An investigation of motor learning during side-step cutting, design of a randomised controlled trial

BACKGROUND: Of all athletic knee injuries an anterior cruciate ligament (ACL) rupture results in the longest time loss from sport. Regardless of the therapy chosen, conservative or reconstructive, athletes are often forced to reduce their level of physical activity and their involvement in sport. Moreover, a recent review reported prevalences of osteoarthritis ranging from 0% to 13% for patients with isolated ACL-deficient (ACL-D) knees and respectively 21% to 48% in patients with combined injuries. The need for ACL injury prevention is clear. The identification of risk factors and the development of prevention strategies may therefore have widespread health and economic implications. The focus of this investigation is to assess the role of implicit and explicit motor learning in optimising the performance of a side-step-cutting task. METHODS/DESIGN: A randomized controlled laboratory study will be conducted. Healthy basketball players, females and males, 18 years and older, with no previous lower extremity injuries, playing at the highest recreational level will be included. Subjects will receive a dynamic feedback intervention. Kinematic and kinetic data of the hip, knee and ankle and EMG activity of the quadriceps, hamstrings and gastrocnemius will be recorded. DISCUSSION: Female athletes have a significantly higher risk of sustaining an ACL injury than male athletes. Poor biomechanical and neuromuscular control of the lower limb is suggested to be a primary risk factor of an ACL injury mechanism in females. This randomized controlled trial has been designed to investigate whether individual feedback on task performance appears to be an effective intervention method. Results and principles found in this study will be applied to future ACL injury prevention programs, which should maybe more focus on individual injury predisposition. TRIAL REGISTRATION: Trial registration number NTR2250

The Achilles tendon Total Rupture Score is a responsive primary outcome measure:an evaluation of the Dutch version including minimally important change

PURPOSE: Aim of this study was to evaluate the responsiveness of the Dutch version of the Achilles tendon Total Rupture Score (ATRS-NL). METHODS: Patients (N = 47) completed the ATRS-NL at 3 and 6 months after Achilles tendon rupture (ATR). Additionally, they filled out the Euroqol-5D-5L (EQ-5D-5L) and Global Rating of Change Score (GRoC). Effect sizes (ES) and standardized response means (SRM) were calculated. The anchor-based method for determining the minimally important change (MIC) was used. GRoC and improvement on the items mobility and usual activities on the EQ-5D-5L served as external criteria. The scores on these anchors were used to categorize patients' physical functioning as improved or unchanged between 3 and 6 months after ATR. Receiver operating curve (ROC) analysis was performed, with the calculation of the area under the ROC curve (AUC) and the estimation of MIC values using the optimal cut-off points. RESULTS: There was a large change (ES: 1.58) and good responsiveness (SRM: 1.19) of the ATRS-NL between 3 and 6 months after ATR. Using ROC analysis, the MIC values ranged from 13.5 to 28.5 for reporting improvement on EQ-5D-5L mobility and GRoC, respectively. The AUC of improvement on mobility and improvement on GRoC were > 0.70. CONCLUSION: The ATRS-NL showed good responsiveness in ATR patients between 3 and 6 months after injury. Use of this questionnaire is recommended in clinical follow-up and longitudinal research of ATR patients. MIC values of 13.5 and 28.5 are recommended to consider ATR patients as improved and greatly improved between 3 and 6 months after ATR. LEVEL OF EVIDENCE: II

No effect of a graded training program on the number of running-related injuries in novice runners

Background: Although running has positive effects on health and fitness, the incidence of a running-related injury (RRI) is high. Research on prevention of RRI is scarce; to date, no studies have involved novice runners. Hypothesis: A graded training program for novice runners will lead to a decrease in the absolute number of RRIs compared with a standard training program. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: GRONORUN (Groningen Novice Running) is a 2-armed randomized controlled trial comparing a standard 8-week training program (control group) and an adapted, graded, 13-week training program (intervention group), on the risk of sustaining an RRI. Participants were novice runners (N = 532) preparing for a recreational 4-mile (6.7-km) running event. The graded 13-week training program was based on the 10% training rule. Both groups registered information on running characteristics and RRI using an Internet-based running log. The primary outcome measure was RRIs per 100 participants. An RRI was defined as any musculoskeletal complaint of the lower extremity or back causing a restriction of running for at least 1 week. Results: The graded training program was not preventive for sustaining an RRI (χ2 = 0.016, df = 1, P = .90). The incidence of RRI was 20.8% in the graded training program group and 20.3% in the standard training program group. Conclusions: This randomized controlled trial showed no effect of a graded training program (13 weeks) in novice runners, applying the 10% rule, on the incidence of RRI compared with a standard 8-week training program

Running a Marathon-Its Influence on Achilles Tendon Structure

Context: Several studies have been conducted to better understand the effect of load on the Achilles tendon structure. However, the effect of a high cumulative load consisting of repetitive cyclic movements, such as those that occur during the running of a marathon, on Achilles tendon structure is not yet clear. Clinicians, coaches, and athletes will benefit from knowledge about the effects of a marathon on the structure of the Achilles tendon. Objective: To investigate the short-term response of the Achilles tendon structure to running a marathon. Design: Case series (prospective). Setting: Sports medicine centers. Patients or Other Participants: Ten male nonelite runners who ran in a marathon. Main Outcomes Measure(s): Tendon structure was assessed before and 2 and 7 days after a marathon using ultrasound tissue characterization (UTC), an imaging tool that quantifies tendon organization in 4 echo types (I–IV). Echo type I represents the most stable echo pattern, and echo type IV, the least stable. Results: At 7 days postmarathon, both the insertional and midportion structure changed significantly. At both sites, the percentage of echo type II increased (insertion P, .01; midportion P ¼ .02) and the percentages of echo types III and IV decreased (type III: insertion P ¼ .01; midportion P ¼ .02; type IV: insertion P ¼ .01; midportion P, .01). Additionally, at the insertion, the percentage of echo type I decreased (P, .01). Conclusions: We observed the effects of running a marathon on the Achilles tendon structure 7 days after the event. Running the marathon combined with the activity performed shortly thereafter might have caused the changes in tendon structure. This result emphasizes the importance of sufficient recovery time after running a marathon to prevent overuse injuries

Barriers and facilitators perceived by healthcare professionals for implementing lifestyle interventions in patients with osteoarthritis:a scoping review

OBJECTIVE: To provide an overview of barriers and facilitators that healthcare professionals (HCPs) perceive regarding the implementation of lifestyle interventions (LIs) in patients with hip and/or knee osteoarthritis (OA). DESIGN: Scoping review. DATA SOURCES: The databases PubMed, Embase, CINAHL, PsycINFO and the Cochrane Library were searched from inception up to January 2021. ELIGIBILITY CRITERIA: Primary research articles with a quantitative, qualitative or mixed-methods design were eligible for inclusion if they reported: (1) perceptions of primary and/or secondary HCPs (population); (2) on implementing LIs with physical activity and/or weight management as key components (concept) and (3) on conservative management of hip and/or knee OA (context). Articles not published in English, German or Dutch were excluded. DATA EXTRACTION AND SYNTHESIS: Barriers and facilitators were extracted by two researchers independently. Subsequently, the extracted factors were linked to a framework based on the Tailored Implementation for Chronic Diseases checklist. RESULTS: Thirty-six articles were included. In total, 809 factors were extracted and subdivided into nine domains. The extracted barriers were mostly related to non-optimal interdisciplinary collaboration, patients’ negative attitude towards LIs, patients’ low health literacy and HCPs’ lack of knowledge and skills around LIs or promoting behavioural change. The extracted facilitators were mostly related to good interdisciplinary collaboration, a positive perception of HCPs’ own role in implementing LIs, the content or structure of LIs and HCPs’ positive attitude towards LIs. CONCLUSIONS: Multiple individual and environmental factors influence the implementation of LIs by HCPs in patients with hip and/or knee OA. The resulting overview of barriers and facilitators can guide future research on the implementation of LIs within OA care. To investigate whether factor frequency is related to the relevance of each domain, further research should assess the relative importance of the identified factors involving all relevant disciplines of primary and secondary HCPs. PROSPERO REGISTRATION NUMBER: CRD42019129348

Exploring patient satisfaction after operative and nonoperative treatment for midshaft clavicle fractures:a focus group analysis

Background: There is no consensus on the optimal treatment for displaced midshaft clavicle fractures. Several studies indicate superior patient satisfaction in favour of operative reconstruction. It is unknown what drives superior satisfaction in this treatment group. The aim of this study was to explore patient satisfaction and identify contributors to patient satisfaction after operative and nonoperative treatment for displaced midshaft clavicle fractures in adults using a focus group approach. Methods: Four face-to-face and two web-based focus groups were hosted. A total of 24 participants who were treated nonoperatively (n = 14) or operatively (n = 10) agreed to participate. Participants were selected using purposive sampling, ensuring variation in gender, age, treatment complications and outcomes. A question script was developed to systematically explore patient expectations, attitudes and satisfaction with different dimensions of care. All focus groups were voice-recorded and transcribed at verbatim. Thematic analysis was conducted on all face-to-face and web-based transcripts. Results: The main emerging themes across treatment groups were; need for more information, functional recovery, speed of recovery and patient-doctor interaction. There was no difference in themes observed between operative and nonoperative focus groups. The lack of information was the most important complaint in dissatisfied patients. Conclusion: Our study shows that informing patients about their injury, treatment options and expectations for recovery is paramount for overall patient satisfaction after treatment for a displaced midshaft clavicle fracture. Level of evidence: Level III, focus group study. </p

Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant

We present observations of 10 type Ia supernovae (SNe Ia) between 0.16 < z < 0.62. With previous data from our High-Z Supernova Search Team, this expanded set of 16 high-redshift supernovae and 34 nearby supernovae are used to place constraints on the Hubble constant (H_0), the mass density (Omega_M), the cosmological constant (Omega_Lambda), the deceleration parameter (q_0), and the dynamical age of the Universe (t_0). The distances of the high-redshift SNe Ia are, on average, 10% to 15% farther than expected in a low mass density (Omega_M=0.2) Universe without a cosmological constant. Different light curve fitting methods, SN Ia subsamples, and prior constraints unanimously favor eternally expanding models with positive cosmological constant (i.e., Omega_Lambda > 0) and a current acceleration of the expansion (i.e., q_0 < 0). With no prior constraint on mass density other than Omega_M > 0, the spectroscopically confirmed SNe Ia are consistent with q_0 <0 at the 2.8 sigma and 3.9 sigma confidence levels, and with Omega_Lambda >0 at the 3.0 sigma and 4.0 sigma confidence levels, for two fitting methods respectively. Fixing a ``minimal'' mass density, Omega_M=0.2, results in the weakest detection, Omega_Lambda>0 at the 3.0 sigma confidence level. For a flat-Universe prior (Omega_M+Omega_Lambda=1), the spectroscopically confirmed SNe Ia require Omega_Lambda >0 at 7 sigma and 9 sigma level for the two fitting methods. A Universe closed by ordinary matter (i.e., Omega_M=1) is ruled out at the 7 sigma to 8 sigma level. We estimate the size of systematic errors, including evolution, extinction, sample selection bias, local flows, gravitational lensing, and sample contamination. Presently, none of these effects reconciles the data with Omega_Lambda=0 and q_0 > 0.Comment: 36 pages, 13 figures, 3 table files Accepted to the Astronomical Journa

Supernova Limits on the Cosmic Equation of State

We use Type Ia supernovae studied by the High-Z Supernova Search Team to constrain the properties of an energy component which may have contributed to accelerating the cosmic expansion. We find that for a flat geometry the equation of state parameter for the unknown component, alpha_x=P_x/rho_x, must be less than -0.55 (95% confidence) for any value of Omega_m and is further limited to alpha_x<-0.60 (95%) if Omega_m is assumed to be greater than 0.1 . These values are inconsistent with the unknown component being topological defects such as domain walls, strings, or textures. The supernova data are consistent with a cosmological constant (alpha_x=-1) or a scalar field which has had, on average, an equation of state parameter similar to the cosmological constant value of -1 over the redshift range of z=1 to the present. Supernova and cosmic microwave background observations give complementary constraints on the densities of matter and the unknown component. If only matter and vacuum energy are considered, then the current combined data sets provide direct evidence for a spatially flat Universe with Omega_tot=Omega_m+Omega_Lambda = 0.94 +/- 0.26 (1-sigma).Comment: Accepted for publication in ApJ, 3 figure

Hubble Space Telescope and Ground-Based Observations of Type Ia Supernovae at Redshift 0.5: Cosmological Implications

We present observations of the Type Ia supernovae (SNe) 1999M, 1999N, 1999Q, 1999S, and 1999U, at redshift z~0.5. They were discovered in early 1999 with the 4.0~m Blanco telescope at Cerro Tololo Inter-American Observatory by the High-z Supernova Search Team (HZT) and subsequently followed with many ground-based telescopes. SNe 1999Q and 1999U were also observed with the Hubble Space Telescope. We computed luminosity distances to the new SNe using two methods, and added them to the high-z Hubble diagram that the HZT has been constructing since 1995. The new distance moduli confirm the results of previous work. At z~0.5, luminosity distances are larger than those expected for an empty universe, implying that a ``Cosmological Constant,'' or another form of ``dark energy,'' has been increasing the expansion rate of the Universe during the last few billion years.Comment: 68 pages, 22 figures. Scheduled for the 01 February 2006 issue of Ap.J. (v637