Models for predicting venous thromboembolism in ambulatory patients with lung cancer: A systematic review and meta-analysis.

AIMS: The incidence of venous thromboembolism (VTE) in patients with lung cancer is relatively high, and risk stratification models are vital for the targeted application of thromboprophylaxis. We aimed to review VTE risk prediction models that have been developed in patients with lung cancer and evaluated their performance. METHODS AND RESULTS: Twenty-four eligible studies involving 123,493 patients were included. The pooled incidence of VTE within 12 months was 11 % (95 % CI 8 %-14 %). With the identified four VTE risk assessment tools, meta-analyses did not show a significant discriminatory capability of stratifying VTE risk for Khorana, PROTECHT and CONKO scores. The pooled sensitivity and specificity of the Khorana score were 24 % (95 % CI 11 %-44 %) and 84 % (95 % CI 73 %-91 %) at the 3-point cut-off, and 43 % (95 % CI 35 %-52 %) and 61 % (95 % CI 52 %-69 %) at the 2-point cut-off. However, a COMPASS-CAT score of ≥ 7 points indicated a significantly high VTE risk, with a RR of 4.68 (95 % CI 1.05-20.80). CONCLUSIONS: The Khorana score lacked discriminatory capability in identifying patients with lung cancer at high VTE risk, regardless of the cut-off value. The COMPASS-CAT score had better performance, but further validation is needed. The results indicate the need for robust VTE risk assessment tools specifically designed and validated for lung cancer patients. Future research should include relevant biomarkers as important predictors and consider the combined use of risk tools. PROSPERO registration number: CRD42021245907.

Local spatial navigation or "steering" in patients with vestibular loss in a virtual reality environment.

BACKGROUND: Patients with vestibular loss have reduced wayfinding ability, but the association between vestibular loss and impaired steering spatial navigation is unclear. OBJECTIVE: To evaluate whether vestibular loss is associated with reduced steering navigation performance in a virtual reality (VR) environment containing obstacles. METHODS: 17 ambulatory adults with vestibular loss were age/sex-matched to healthy controls. Participants traversed a VR hallway with obstacles, and their navigation performance was compared using metrics such as collisions, time, total distance travelled, and speed in single and multivariate analysis. RESULTS: In univariate analysis there was no significant difference in collisions between vestibular patients and controls (1.84 vs. 2.24, p = 0.974). However, vestibular patients took more time, longer routes, and had lower speeds to complete the task (56.9 vs. 43.9 seconds, p < 0.001; 23.1 vs. 22.0 meters, p = 0.0312; 0.417 vs. 0.544 m/s, p < 0.001). These results were confirmed in multivariate analysis. CONCLUSIONS: This study found that patients with vestibular loss displayed slower gait speeds and traveled longer distances, though did not make more collisions, during a VR steering navigation task. Beyond the known influence of vestibular function on gait speed, vestibular loss may also contribute to less efficient steering navigation through an obstacle-laden environment, through neural mechanisms that remain to be elucidated.

Shoulder Injury Related to Vaccine Administration (SIRVA) Is Real: A Case Report.

This study presents a case of SIRVA-induced adhesive capsulitis and the subsequent physiotherapy intervention. It details the patient's journey using CARE guidelines. The main symptoms included persistent pain and a reduced range of motion for flexion, abduction, and internal and external rotation of the shoulder. Interventions included active and passive mobilisation via capsular stretching, and home exercise programs. At more than two years post-injury, the patient has ongoing pain, restricted shoulder movement, and disability. This highlights the importance of healthcare practitioners' knowledge of SIRVA. Vaccinating practitioners should be aware of the mechanism of injury of SIRVA for preventing such injuries. First-contact practitioners should be aware of SIRVA-induced conditions to ensure timely and correct diagnosis and management of SIRVA-induced conditions.

Statistically Optimal Cue Integration During Human Spatial Navigation.

In 2007, Cheng and colleagues published their influential review wherein they analyzed the literature on spatial cue interaction during navigation through a Bayesian lens, and concluded that models of optimal cue integration often applied in psychophysical studies could explain cue interaction during navigation. Since then, numerous empirical investigations have been conducted to assess the degree to which human navigators are optimal when integrating multiple spatial cues during a variety of navigation-related tasks. In the current review, we discuss the literature on human cue integration during navigation that has been published since Cheng et al.'s original review. Evidence from most studies demonstrate optimal navigation behavior when humans are presented with multiple spatial cues. However, applications of optimal cue integration models vary in their underlying assumptions (e.g., uninformative priors and decision rules). Furthermore, cue integration behavior depends in part on the nature of the cues being integrated and the navigational task (e.g., homing versus non-home goal localization). We discuss the implications of these models and suggest directions for future research.

Healthcare Practitioners Knowledge of Shoulder Injury Related to Vaccine Administration (SIRVA).

Background: Vaccine pharmacovigilance is at the forefront of the public eye. Shoulder Injuries Related to Vaccine Administration (SIRVA) is a poorly understood Adverse Event Following Immunisation, with iatrogenic origins. Criteria for medicolegal diagnosis of SIRVA is conflicting, current literature and educational materials are lacking, and healthcare practitioner knowledge of the condition is unknown. Methods: A cross-sectional, convenience sampled survey, utilising a validated online questionnaire assessed practitioner knowledge of SIRVA, safe injecting, and upper limb anatomy, and preferred definition for SIRVA. Results: Mean scores were moderate for safe injecting knowledge (69%), and poor for knowledge of anatomy (42%) and SIRVA (55%). Non-immunising healthcare practitioners scored significantly (p = 0.01, and < 0.05, respectively) higher than immunising practitioners for anatomy (2.213 ± 1.52 vs. 3.12 ± 1.50), and safe injecting knowledge (6.70 ± 1.34 vs. 7.14 ± 1.27). Only 52% of authorised vaccinators accurately selected a 40 × 20 mm area recommended for safe injecting. Majority (91.7%) of respondents thought nerve injuries should be included in the diagnostic criteria for SIRVA. Discussion and conclusions: Greater education and awareness of SIRVA is needed in all healthcare disciplines. Consensus regarding SIRVA definition is paramount for accurate reporting and improved future understanding of all aspects of SIRVA.

Shoulder injury related to vaccine administration (SIRVA): What do we know about its incidence and impact?

Background: Shoulder injury related to vaccine administration (SIRVA) has been recognised as the compensable term for any shoulder injury that may result from an improper vaccination technique since 2017, however, its incidence and impact remain poorly understood. Objectives: To examine knowledge of SIRVA through reported cases, determine SIRVA incidence related to COVID-19 vaccinations, and investigate recovery rates. Methods: Six pharmacovigilance agencies in the United States of America (USA), Canada, United Kingdom, European Union, Australia, and New Zealand were systematically search to identify all reported cases of SIRVA between January 2017 to July 2021. Primary outcome measures were SIRVA case reports. Secondary outcome measures included recovery status as well as vaccine received, age, and sex. SIRVA-related outcome measures were retrieved between July 18th and July 22nd 2021, with UK data received via personal correspondence. Results: Retrospective analysis yielded 505 SIRVA cases since 2017, with 330 (65%) of cases reported from January to July 2021. Sub-analysis, using COVID-19 data of 189 SIRVA cases from 891,906,986 vaccinations, estimated incidence to be 2 per 10 million. 32 cases (7%) had recovered from symptoms at the time of reporting, with 311 (62%) reported as 'not recovered', and 162 cases (32%) 'unknown'. Females represented 75% of reported cases. Conclusion: SIRVA case report numbers and incidence from COVID-19 data, compared with prior evidence, raises questions around health practitioner knowledge and reporting accuracy of SIRVA. Recovery rates are poorly understood. A global consensus definition of SIRVA and more transparent and routine reporting is required. The disproportionate representation of females is of concern with no known reasons for this disparity. Further research is needed on SIRVA knowledge in healthcare practitioners, reporting rates, incidence, management, and long-term outcomes for those impacted. Pharmacist vaccinators should be aware of their role in preventing SIRVA and be active in its detection.

Can Therapeutic Exercises Improve Proprioception in Chronic Ankle Instability? A Systematic Review and Network Meta-analysis.

OBJECTIVE: To assess exercise therapies that aim to enhance proprioception in individuals with chronic ankle instability (CAI). DATA SOURCES: Five databases (PubMed, Embase, Cochrane Library, Web of Science, and EBSCO) were searched in October 2021. STUDY SELECTION: Randomized controlled trials involving exercise therapy conducted on individuals with CAI were included. DATA EXTRACTION: Data were extracted by 2 independent reviewers using a standardized form. Methodological quality and risk of bias were assessed with the Physiotherapy Evidence Database scale. DATA SYNTHESIS: The end trial weighted mean difference and standard deviations were analyzed, and the synthetic value for the improvement in error scores of ankle joint position sense in multiple directions was evaluated. RESULTS: Eleven trials with 333 participants were eligible for inclusion in this systematic review and were included in the network meta-analysis. Foot and ankle muscle strengthening exercise showed the highest probability of being among the best treatments (surface under the cumulative ranking [SUCRA]=74.6%). The next 2 were static balance exercise only (SUCRA=67.9%) and corrective exercise (SUCRA=56.1%). The SUCRA values of proprioceptive exercise, dynamic balance exercise only, aquatic exercise, rehabilitation exercise with brace, mixed static/dynamic balance exercise, and control were at relatively low levels and scored at 49.6%, 48.8%, 47.8%, 47.7%, 44.0%, and 13.5%, respectively. CONCLUSIONS: Foot and ankle muscle strengthening exercise may have a good effect when used to improve joint position sense in individuals with CAI. The more complex balance exercise intervention becomes, the less effective the proprioceptive outcome.

Integration of visual landmark cues in spatial memory.

Over the past two decades, much research has been conducted to investigate whether humans are optimal when integrating sensory cues during spatial memory and navigational tasks. Although this work has consistently demonstrated optimal integration of visual cues (e.g., landmarks) with body-based cues (e.g., path integration) during human navigation, little work has investigated how cues of the same sensory type are integrated in spatial memory. A few recent studies have reported mixed results, with some showing very little benefit to having access to more than one landmark, and others showing that multiple landmarks can be optimally integrated in spatial memory. In the current study, we employed a combination of immersive and non-immersive virtual reality spatial memory tasks to test adult humans' ability to integrate multiple landmark cues across six experiments. Our results showed that optimal integration of multiple landmark cues depends on the difficulty of the task, and that the presence of multiple landmarks can elicit an additional latent cue when estimating locations from a ground-level perspective, but not an aerial perspective.

Much work remains to reach consensus on musculoskeletal injury risk in military service members: A systematic review with meta-analysis.

Musculoskeletal injuries are the most common reason military service members cannot perform their military duties. Not only are they costly and associated with long-term disability, often long after completion of military service, but injuries also adversely affect the military readiness of a nation. This can be seen as a threat to national security and part of the impetus behind many efforts to better understand, predict, and mitigate injury risk in the military. A systematic review of the literature published between 1995 and October 31, 2020 was conducted to identify significant risk factors of musculoskeletal injury in military populations across the world. 74 out of 170 eligible studies addressed comprehensive injuries, providing 994 unique risk factors. 46 of these studies provided data that could be included in a meta-analysis, which was possible for 15 predictor variables. Seven predictors were significant in meta-analysis: female sex(RR=1.46;95CI 1.30,1.64), high body mass index(RR=1.36;95CI 1.21,1.53), functional movement screen pain (RR=1.70;95CI 1.55,1.87) or scores ≤ 14(RR=1.42 95CI 1.29,1.56), prior injury(RR=1.54;95CI 1.32,1.80), slower running performance(RR=1.33;95CI 1.18,1.51), and poorer push-up performance(RR=1.15;95CI 1.04,1.27). Low BMI, height, weight, smoking, physical activity scores, and sit-up and jump performance were not significant risk factors in the meta-analysis. Most studies had a high risk of bias. Lack of raw data and large heterogeneity in definitions of predictors and injury outcomes limited comparison across many studies.Highlights Female sex, high body mass index, pain with functional movement screen or a score of ≤ 14, prior injury, slower running performance and poorer push-up performance were all significant predictors of musculoskeletal injury.Low body mass index, height, weight, smoking, physical activity scores, and sit-up and jump performance were not significant predictors of musculoskeletal injury.Many other predictors were present only in single studies, but large heterogeneity in definitions of both outcomes and predictors limited comparison across studies.Overall, studies assessing risk factors to predict musculoskeletal injuries in the military were at high risk for bias, especially in regards to statistical approaches.

What did the ankle say to the knee? Estimating knee dynamics during landing - A systematic review and meta-analysis.

BACKGROUND: Landing-based measures of the knee are often used to assess risk of anterior cruciate ligament (ACL) injury and inform prevention strategies. There is less understanding of the ankle's influence on knee measures during landing. OBJECTIVE: 1. Examine interactions of dynamic ankle measures alongside various subject and task characteristics on knee dynamics in vertical landing and 2. Determine whether ankle measures alone can estimate dynamic knee measures associated with ACL injury risk. DESIGN: Systematic review and meta-analysis. METHODS: Electronic databases Medline, EMBASE, CINAHL, Web of Science and Cochrane were screened for studies that included measurement of initial contact angles and internal joint moments of both the ankle and knee during landing in uninjured individuals. RESULTS: 28 studies were included for analysis. Using 1144 landing trials from 859 individuals, RRelief F algorithm ranked dynamic ankle measures more important than landing task and subject characteristics in estimating knee dynamics. An adaptive boosting model using four dynamic ankle measures accurately estimated knee extension (R2 = 0.738, RMSE = 3.65) and knee abduction (R2 = 0.999, RMSE = 0.06) at initial contact and peak knee extension moment (R2 = 0.988, RMSE = 0.13) and peak knee adduction moment (R2 = 1, RMSE = 0.00). CONCLUSIONS: Dynamic ankle measures can accurately estimate initial contact angles and peak moments of the knee in vertical landing, regardless of landing task or individual subject characteristics. This study provides a theoretical basis for the importance of the ankle in ACL injury prevention.

Musculoskeletal injuries in military personnel-Descriptive epidemiology, risk factor identification, and prevention.

OBJECTIVES: To provide an overall perspective on musculoskeletal injury (MSI) epidemiology, risk factors, and preventive strategies in military personnel. DESIGN: Narrative review. METHODS: The thematic session on MSIs in military personnel at the 5th International Congress on Soldiers' Physical Performance (ICSPP) included eight presentations on the descriptive epidemiology, risk factor identification, and prevention of MSIs in military personnel. Additional topics presented were bone anabolism, machine learning analysis, and the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on MSIs. This narrative review focuses on the thematic session topics and includes identification of gaps in existing literature, as well as areas for future study. RESULTS: MSIs cause significant morbidity among military personnel. Physical training and occupational tasks are leading causes of MSI limited duty days (LDDs) for the U.S. Army. Recent studies have shown that MSIs are associated with the use of NSAIDs. Bone MSIs are very common in training; new imaging technology such as high resolution peripheral quantitative computed tomography allows visualization of bone microarchitecture and has been used to assess new bone formation during military training. Physical activity monitoring and machine learning have important applications in monitoring and informing evidence-based solutions to prevent MSIs. CONCLUSIONS: Despite many years of research, MSIs continue to have a high incidence among military personnel. Areas for future research include quantifying exposure when determining MSI risk; understanding associations between health-related components of physical fitness and MSI occurrence; and application of innovative imaging, physical activity monitoring and data analysis techniques for MSI prevention and return to duty.

A computational cognitive model of judgments of relative direction.

In the past several decades, considerable theoretical progress has been made in understanding the role of reference frames in the encoding and retrieval of spatial information about the environment. Many of these insights have come from participants making judgments of relative direction using their memories of spatial layouts. In this task, participants are asked to imagine standing at a given location and facing a certain direction, and to point to a target location. Although this task has been widely and productively used, a computational cognitive model of judgments of relative direction has yet to be introduced. Computational modeling of judgments of relative direction is a critical next step to formulating and testing hypotheses about the cognitive processes involved in establishing and using spatial reference frames. We present an initial attempt to model judgments of relative direction and fit the model to two datasets exhibiting behavioral patterns commonly observed in the spatial memory literature. The model was able to predict many important features of these data, most notably alignment effects. We discuss directions for future modeling efforts.

A comparison of methods of assessing cue combination during navigation.

Mobile organisms make use of spatial cues to navigate effectively in the world, such as visual and self-motion cues. Over the past decade, researchers have investigated how human navigators combine spatial cues, and whether cue combination is optimal according to statistical principles, by varying the number of cues available in homing tasks. The methodological approaches employed by researchers have varied, however. One important methodological difference exists in the number of cues available to the navigator during the outbound path for single-cue trials. In some studies, navigators have access to all spatial cues on the outbound path and all but one cue is eliminated prior to execution of the return path in the single-cue conditions; in other studies, navigators only have access to one spatial cue on the outbound and return paths in the single-cue conditions. If navigators can integrate cues along the outbound path, single-cue estimates may be contaminated by the undesired cue, which will in turn affect the predictions of models of optimal cue integration. In the current experiment, we manipulated the number of cues available during the outbound path for single-cue trials, while keeping dual-cue trials constant. This variable did not affect performance in the homing task; in particular, homing performance was better in dual-cue conditions than in single-cue conditions and was statistically optimal. Both methodological approaches to measuring spatial cue integration during navigation are appropriate.

Does ankle tape improve proprioception acuity immediately after application and following a netball session? A randomised controlled trial.

OBJECTIVES: To assess whether ankle tape applied by a Sport and Exercise Physiotherapist (SEP) or self-applied by the athlete results in a change in proprioception and whether it is maintained during a netball session. DESIGN: Randomised controlled trial. SETTING: Australian Institute of Sport. PARTICIPANTS: 53 pre-elite netball athletes. MAIN OUTCOME MEASURES: Athlete proprioception was assessed using the Active Movement Extent Discrimination Apparatus (AMEDA) on four occasions for each taping condition: 1) pre-tape, 2) post-tape, 3) post-netball & 4) post-netball no-tape. RESULTS: Mixed effect linear models were used for analysis. A significant increase in proprioception was observed when self-tape: 0.022 (95% CI: [-0.000 - 0.044], p = 0.05), and SEP tape: 0.034 (95% CI: [0.012-0.055], p < 0.01), were initially applied. These improvements were maintained during a netball session for both, self-taping: 0.01 (95% CI: [-0.01 - 0.02], p = 0.45) and SEP-taping: <0.01 (95% CI: [-0.02 - 0.01], p = 0.56). Results also indicate there was no significant difference between taping conditions (ß = -0.001, 95% CI: [-0.02 - 0.02], p = 0.90). CONCLUSIONS: Proprioception improves and is maintained during a netball session with either SEP or self-applied taping.

A prospective study of health problems at the 2018 17/U and 19/U Australian National Netball Championships with comparison of surveillance methodology.

OBJECTIVE: To investigate the incidence, site, nature and cause of injuries sustained during and four weeks following the 2018 Australian National Netball Championships (ANNC's) using medical attention and self-report surveillance tools. DESIGN: Prospective cohort study. METHOD: Injuries were recorded prospectively using medical attention and self-report data collection methods. One hundred and ninety-two athletes competed at the 2018 ANNC's with 96 athletes in each age group (17/U & 19/U). RESULTS: There were 103 medical attention injuries sustained by 80 athletes resulting in an incidence rate of 89.4 per 1000 player hours. The most frequently recorded medical attention injury diagnoses across both age groups were lateral ankle ligament sprain (n=14, 13.6%), foot blisters (n=11, 10.7%), and lumbar pain (n=10, 9.7%). Ankle sprains (n=4), anterior cruciate ligament (ACL) ruptures (n=3) and concussion (n=3) recorded as the highest sports incapacity injuries. The self-report data collection revealed that 46 (27.2%) athletes arrived at the tournament with an existing self-reported injury/illness and 57 (39.3%) athletes had a self-reported injury/illness at the conclusion of the ANNC (RR 1.44 95%CI 1.05-1.99, p=0.030). CONCLUSION: There are no recent studies reporting injury rates specifically in pre-elite netball players. This study found an incidence rate of 89.4 per 1000 player hours. Ankle sprains are the highest medical attention and sports-incapacity injury in pre-elite netball athletes. Foot blisters and low back pain also feature in the highest medical attention injuries and ACL rupture and concussion were high sports incapacity injuries at the ANNC's. Finally, combining both the medical attention and self-report injury/illness data collection methods identified more injuries/illnesses than the use of one method alone.

Age has a minimal effect on knee kinematics: A cross-sectional 3D/2D image-registration study of kneeling.

INTRODUCTION: Kneeling is an activity of daily living which becomes difficult with knee pathology and increasing age. This study aimed to capture kneeling kinematics in six-degrees-of-freedom in healthy adults as a function of age. METHODS: 67 healthy knee participants aged from 20 to 90 years were categorised into four 20-year age-groups. 3D knee kinematics were captured using 3D/2D image-registration of CT scan and fluoroscopy during kneeling. Kinematic variables of position, displacement and rate-of-change in six-degrees-of-freedom were compared between age-groups while controlling for University of California Los Angeles activity scale and the Assessment of Quality of Life physical score. RESULTS: Over the entire kneeling cycle there were few differences between the age-groups. Results are reported as pairwise contrasts. At 110° flexion, 80+ knees were more varus than 20-39 and 40-69 (4.9° (95%CI: 0.6°, 9.1°) and 6.4° (2.1°, 10.7°), respectively). At 120° flexion, the 80+ age-group femur was 5.5 (0.0, 11.0) mm more anterior than 20-39. Between 120° to maximum flexion, 80+ knees rotated into valgus more than 20-39, 40-59 and 60-79 (5.5° (1.2°, 9.8°); 5.5° (1.1°, 9.8°); and 4.5° (0.9°, 7.5°), respectively). CONCLUSION: This is the first study to report kneeling knee kinematics of ageing using 3D/2D image registration. We found that ageing does not change knee kinematics under 80 years, and there are minimal changes between 120° and maximum flexion between the younger and 80+ age-groups. Thus, difficulty kneeling should not be considered to be an inevitable consequence of ageing.

Injury prevention strategies specific to pre-elite athletes competing in Olympic and professional sports - A systematic review.

OBJECTIVES: To describe and evaluate injury prevention interventions for pre-elite athletes who compete in an Olympic or professional sport. DESIGN: Systematic review. METHODS: This review was prospectively registered (PROSPERO CRD42017065083) and a systematic electronic search was conducted in May 2017. The following inclusion criteria were applied: (1) studies including and analysing data specific to pre-elite athletes (determined by the T3/T4 levels of the FTEM model); (2) featured injury prevention interventions; (3) provided sufficient data related to injury such that the effect can be analysed e.g. injury rates, incidence, prevalence, injury rate ratios; (4) featured randomised and non-randomised controlled trials or prospective cohorts. RESULTS: A total of 13,480 articles were retrieved with 121 titles identified and 11 studies satisfying the inclusion criteria. No studies demonstrated a low risk of bias. Four different interventions were identified: exercise (n=7, 64%), psychological (n=2, 18%), equipment (n=1, 9%), nutrition (n=1, 9%). Of the seven exercise interventions, four showed a protective effect and three found no significant effect, providing conflicting evidence. Caution is advised due to high risk of bias, low intervention reporting and minimal evidence for implementation planning in all seven studies. CONCLUSIONS: There is limited evidence from level 2 and 3 studies suggesting exercise and psychology interventions may prevent injury in pre-elite athletes. There is an absence of evidence to support the use of equipment and nutrition interventions in pre-elite athletes. There is a need for quality research designs confirming the clinical impact of existing injury prevention interventions for pre-elite athletes.

Squatting, lunging and kneeling provided similar kinematic profiles in healthy knees-A systematic review and meta-analysis of the literature on deep knee flexion kinematics.

BACKGROUND: Understanding healthy deep flexion kinematics will inform the design of conservative clinical rehabilitation strategies for knee osteoarthritis and contribute to improved knee prosthesis design. This study is a systematic review and meta-analysis of the kinematic outcomes measured at the healthy tibiofemoral joint during loaded deep knee flexion. METHODS: A computerised literature search and bibliography review without date restriction identified twelve studies with 164 participants aged 25-61 years in-vivo, and 69-93 years in-vitro. Flexion higher than 120° was achieved by squatting, lunging or kneeling. Measurement technologies in-vivo included radiographs, open MRI and 2D-3D MRI or CT image registration on fluoroscopy. Microscribe was used in-vitro. RESULTS: Outcomes were either six degrees-of-freedom based on femur movement or contact patterns on the tibial plateau. The meta-analysis demonstrated that in-vivo, between 120° and 135° of flexion, the tibia internally rotated (mean difference (MD) = 4.6°, 95% CI 3.55° to 5.64°). Both the medial-femoral-condyle and lateral-femoral-condyle translated posteriorly, (MD = 10.4 mm, 95% CI 6.9 to 13.9 mm) and (MD = 5.55 mm, 95% CI 4.64 to 6.46 mm) respectively. There was some evidence of femoral medial translation (3.8 mm) and adduction (1.9° to 3.3°), together with medial compression (1.7 mm) and lateral distraction (1.9) mm. CONCLUSIONS: Across the in-vivo studies, consistent kinematic patterns emerged; despite the various measurement technologies and reference methods. In contrast, in-vivo and in-vitro results were contradictory. TRIAL REGISTRATION: This systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 25 February 2017 (registration number: 42017057614).

Medial and lateral hamstrings and quadriceps co-activation affects knee joint kinematics and ACL elongation: a pilot study.

BACKGROUND: Many injury prevention and rehabilitation programs aim to train hamstring and quadriceps co-activation to constrain excessive anterior tibial translation and protect the anterior cruciate ligament (ACL) from injury. However, despite strong clinical belief in its efficacy, primary evidence supporting training co-activation of the hamstrings and quadriceps muscles for ACL injury prevention and rehabilitation is quite limited. Therefore, the purpose of the study presented in this paper was to determine if hamstring-quadriceps co-activation alters knee joint kinematics, and also establish if it affects ACL elongation. METHODS: A computed tomography (CT) scan from each participant's dominant leg was acquired prior to performing two step-ups under fluoroscopy: one with 'natural' hamstring-quadriceps co-activation, one with deliberate co-activation. Electromyography was used to confirm increased motor unit recruitment. The CT scan was registered to fluoroscopy for 4-D modeling, and knee joint kinematics subsequently measured. Anterior cruciate ligament attachments were mapped to the 4-D models and its length was assumed from the distance between attachments. Anterior cruciate ligament elongation was derived from the change in distance between those points as they moved relative to each other. RESULTS: Reduced ACL elongation as well as knee joint rotation, abduction, translation, and distraction was observed for the step up with increased co-activation. A relationship was shown to exist for change in ACL length with knee abduction (r = 0.91; p ≤ 0.001), with distraction (r = -0.70; p = 0.02 for relationship with compression), and with anterior tibial translation (r = 0.52; p = 0.01). However, ACL elongation was not associated with internal rotation or medial translation. Medial hamstring-quadriceps co-activation was associated with a shorter ACL (r = -0.71; p = 0.01), and lateral hamstring-quadriceps co-activation was related to ACL elongation (r = 0.46; p = 0.05). CONCLUSION: Net co-activation of the hamstrings and quadriceps muscles will likely reduce ACL elongation provided that the proportion of medial hamstring-quadriceps co-activation exceeds lateral.

Functional performance deficits associated with ligamentous instability at the ankle.

OBJECTIVES: To examine whether ankle anterior drawer ligament laxity is associated with deficits in performance testing among otherwise healthy sportspeople. DESIGN: Cross-sectional cohort study. METHODS: Eighty-six volunteers from among sports participants at a military academy consented to the use of their pre-participation musculoskeletal screening information for the lower limb, and to an additional test of ankle proprioception. The lower limb screening included tests of ankle ligament laxity, dorsiflexion range of movement, single leg hop-for-distance, hexagon agility hopping test, and hop-and-hold landing stability test. RESULTS: There was a significant difference between lax and stable ankles on the 4 screening tests when they were examined together with MANOVA (F=3.52, df=4, 167, p=0.009, Wilks' Lambda=0.92). Independent t-tests showed worse performance on the hop-for-distance (p=0.001), hexagon hop (p=0.039) and the proprioception tests (p=0.033) associated with laxity. Comparing stable and unstable ankles in the same individual, paired t-tests showed significantly lower hop counts for lax ankles on the hexagon hop test (p=<0.001). CONCLUSIONS: Ankle ligament laxity is associated with persisting deficits in explosive power, agility and proprioception, as demonstrated by less hopping distance, fewer hops in hexagon hop testing, and reduced proprioceptive acuity, despite ongoing participation in sport. Attention to maximising sport-related performance in the late stages of rehabilitation is suggested as an essential addition to clinical management of these injuries.