Barry Goldberg

Deficits in Neuromuscular Control of the Trunk Predict Knee Injury Risk A Prospective Biomechanical-Epidemiologic Study

Background Female athletes are at significantly greater risk of anterior cruciate ligament (ACL) injury than male athletes in the same high-risk sports. Decreased trunk (core) neuromuscular control may compromise dynamic knee stability. Hypotheses (1) Increased trunk displacement after sudden force release would be associated with increased knee injury risk; (2) coronal (lateral), not sagittal, plane displacement would be the strongest predictor of knee ligament injury; (3) logistic regression of factors related to core stability would accurately predict knee, ligament, and ACL injury risk; and (4) the predictive value of these models would differ between genders. Study Design Cohort study (prognosis); Level of evidence, 2. Methods In this study, 277 collegiate athletes (140 female and 137 male) were prospectively tested for trunk displacement after a sudden force release. Analysis of variance and multivariate logistic regression identified predictors of risk in athletes who sustained knee injury. Results Twenty-five athletes (11 female and 14 male) sustained knee injuries over a 3-year period. Trunk displacement was greater in athletes with knee, ligament, and ACL injuries than in uninjured athletes (P < .05). Lateral displacement was the strongest predictor of ligament injury (P = .009). A logistic regression model, consisting of trunk displacements, proprioception, and history of low back pain, predicted knee ligament injury with 91% sensitivity and 68% specificity (P = .001). This model predicted knee, ligament, and ACL injury risk in female athletes with 84%, 89%, and 91% accuracy, but only history of low back pain was a significant predictor of knee ligament injury risk in male athletes. Conclusions Factors related to core stability predicted risk of athletic knee, ligament, and ACL injuries with high sensitivity and moderate specificity in female, but not male, athletes.

The Effects of Core Proprioception on Knee Injury A Prospective Biomechanical-Epidemiological Study

Background In sports involving pivoting and landing, female athletes suffer knee injury at a greater rate than male athletes. Hypotheses Proprioceptive deficits in control of the bodys core may affect dynamic stability of the knee. Female, but not male, athletes who suffered a knee injury during a 3-year follow-up period would demonstrate decreased core proprioception at baseline testing as compared with uninjured athletes. Study Design Cohort study (prognosis); Level of evidence, 2. Methods Study subjects were 277 collegiate athletes (140 female, 137 male) who were prospectively tested for core proprioception by active and passive proprioceptive repositioning. Athletes were monitored for injury for 3 years. An ANOVA and multivariate logistic regression were used to test whether core proprioception was related to knee injuries in athletes. Results Twenty-five athletes sustained knee injuries (11 women, 14 men). Deficits in active proprioceptive repositioning were observed in women with knee injuries (2.2°) and ligament/meniscal injuries (2.4°) compared with uninjured women (1.5°, P ≤ .05). There were no differences in average active proprioceptive repositioning error between injured men and uninjured men (P ≥ .05). Uninjured women demonstrated significantly less average error in active proprioceptive repositioning than uninjured men (1.5° vs 1.7°, P ≤ .05). For each degree increase in average active proprioceptive repositioning error, a 2.9-fold increase in the odds ratio of knee injury was observed, and a 3.3-fold increase in odds ratio of ligament/meniscal injury was observed (P ≤ .01). Active proprioceptive repositioning predicted knee injury status with 90% sensitivity and 56% specificity in female athletes. Conclusions Impaired core proprioception, measured by active proprioceptive repositioning of the trunk, predicted knee injury risk in female, but not male, athletes.

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.

Changes in body composition after a 12-wk aerobic exercise program in obese boys

Previous studies have shown that vigorous aerobic training programs for obese children result in minimal weight changes, and concluded that they may not be beneficial. Weight change alone may not detect important beneficial changes in body composition associated with vigorous training in these children.
 Fifteen obese boys (aged 9–12 yr, body mass index (BMI) 31.8±6.5, average percent body fat (%BF) 41±4.2) underwent a supervised aerobic and resistance training program (12 wk, 2 days/wk for 30 min/session), to investigate the effects on weight and body composition.
 After the 3‐month training period, weight loss averaged only 1.5±1.0 kg (not significant), but total body fat decreased by 4.1±1.8 kg (p<0.05) and fat‐free mass (FFM) increased by 2.6±1.1 kg (p<0.05) based on hydrostatic weighing. As a result, %BF fell by 10% (p<0.01). There was a 5.8±2.8 mL/kg/min (p<0.05) increase in peak volume of oxygen uptake (VO2), along with a 248±120 kcal/d (p<0.05) increase in resting energy expenditure (REE). Activity questionnaires showed a significant increase in high intensity recreational activities (6.5±1.5 vs 3.5±0.5 h physical activity/wk; p<0.01) in the home and a significant decrease in low intensity activities (7±2.0 vs 12±3.5 h TV viewing/wk; p<0.01).
 Conclusions: Vigorous supervised aerobic training in obese boys has beneficial effects on body composition, fitness and leisure time activities that are not apparent by measurement of changes in body weight alone.

Elbow Injuries in Young Baseball Players

The demands that throwing places on the vulnerable immature elbow frequently produce multiple injuries. Significant clues in the history include persistent medial elbow soreness, stiffness, and discomfort that lead to poor performance. Diagnosis involves identifying the injury sites by palpation and x-rays that pinpoint growth-plate separation or osteochondral changes. Nonoperative treatment, which can proceed if growth-plate separation at the medial apophysis is less than 3 mm, involves stretching, strengthening, sport-specific activities, and interval throwing. Prevention includes conditioning, limiting the number of pitches, and using age guidelines for learning new pitches.

Children's Sports Injuries: Are They Avoidable?

In this study of 51 childrens sports injuries, 21 injuries occurred in a nonorganized setting and 32 were deemed avoidable. Preventive measures are discussed.

Nontraumatic hip pain in active children : a critical differential

A case report of an 8-year-old baseball player who was diagnosed with Legg-Calvé-Perthes (LCP) disease gives an opportunity to consider the many nontraumatic causes of hip pain. Possibilities include slipped capital femoral epiphysis, septic arthritis, transient synovitis, juvenile rheumatoid arthritis, and bone tumor. Radiographs and bone scans are used to document and stage LCP, and to evaluate the effectiveness of treatment. Though the aggressiveness of treatment depends on the disease stage, the treatment of choice is generally nonsurgical containment of the femoral epiphysis with a cast or orthosis.