History
The first and most crucial step is obtaining comprehensive information on the onset, timing, and frequency of symptoms; any associated symptoms; and alleviating and exacerbating factors. More detailed information about the culprit activity or technique problem is also key. Systemic symptoms should be elicited, if present. Other hallmark symptoms may include a history of popping, clicking, rubbing, erythema, or vascular phenomena. [2] When interviewing an athlete, specific attention must be paid to training details, equipment fit, and technique.
Physical
The examination should begin with the basics of inspection, palpation, and passive and active range of motion (ROM). Tenderness and guarding are often present. Crepitus, either painful or painless, is often found during the ROM examination. Obvious erythema, swelling, and anatomic derangement raise the possibility of an acute injury or infection, as well as the presence of an inflammatory disease. [22] For physical findings associated with specific injuries, refer to the specific articles in the Differentials section.
Causes
The most important factor leading to overuse injury is repetitive activity, although the specific type of force leads to different outcomes. [23]
One group of authors accurately described the issue as "a culprit and a victim," in which the victim is the injured tissue, and the culprit is the true biomechanical cause. All too frequently, physicians focus on the victim tissue and not on the culprit.
Repetition is part of the definition of overuse injury. The concept is that overuse injury is associated with repeated challenge without sufficient recovery time.
Cycles and fundamental cycles are terms used to describe activities repeated at work. A cycle is a large-scale activity that is repeated throughout the day. A fundamental cycle is a small component of a cycle that may be repeated several times during the performance of a cycle. If a job has cycles that are repeated many times a day, the job is designated as repetitive. The tendency in industry to specialize labor for the sake of efficiency and better productivity has resulted in fewer different tasks per job. These tasks are repeated frequently, and this repetition is believed to be a contributing factor to the increase of overuse injury claims. Repetitiveness and force exerted are features of a task that increase the risk of sustaining an overuse injury.
However, there have been studies that dispute this theory, finding that cycle times and repetitive motions do not specifically lead to overuse injury in the upper extremity. Most articles in the literature, though, implicate repetitive motions as possible causes of injury,
Vibration, especially over long periods, has long been shown to be a factor in increasing the risk of many injuries (eg, lower back pain, intervertebral disk injury, wrist injury). One systematic review estimated that workers with hand-arm vibration exposure had a 4-5 times greater likelihood of developing neurologic and vascular diseases (ie, carpal tunnel syndrome, Raynaud phenomenon). [24]
The greater the forces involved in an activity, the greater the chance of developing an overuse injury. [25]
Malpositioning limbs away from their neutral position increases the risk for overuse injury. Multiple articles in dental and surgical literature emphasize this point. Ergonomics is the field that focuses primarily on designing devices that lend themselves to good positioning. A massive increase has occurred in the amount of ergonomically designed work equipment, especially keyboards and mouses. The literature remains divided on their effectiveness in decreasing injuries.
A literature review found a moderate association between hand-arm symptoms and increasing duration of mouse use. [26, 27] There was a weaker association between neck-arm symptoms and mouse use. Nevertheless, prolonged computer and mouse use does not typically result in chronic neck and shoulder pain. [28] However, certain psychosocial factors may be predictive of chronic pain.
A literature review by Arnold et al concerning skeletally immature athletes with overuse physeal injuries found that risk factors for such trauma include periods of accelerated growth, body size, previous injury, chronologic age, and training volume. [14]
A prospective study by Jayanthi et al indicated that child athletes with a high degree of sports specialization are more likely to suffer injury, including overuse injury, than are less specialized athletes. The investigators, who looked at athletes aged 7-18 years, reported this outcome to be more likely in females. The study also found that those young athletes for whom the number of hours spent training each week exceeds their age are at greater risk for overuse injuries, as are those who spend more than twice as many hours per week in organized sports than in free play. [29]
A study by De Bleecker et al indicated that in athletes competing in sports that require repeated use of landing maneuvers, knee overuse injuries are more likely in those whose landing is characterized, at initial contact, by greater hip adduction and increased knee internal rotation, as well as by greater peak knee external rotation and reduced ankle dorsiflexion at peak vertical ground reaction force. Moreover, overuse injuries of the groin were found to correlate with greater range of motion in the pelvic and hip frontal and transversal planes. [30]
