Lumbar position sense and the risk of low back injuries in college athletes: a prospective cohort study.

BACKGROUND: Impaired proprioception in the lumbar spine has often been reported in people with low back pain. However, no prospective studies exist to assert the cause and effect of this association. We hypothesized that athletes with a history of low back injury (LBI) would demonstrate poorer lumbar position sense (PS) than athletes without a history of LBI, and that this deficit would be a risk factor for future LBI. METHODS: This was a prospective cohort study with 2-3 year follow-up. Lumbar spine PS in the transverse plane was evaluated in 292 athletes using three tests: 1) passive and 2) active trunk repositioning, and 3) motion perception threshold. Mean absolute (accuracy) and variable (precision) errors were computed. RESULTS: There were no significant differences in the repositioning errors or motion perception threshold between athletes with and without a history of LBI or between those who did and did not get injured during the follow-up. Active trunk repositioning resulted in smaller errors than passive repositioning (1.6 degrees +/- 0.8 degrees ) versus 2.1 degrees +/- 1.0 degrees ) and 1.7 degrees +/- 0.8 degrees ) versus 2.3 degrees +/- 1.1 degrees ) for the absolute and relative errors, respectively). CONCLUSION: Poor trunk PS in transverse plane is not associated with LBI in athletes, nor does it appear that poor trunk PS predisposes athletes to LBI.

Back pain in athletes.

The athlete with back pain presents a clinical challenge. Self-limited symptoms must be distinguished from persistent or recurrent symptoms associated with identifiable pathology. Athletes involved in impact sports appear to have risk factors for specific spinal pathologies that correlate with the loading and repetition demands of specific activities. For example, elite athletes who participate in longer and more intense training have higher incidence rates of degenerative disk disease and spondylolysis than athletes who do not. However, data suggest that the recreational athlete may be protected from lumbar injury with physical conditioning. Treatment of athletes with acute or chronic back pain usually is nonsurgical, and symptoms generally are self-limited. However, a systematic approach to the athlete with back pain, involving a thorough history and physical examination, pertinent imaging, and treatment algorithms designed for specific diagnoses, can facilitate symptomatic improvement and return to play. There are no reliable studies examining the long-term consequences of athletic activity on the lumbar spine.

Avoidance and management of intra-articular complications of anterior cruciate ligament reconstruction.

An estimated 70,000 to 100,000 anterior cruciate ligament reconstructions are performed each year in the United States. With the increasing number of anterior cruciate ligament surgeries being performed, a concomitant increase in intraoperative complications can be expected. Complications include those associated with tunnel placement, notchplasty, graft fixation and advancement, suture laceration, graft laceration, guidewire insertion and removal, intra-articular hardware, posterior cruciate ligament laceration, compartment syndrome, and vascular injury.

Delayed trunk muscle reflex responses increase the risk of low back injuries.

STUDY DESIGN: Prospective observational study with a 2- to 3-year follow-up. OBJECTIVES: To determine whether delayed muscle reflex response to sudden trunk loading is a result of or a risk factor for sustaining a low back injury (LBI). SUMMARY OF BACKGROUND DATA: Differences in motor control have been identified in individuals with chronic low back pain and in athletes with a history of LBI when compared with controls. However, it is not known whether these changes are a risk for or a result of LBI. METHODS: Muscle reflex latencies in response to a quick force release in trunk flexion, extension, and lateral bending were measured in 303 college athletes. Information was also obtained regarding their personal data, athletic experience, and history of LBI. The data were entered into a binary logistic regression model to identify the predictors of future LBI. RESULTS.: A total of 292 athletes were used for the final analysis (148 females and 144 males). During the follow-up period, 31 (11%) athletes sustained an LBI. The regression model, consisting of history of LBI, body weight, and the latency of muscles shutting off during flexion and lateral bending load releases, predicted correctly 74% of LBI outcomes. The odds of sustaining LBI increased 2.8-fold when a history of LBI was present and increased by 3% with each millisecond of abdominal muscle shut-off latency. On average, this latency was 14 milliseconds longer for athletes who sustained LBI in comparison to athletes who did not sustain LBI (77 [36] vs. 63 [31]). There were no significant changes in any of the muscle response latencies on retest following the injury. CONCLUSIONS: The delayed muscle reflex response significantly increases the odds of sustaining an LBI. These delayed latencies appear to be a preexisting risk factor and not the effect of an LBI.

Neuromuscular function in athletes following recovery from a recent acute low back injury.

STUDY DESIGN: Observational case control design. OBJECTIVES: To examine muscle response to sudden trunk loading in athletes with and without a recent history of acute low back injury (LBI). BACKGROUND: Impaired neuromuscular function is associated with chronic low back pain. This study examined whether such impairment persists after recovery from an acute LBI. METHODS AND MEASURES: Seventeen athletes who had a recent history of acute LBI and 17 matched healthy controls were tested. At the time of testing (mean = 56 days postinjury, range = 7-120 days postinjury), all athletes were symptom free and had returned to regular competition. Subjects performed isometric exertions in trunk flexion, extension, and left and right lateral bending against a trunk restraining cable. Upon reaching the target isometric force, the cable was released to impose sudden loading on the lumbar spine. Surface EMG signals from 12 major trunk muscles were recorded. The shut-off and switch-on latencies and number of muscles responding to sudden loading were compared between the 2 groups. RESULTS: In all 4 testing directions, the athletes with a recent history of acute LBI shut off significantly fewer muscles and did so with delayed latency. On average, the injured subjects shut off 4.0 out of 6.0 (SD = 1.3) muscles compared to 4.6 out of 6.0 (SD = 1.3) muscles in the control group. The average muscle shut-off latency was 71 (SD = 31) milliseconds for the injured and 50 (SD = 21) milliseconds for the control subjects. No differences were found in number or latency of muscles switching on. CONCLUSIONS: These objective measures of neuromuscular function indicated an altered muscle response pattern to sudden trunk loading in athletes following their clinical recovery from a recent acute LBI.