Accuracy and Reliability of Examiners’ Observations of Pre-Practice Warm-Up and FIFA 11+ Injury Prevention Program Exercises

Background: The Fédération Internationale de Football Association (FIFA) 11+ is an injury prevention program that decreases the incidence of lower extremity injuries. The purpose of the current study was to understand what specific exercises prevented injury from occurring. We thus developed and tested a form to identify these exercises. We hypothesize that trained examiners could accurately and reliably use this form to identify and record individual exercises performed during preparticipation warm-up. Methods: A repeated-measures study design was used in this investigation. After observing five prepractice warm-up videos obtained from multiple high schools, 11 examiners observed and recorded performed exercises at two different times. The videos included four soccer teams and one American football team. Accuracy, interexaminer reliability, and intraexaminer reliability were assessed. Sensitivity, specificity, accuracy, and percent agreement with a FIFA 11+ expert were measured for each exercise component. Results: The intraclass correlation coefficients between examiners and individually ranged from 0.22 to 1.00 and 0.58 to 1.00, respectively. Reliability was lowest for exercises with similar movements. The percent agreement across all examiners for individual exercises ranged from 20% to 100%. Additionally, the percent agreement between each examiner and the “gold standard” examiner was high (range, 69.6% to 90.4%). For exercises with similar movements, accuracy and reliability were considerably improved (97%) when combined into one category. Conclusion: We determined that trained examiners with different backgrounds and experience can make accurate and reliable observations of most exercises observed in warm-up programs. Using the proposed form, researchers can accurately record exercises and perform quality and fidelity assessments of warm-up exercise routines

Variations in Varus/Valgus and Internal/External Rotational Knee Laxity and Stiffness Across the Menstrual Cycle

Abstract: Cyclic variations in genu recurvatum (GR), general joint laxity (GJL), varus-valgus (VV), and internal-external (IER) rotational laxities and stiffnesses were examined in 64 females and 43 males at two time points during the females' menstrual cycle [days of minimum (T1) and maximum (T2) anterior knee laxity (AKL)]. Cyclic increases in AKL (9.5%), GR (37.5%), and GJL (13.6%) were observed in females but not males from T1 to T2 (p < 0.001). Cyclic increases in VV and IER laxity were negligible (1.5-3.2%, p > 0.320). Females compared to males had lower overall VV stiffness at T2 (F 37% <M) vs. T1 (F 26.9% <M; p = 0.011), but no difference across time points for IER stiffness (p = 0.452). Across both time points, females had consistently greater VV (30.2%) and IER (20%) laxity and less VV (32.5%) and IER (24.3%) incremental stiffness (p < 0.001). Low-to-moderate associations were observed between AKL, GR, and GJL with VV and IER laxities and stiffnesses in females as measured at T1 and the change in values from T1 to T2. Whether these findings reflect ligament-specific responses to hormone changes, or implicate changes in injury risk potential across the menstrual cycle requires further study. Article: The potential consequences of varus-valgus (VV) and internal-external (IER) rotational laxity and stiffness of the tibiofemoral joint on knee joint biomechanics have recently been examined. Where rotational laxity is a measure of the rotation of the tibia relative to the femur between fixed torque magnitudes, torsional stiffness represents the torque-rotation response of the joint across a range of applied torques, which may be useful in determining where in the range the knee joint is more or less resistive to the applied torques

Inter- and intra-rater reliabilities of the Beighton Score compared to the Contompasis Score to assess Generalised Joint Hypermobility

Objectives: Generalized Joint Hypermobility [GJH] is a common connective tissue disorder associated with a range of musculoskeletal complaints. An effective screening tool to assess GJH may influence our understanding and choice of management. Diagnosis is clinical, using tools such as the Beighton Hypermobility Score and the Contompasis Scoring System. The comparable reliability of these tools has not been previously reported. The aim of the present study was to compare the intra- and the inter-rater reliability of the Beighton Score to the Contompasis Score to assess GJH. Methods: This was an observational study assessing 36 pain-free participants; 27 females and nine males; aged 18–32 years. Participants were assessed in random order, by two researchers over two sessions to determine intra- and inter-rater analyses. Intraclass Correlation Coefficient [ICC] and weighted Kappa statistics were used to calculate the level of agreement. Results: The intra- [ICC: 0.71–0.82] and the inter- [ICC: 0.72–0.80] rater reliability of the Beighton Score was substantial to almost perfect. The Contompasis Score displayed substantial to almost perfect intra-rater [ICC: 0.73–0.82] reliability and moderate to substantial inter-rater [ICC: 0.58–0.62] reliability. Conclusions: The present study provides an indication of the measurement capabilities of the Beighton and Contompasis Scores. The Beighton score appears to be superior compared with the Contompasis score particularly based on inter-rater reliability

Effects of acute fatigue on the volitional and magnetically-evoked electromechanical delay of the knee flexors in males and females

Neuromuscular performance capabilities, including those measured by evoked responses, may be adversely affected by fatigue; however, the capability of the neuromuscular system to initiate muscle force rapidly under these circumstances is yet to be established. Sex-differences in the acute responses of neuromuscular performance to exercise stress may be linked to evidence that females are much more vulnerable to ACL injury than males. Optimal functioning of the knee flexors is paramount to the dynamic stabilisation of the knee joint, therefore the aim of this investigation was to examine the effects of acute maximal intensity fatiguing exercise on the voluntary and magnetically-evoked electromechanical delay in the knee flexors of males and females. Knee flexor volitional and magnetically-evoked neuromuscular performance was assessed in seven male and nine females prior to and immediately after: (i) an intervention condition comprising a fatigue trial of 30-seconds maximal static exercise of the knee flexors, (ii) a control condition consisting of no exercise. The results showed that the fatigue intervention was associated with a substantive reduction in volitional peak force (PFV) that was greater in males compared to females (15.0%, 10.2%, respectively, p < 0.01) and impairment to volitional electromechanical delay (EMDV) in females exclusively (19.3%, p < 0.05). Similar improvements in magnetically-evoked electromechanical delay in males and females following fatigue (21%, p < 0.001), however, may suggest a vital facilitatory mechanism to overcome the effects of impaired voluntary capabilities, and a faster neuromuscular response that can be deployed during critical times to protect the joint system

The effects of stochastic resonance electrical stimulation and neoprene sleeve on knee proprioception

<p>Abstract</p> <p>Background</p> <p>A variety of knee injuries and pathologies may cause a deficit in knee proprioception which may increase the risk of reinjury or the progression of disease. Stochastic resonance stimulation is a new therapy which has potential benefits for improving proprioceptive function. The objective of this study was to determine if stochastic resonance (SR) stimulation applied with a neoprene sleeve could improve knee proprioception relative to a no-stimulation/no-sleeve condition (control) or a sleeve alone condition in the normal, healthy knee. We hypothesized that SR stimulation when applied with a sleeve would enhance proprioception relative to the control and sleeve alone conditions.</p> <p>Methods</p> <p>Using a cross-over within subject design, twenty-four healthy subjects were tested under four combinations of conditions: electrical stimulation/sleeve, no stimulation/sleeve, no stimulation/no sleeve, and stimulation/no sleeve. Joint position sense (proprioception) was measured as the absolute mean difference between a target knee joint angle and the knee angle reproduced by the subject. Testing was conducted during both partial-weight bearing (PWB) and non-weight bearing (NWB) tasks. Differences in joint position sense between the conditions were evaluated by repeated-measures analysis of variance testing.</p> <p>Results</p> <p>Joint position sense error during the stimulation/sleeve condition (2.48° ± 1.32°) was found to be more accurate (P < 0.05) relative to the control condition (3.35° ± 1.63°) in the PWB task. No difference in joint position sense error was found between stimulation/sleeve and sleeve alone conditions for the PWB task. Joint position sense error was not found to differ between any of the conditions for the NWB task.</p> <p>Conclusion</p> <p>These results suggest that SR electrical stimulation when combined with a neoprene sleeve is an effective modality for enhancement of joint proprioception in the PWB knee. We believe these results suggest the need for further study of the potential of SR stimulation to correct proprioceptive deficits in a clinical population with knee injury/pathology or in subjects at risk of injury because of a proprioceptive deficit.</p

Anterior Cruciate Ligament Reconstruction in Patients with Generalized Joint Laxity

Generalized joint laxity is a genetically determined component of overall joint flexibility. The incidence of joint laxity in the overall population is approximately 5% to 20%, and its prevalence is higher in females. Recently it was noticed that individuals with generalized joint laxity are not only prone to anterior cruciate ligament injuries but also have inferior results after a reconstruction. Therefore, an anterior cruciate ligament reconstruction in patients with generalized laxity should be undertaken with caution due to the higher expected failure rate from the complexity of problems associated with this condition. It is also necessary to identify the risk factors for the injury as well as for the post operative outcome in this population. A criterion that includes all the associated components is necessary for the proper screening of individuals for generalized joint laxity. Graft selection for an anterior cruciate reconstruction in patients with ligament laxity is a challenge. According to the senior author, a hamstring autograft is an inferior choice and a double bundle reconstruction with a quadriceps tendon-bone autograft yields better results than a single bundle bone-patella tendon-bone autograft. Future studies comparing the different grafts available might be needed to determine the preferred graft for this subset of patients. Improved results after an anterior cruciate ligament reconstruction can be achieved by proper planning and careful attention to each step beginning from the clinical examination to the postoperative rehabilitation