Pain is difficult to assess because it is a symptom rather than a sign. Quantification of pain is very subjective since it is a sensory phenomenon with an affective-motivational dimension (Melzack 1983).
The sensory component relates to what the individual feels. In order to determine whether your treatments are helping the injured athlete, an attempt to quantify the pain is necessary.
Pain measurement should be reliable and valid. To assess the intensity of pain, you can use a simple pain scale, for instance by asking the individual to rate the pain from 0 = no pain to 10 = worst pain ever. This type of pain assessment, the verbal pain rating, is quick and simple but becomes less effective when the athlete is asked for a score several times throughout the evaluation and treatment. For example, the athlete will remember reporting a “5” before the treatment and subconsciously use that figure as a reference for reporting his or her score after the treatment is over.
A visual analog scale (VAS) (figure 4.1) has no demarcations, so the patient cannot use a previous score as a reference point. The VAS uses a 10-cm-length line with the words “no pain” on one end and “unbearable pain” on the other end. The upper end should imply postsurgical or excruciating pain. The clinician measures the horizontal distance from the left to the athlete’s mark of the extent of his or her pain in centimeters for the pain score. Some clinicians have used a continuum of descriptors along the visual analogue scale to help better describe the degree of pain. These descriptors are “dull ache,” “slight pain,” “more than slight pain,” “painful,” and “very painful” (Denegar and Perrin, 1992).
More complex assessments invole pain charts (figure 4.2) or a comprehensive questionnaire such as the Pain Disability Index to assess the impact of pain on function (Pollard 1984). An example of the Oswestry Pain and Disability Index is presented in figure 7.2 on page 98. These assessments have been validated and can help categorize how pain is contributing to the individual’s disability. The more simple scales can be used to quickly assess recovery from injury. The more comprehensive evaluations are more time-consuming but yield valuable insight about persistent and chronic pain. These instruments can also be used to study the effects of therapeutic interventions.