Are two-dimensional measured frontal plane angles related to three-dimensional measured kinematic profiles during running?

OBJECTIVES: To investigate the temporal relationship between two-dimensional measured frontal plane joint angles and three-dimensional measured kinematic profiles during the stance phase of running, and to assess the intra- and intertester reliability of the two-dimensional angles. DESIGN: Observational study. SETTING: Research laboratory. PARTICIPANTS: Fifteen injury-free elite athletes. MAIN OUTCOME MEASURES: Contralateral pelvic drop (CPD), femoral adduction (FA), hip adduction (HA) and knee valgus (KV) were measured at the deepest landing position during midstance with two-dimensional video analysis during running. CPD, HA and knee abduction were measured continuously during the entire stance phase through three-dimensional motion analysis. One-dimensional statistical parametric mapping was used to examine the temporal relationships between the two-dimensional angles and three-dimensional kinematic profiles. In addition, intra-class correlation coefficients (ICC) were calculated to assess the intra- and intertester reliability of the two-dimensional angles. RESULTS: Two-dimensional CPD, FA and HA were significantly related to the three-dimensional HA kinematic profile. Two-dimensional CPD was significantly related to the three-dimensional CPD kinematic profile. No significant relationship was found between two-dimensional KV and three-dimensional knee abduction. Excellent intra- and intertester reliability was found for the two-dimensional angles (ICC 0.90-0.99). CONCLUSIONS: These findings support implementing two-dimensional video analysis to evaluate CPD and HA during running.

Postural Stability During Single-Leg Stance: A Preliminary Evaluation of Noncontact Lower Extremity Injury Risk.

Study Design Controlled laboratory study with a prospective cohort design. Background Postural stability deficits during single-leg stance have been reported in persons with anterior cruciate ligament (ACL) injury, ACL reconstruction, and chronic ankle instability. It remains unclear whether impaired postural stability is a consequence or cause of these injuries. Objectives To prospectively investigate whether postural stability deficits during single-leg stance predict noncontact lower extremity injuries. Methods Fifty injury-free female athletes performed a transition task from double-leg stance to single-leg stance with eyes closed. Center-of-pressure displacement, the main outcome variable, was measured during the first 3 seconds after the time to a new stability point was reached during single-leg stance. Noncontact lower extremity injuries were recorded at a 1-year follow-up. Results Six participants sustained a noncontact ACL injury or ankle sprain. Center-of-pressure displacement during the first 3 seconds after the time to a new stability point was significantly increased in the injured (P = .030) and noninjured legs (P = .009) of the injured group compared to the respective matched legs of the noninjured group. The area under the receiver operating characteristic curve (AUC) analysis revealed significant discriminative accuracy between groups for the center-of-pressure displacement during the first 3 seconds after the time to a new stability point of the injured (AUC = 0.814, P = .015) and noninjured legs (AUC = 0.897, P = .004) of the injured group compared to the matched legs of the noninjured group. Conclusion This preliminary study suggests that postural stability measurements during the single-leg stance phase of the double- to single-leg stance transition task may be a useful predictor of increased risk of noncontact lower extremity injury. Further research is indicated. Level of Evidence Prognosis, level 4. J Orthop Sports PhysTher 2016;46(8):650-657. Epub 3 Jul 2016. doi:10.2519/jospt.2016.6278.

Can two-dimensional video analysis during single-leg drop vertical jumps help identify non-contact knee injury risk? A one-year prospective study.

BACKGROUND: Previous studies showed that the amount of hip flexion and the combination of knee valgus and lateral trunk motion, measured with two-dimensional video analysis, were related to three-dimensional measured knee joint moments during single-leg drop vertical jumps, but it remains unclear whether these measurements can be used to identify non-contact knee injury risk. METHODS: Fifty injury-free female athletes participated in the study. Two-dimensional video analysis was used to measure hip flexion, knee valgus and lateral trunk motion angles during single-leg drop vertical jumps. Time loss non-contact knee injuries were registered during a one-year follow-up. Independent t-tests and receiver operating characteristic analysis were used to analyze the predictive ability of the two-dimensional angles. FINDINGS: Seven participants sustained a time loss non-contact knee injury. Hip flexion was not significantly different between groups (P>.05). The combination of knee valgus and lateral trunk motion was significantly smaller in the injured (P=.036) and non-injured legs (P=.009) of the future injured group compared with the respective matched leg of the non-injured group. The receiver operating characteristic analysis showed a significant discriminative accuracy between groups for the combination of knee valgus and lateral trunk motion of the uninjured leg of the future injured group with the matched leg of the non-injured group (area under curve=0.803; P=.012). INTERPRETATION: The measurement of a combination of increased knee valgus and ipsilateral trunk motion during the single-leg drop vertical jump with two-dimensional video analysis can be used to help identify female athletes with increased non-contact knee injury risk.

Patellar tendinopathy in athletes: current diagnostic and therapeutic recommendations.

Formerly known as 'jumper's knee', patellar tendinopathy gives rise to considerable functional deficit and disability in recreational as well as professional athletes. It can interfere with their performance, often perseveres throughout the sporting career and may be the primary cause to end it. The diagnosis of patellar tendinopathy is primarily a clinical one but new imaging techniques, such as Doppler ultrasonography, may provide additional diagnostic value. Current therapeutic protocols are characterised by wide variability ensuing from anecdotal experience rather than evidence. Moreover, numerous reports in recent years have shattered previous doctrines and dogmatic belief on tendon overuse. Histopathological and biochemical evidence has indicated that the underlying pathology of tendinopathy is not an inflammatory tendinitis but a degenerative tendinosis. Consequently, pain in chronic patellar tendinopathy is not inflammatory in nature, but its exact origin remains unexplained. In pursuit of pathology- and evidence-based management, conservative therapy should be shifted from anti-inflammatory strategies towards a complete rehabilitation with eccentric tendon strengthening as a key element. If conservative management fails, surgery is opted for. However, considering the heterogeneity of surgical procedures and the absence of randomised studies, no conclusive evidence can be drawn from the literature regarding the effectiveness of surgical treatment for patellar tendinopathy. Parallel with the improved knowledge on the pathophysiology and pain mechanisms in patellar tendinopathy, new treatment strategies are expected to emerge in the near future.

Correlation between power Doppler ultrasonography and clinical severity in Achilles tendinopathy.

Twenty-five patients with chronic Achilles tendinopathy were clinically and ultrasonographically evaluated. A positive correlation existed between power Doppler ultrasonography (PDU) and tendon thickness (r=0.63, p<0.001) and patient's age (r=0.40, p<0.05). A negative correlation existed between PDU and a functional test (number of toe raises to pain) (r=-0.57, p<0.005) and one recorded item of the Victorian Institute of Sport Assessment Achilles score (VISA-A questionnaire, item 6: jumping capability) (r=-0.46, p<0.05). Three patients had no detectable blood flow on PDU. PDU of Achilles tendons does not seem to be strictly related to symptoms but rather to functionality and chronicity of tendinopathy as indicated by toe-raises testing, jumping capability, patient age and tendon thickening.

Cross-sectional outcome analysis of athletes with chronic patellar tendinopathy treated surgically and by extracorporeal shock wave therapy.

OBJECTIVE: To compare the outcome of chronic patellar tendinopathy treated surgically and by extracorporeal shock wave therapy. DESIGN: Cross-sectional outcome analysis. SETTING: University Hospital Pellenberg, Leuven, Belgium. PATIENTS AND INTERVENTIONS: Of a total of 27 patients (28 knees) with chronic patellar tendinopathy, 13 were treated surgically, and 14 (15 knees) received extracorporeal shock wave therapy. MAIN OUTCOME MEASUREMENTS: Functional outcome questionnaire: Victorian Institute of Sport Assessment score, Visual Analog Scale, and Roles and Maudsley classification. RESULTS: At an average of 6 months of follow-up, the mean Victorian Institute of Sport Assessment and Visual Analog Scale scores for the extracorporeal shock wave therapy group were 78.8 +/- 28.7 and 9 +/- 2, respectively, which improved to 83.9 +/- 28.6 and 9 +/- 2, respectively, at 22.1 months. The surgery group scored 70.7 +/- 22.2 points on the Victorian Institute of Sport Assessment at an average of 26.3 months of follow-up (p = 0.41 and p = 0.18) and 8 +/- 3 on the Visual Analog Scale (p = 0.14). In the extracorporeal shock wave therapy group, 5 (33%) patients rated their pain status at 22.1 months as excellent, 5 (33%) as good, 2 (13%) as fair, and 2 (13%) as poor. In the surgery group, 4 (33%) evaluated the result as excellent, 3 (25%) as good, 3 (25%) as fair, and 2 as poor (17%). CONCLUSIONS: Extracorporeal shock wave therapy shows a comparable functional outcome to surgery in a cross-sectional analysis of patients with chronic proximal patellar tendinopathy resistant to conservative treatment.