain
      regulatory systems. The brain regions underlying control of the cardiovascular system are
      known to overlap substantially with those that contribute to anti-nociception. Accordingly,
      it is difficult to determine how much of the pain tolerance is affected by cardiovascular
      reflexes. Thus, the secondary aim of the present study is to test how much cardiovascular
      responses will be elicited by a variety of methods of eliciting pain (pumping up a blood
      pressure cuff, the cold pressor test, and the application of blunt force on muscles).

      The application of blunt force will be used to elicit pain without causing a systemic
      response involving cardiovascular reflexes which is seen in the cold pressor and inflation of
      a blood pressure cuff. The investigators believe these vast cardiovascular responses may
      cause pain tolerance to not be truly measured. It has been inferred that blunt force applied
      within a few seconds to a local, specific spot on the quadriceps will not stimulate a
      systemic and cardiovascular response and thus the pain tolerance measurement will be more
      accurate if independent of cardiovascular responses. Pressure and force application is widely
      used as an experimental pain stimulus, but it has not been utilized in the context of
      laughter and pain.
    

Intervention name(s): 30 Minute Comedy Video; 30 Minute Documentary Video
Intervention type(s): Other; Other
Intervention description(s): The intervention is a 30 minute video of a comedy; The intervention is a 30 minute video of an uninteresting documentary
Intervention model: Single Group Assignment
Intervention model description: The main study was conducted using a randomized controlled cross-over approach.
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: delayed onset muscle soreness; laughter