Years of running experience influences stride-to-stride fluctuations and adaptive response during step frequency perturbations in healthy distance runners.

RESEARCH QUESTION: The current study investigated stride-to-stride fluctuations of step rate and contact time in response to enforced step frequency perturbations as well as adaptation and de-adaptation behavior. METHODS: Forty distance runners ran at a self-selected speed and were asked to match five different enforced step frequencies (150, 160, 170, 180, and 190 beats per min). The influence of experience was explored, because running is a skill that presumably gets better with practice, and increased years of running experience is protective against injury. Detrended fluctuation analysis was used to determine the strength of long-range correlations in gait fluctuations at baseline, during the perturbation, and post-perturbation. Adaptive response was measured by the ability to match, rate of matching, and aftereffect of step frequency perturbations. RESULTS: The structure of stride-to-stride fluctuations for step rate and contact time did not change during the perturbation or post-perturbation compared to baseline. However, fluctuations in step rate were affected by the level of perturbation. Runners with the most experience had a less persistent structural gait pattern for both step rate and contact time at baseline. Highly experienced runners also demonstrated the best adaptive response. They better matched the enforced step frequency, reached the enforced step frequency sooner, and returned to preferred step frequency more quickly following removal of the perturbation. SIGNIFICANCE: These findings indicate baseline locomotor flexibility may be beneficial to achieve task demands and return to a stable state once the task is complete. Increased locomotor flexibility may also be a contributing factor for reduced injury risk in experienced runners.

Experience does not influence injury-related joint kinematics and kinetics in distance runners.

PURPOSE: Increased running experience and more time spent running appears to be advantageous in reducing injury risk, although the reason behind this is unclear. It is plausible that more experience results in better running mechanics leading to less injuries. Running mechanics are often screened during clinical assessments and targeted for correction in gait retraining, particularly those thought to be global indicators of injury or those associated with elevated knee joint loading. Examining the biomechanics of runners who are less-injury prone can improve our understanding of the significance of faulty running mechanics in relation to injury. Our goal was to examine if running experience was correlated to differences in kinematics and kinetics associated with increased knee joint loading and running-related injury risk. METHODS: One hundred runners with varying experience ran on a pressure-sensing treadmill at a self-selected speed. Trunk and lower extremity kinematics, spatiotemporal measures, and ground reaction forces were collected. Multiple linear regression was used to assess the association between experience and three-dimensional hip kinematics, sagittal plane lower-extremity mechanics, and ground reaction forces while controlling for age and speed. RESULTS: Increased running experience was not significantly associated with running mechanics. Increased age was significantly associated with reduced peak knee flexion and increased contact time. Running speed influenced several spatiotemporal, kinematic, and kinetic variables. CONCLUSION: Increased years of running experience does not appear to significantly influence running mechanics. However, age and running speed do influence biomechanical variables associated with injury in distance runners. Thus, there may be factors, other than running mechanics, that contribute to less risk in more experienced runners.

Sonographically guided patellar tendon fenestration: prognostic value of preprocedure sonographic findings.

OBJECTIVES: The purpose of this study was to determine whether any sonographic features of jumper's knee can predict the outcome after sonographically guided percutaneous patellar tendon fenestration. METHODS: Patients were identified between July 2001 and March 2009 who had clinical and sonographic findings of jumper's knee, who had failed conservative treatment, and who had sonographically guided percutaneous fenestration of the patellar tendon. Pain levels were assessed before and 4 weeks after fenestration. Sonograms were retrospectively characterized with regard to echogenicity, size, definition, location, calcification, and hyperemia of the abnormal patellar tendon region. Sonographic findings before fenestration were correlated with clinical outcomes. RESULTS: A total of 45 patellar tendons (32 consecutive patients) were included in the study. The average prefenestration functional pain score was 3.6 (range, 2-5), and the average postprocedure functional pain score after 4 weeks was 1.4 (range, 0-5). The preprocedure sonographic finding that correlated with an improved clinical outcome after tendon fenestration was the presence of a well-defined tendon abnormality. No other sonographic findings were associated with the clinical outcome. After fenestration, 76% (34 of 45) showed clinical improvement; 24% (11 of 45) showed no change; and 0% (0 of 45) had worse symptoms at 4 weeks. CONCLUSIONS: The presence of a well-defined area of tendinosis on sonography was associated with clinical improvement after percutaneous sonographically guided fenestration of the patellar tendon. All tendons either improved (76%) or showed no change (24%) in the functional pain score at 4 weeks after fenestration.

Should ultrasound-guided needle fenestration be considered as a treatment option for recalcitrant patellar tendinopathy? A retrospective study of 47 cases.

OBJECTIVE: To report the retrospective results of ultrasound-guided needle fenestration for the treatment of recalcitrant patellar tendinopathy. DESIGN: Retrospective follow-up study. SETTING: University outpatient sports medicine clinic. PATIENTS: Forty-seven patellar tendons in 32 patients (26 men and 6 women; mean age, 26 years) with recalcitrant patellar tendinopathy. Diagnosis made via history, physical examination, and sonographic examination. INTERVENTION: Ultrasound-guided needle fenestration after failure of conservative management. MAIN OUTCOME MEASURES: Pre-treatment and 4-week clinical follow-up determination of functional activity score. Phone follow-up determination of best achievable level of activity and satisfaction score of the procedure. RESULTS: Average time to follow-up was 45 months. Seventy-two percent of patients reported excellent or good results when questioned regarding return to activity. Twenty-eight percent of patients were unable to return to their desired activity level. Six patients subsequently underwent surgical treatment. One athlete underwent surgery to repair a patellar tendon rupture that occurred 6 weeks after the procedure. Eighty-one percent of patients reported excellent or good satisfaction scores. CONCLUSIONS: Ultrasound-guided needle fenestration warrants further investigation for the treatment of recalcitrant patellar tendinopathy.

Sonographically guided percutaneous needle tenotomy for the treatment of chronic tendinosis.

OBJECTIVE: Initial reports have shown percutaneous sonographically guided needle tenotomy without corticosteroid injection to be effective for the treatment of tennis elbow. The purpose of this study was to determine the effectiveness of this procedure with various tendons throughout the body. METHODS: Fourteen tendons in 13 patients were identified as having a greater than 6-month history of clinical presentation consistent with tendinopathy that had failed treatment with physical therapy. All patients were treated with sonographically guided percutaneous tenotomy using a 22-gauge needle and a local anesthetic. A visual analog scale (VAS) pain score measurement was obtained before the procedure and at 4- and 12-week follow-up appointments. All complications were recorded. RESULTS: The 14 tendons in this study included patellar (5), Achilles (4), proximal gluteus medius (1), proximal iliotibial tract (1), proximal hamstring (1), common extensor elbow (1), and proximal rectus femoris (1). The composite VAS score was significantly lower at both 4 weeks (mean +/- SEM, 2.4 +/- 0.7) and 12 weeks (2.2 +/- 0.7) compared with the baseline (5.8 +/- 0.6; P < .001). No complications or morbidity occurred. CONCLUSIONS: Sonographically guided percutaneous tenotomy of tendinosis was effective in improving patient symptoms without complications. Further investigation with additional patients and comparisons to alternative treatments is needed to validate these preliminary results.

Management of clavicle fractures.

Fractures of the clavicle are relatively common injuries that can occur in patients of all ages. The history and physical examination remain the primary means of diagnosing this injury. Plain radiographs are helpful to confirm the diagnosis and to provide information regarding fracture classification, prognosis, and treatment options. The emphasis of this article is on the management of these injuries. Historically, only unstable distal clavicle fractures were treated operatively. However, recent well-conducted studies demonstrate that plate fixation of displaced midshaft clavicle fractures may result in improved functional outcome and a lower rate of malunion and non-union, compared with non-operative treatment. For clavicle fractures managed non-operatively, the sling-and-swathe or figure-of-eight splints remain appropriate options. Multiple factors should be considered when counseling an athlete on the appropriate time to return to sports participation after a clavicle fracture.

Ribose: more than a simple sugar?

This article reviews the current literature regarding the use of ribose as an ergogenic aid. Ribose manufacturers claim that it provides ergogenic benefit, but this has not been substantiated through scientific investigations. Data have shown promise that ribose supplementation leads to enhanced restoration of ATP levels following exercise, but this has seldom translated into increased athletic performance. However, as with many ergogenic aids, additional research is needed to clarify its value as a supplement.

Anabolic-androgenic steroids and testosterone precursors: ergogenic aids and sport.

This article reviews the recent literature on the use of anabolic-androgenic steroids (AAS) for performance enhancement. Recent studies utilizing supraphysiologic doses of testosterone have demonstrated increases in strength and improvements in body composition, despite earlier assertions by the medical community that steroids were ineffective as ergogenic aids. Although data that support the theory of conversion of prohormones, such as androstenediol, to testosterone in the body is available, support for testosterone precursors alone as ergogenic aids is lacking. Drug testing laboratories are utilizing new techniques that analyze carbon-13 levels of urinary steroids to detect exogenously administered steroids as well as the use of urine-manipulating agents. Investigations that seek to refute athletes' various claims for positive drug tests are ongoing. The recent discovery, characterization, and development of a urine test for tetra-hydro-gestrinone, a designer steroid, has brought the issue of performance enhancement once again into the public spotlight. Increasing attention is also being paid to the long-term effects of AAS abuse, as more authors characterize the changes to hematologic, hepatic, lipid, and hormone profiles as a result of years of steroid use. Although the understanding of AAS and testosterone precursors as performance-enhancing drugs continues to advance, there are likely to be more revelations as scientific investigations continue.

Quadriceps fat pad signal intensity and enlargement on MRI: prevalence and associated findings.

OBJECTIVE: The purpose of this investigation was to characterize the MRI appearance of the quadriceps fat pad and to correlate the findings with other knee abnormalities, anatomic measurements of the extensor mechanism, and findings from history and at physical examination. MATERIALS AND METHODS: Ninety-two consecutive knee MRI examinations from 84 patients were retrospectively reviewed by two musculoskeletal radiologists for quadriceps fat pad enlargement and signal intensity. Other data from the retrospective review included infrapatellar and prefemoral fat pad signal intensity, quadriceps and patellar tendon abnormalities, joint effusion, medial plica, chondromalacia, articular muscle thickness, and prepatellar edema. The patellar length, patellar articular length, patellar tendon length, and femoral sulcus angle were measured. MRI reports were reviewed for meniscal and ligament abnormalities. Clinical data were reviewed for findings of anterior knee pain in the history and at physical examination. The chi-square and Student's t tests were used to determine significant associations. RESULTS: Twelve percent (11/92) of MRI examinations showed quadriceps fat pad mass effect on the suprapatellar recess, which was associated with intermediate or fluid signal intensity of the quadriceps fat pad (chi(2) = 7.19, p = 0.0274) but with no other findings on knee MRI. Anterior knee pain at physical examination was associated with quadriceps fat pad mass effect (chi(2) = 8.76, p = 0.0031), medial collateral ligament abnormality (chi(2) = 4.83, p = 0.0031), and history of anterior knee pain (chi (2) = 22.76, p < 0.0001). CONCLUSION: Enlargement of the quadriceps fat pad on MRI has a prevalence of 12% and is significantly associated with intermediate or fluid signal intensity of the quadriceps fat pad and anterior knee pain.

Steps to take for clavicle fractures.

The bones that reach from the middle of your chest to the shoulders form the struts that make up the front of the shoulder. They can be broken when they are overstressed.

Clavicle fractures: individualizing treatment for fracture type.

Clavicle fractures are common injuries in both children and adults. In most cases, the diagnosis can be made readily from the patient's history and physical examination. X-rays are helpful to confirm the diagnosis, to assess the severity of the fracture, and to follow interval healing. Most fractures are treated nonoperatively, and surgical intervention is typically reserved for unstable distal clavicle fractures. Nonoperative options involve either a sling-and-swathe or figure-of-eight splint. Return-to-play decisions should be individualized based on the age of the patient, location and severity of the fracture, degree of clinical and radiographic healing, and the sport in which the athlete will be participating.