We read the recent manuscript by Kal et al.1 ‘Explicit motor learning interventions are still relevant for ACL injury rehabilitation: do not put all your eggs in the implicit basket‘ with great interest. The authors did a commendable job summarizing the current literature and we highly respect them for being critical, to foster academic discussions to move science forward. We do however have some concerns regarding the methodology and interpretations made by the authors.
LINK
Background: Retention of movement technique is crucial in anterior cruciate ligament (ACL) injury pre- vention programs. It is unknown if specific instructions or video instructions result in changes in kine- matic and kinetic measures during a relatively short training session, and in a retention test one week later.Hypothesis/Purpose: The purpose was to determine the effects of verbal external focus (EF), verbal inter- nal focus (IF) and video instructions (VI) on landing technique (i.e. kinematics and kinetics) during train- ing and retention.Study Design: Randomized Controlled Trial.Methods: This study compared verbal EF, verbal IF, VI and CTRL group. Forty healthy athletes were assigned to the IF (n=10), EF (n=10), VI (n=10) or CTRL group (n=10). A jump-landing task was per- formed as a baseline, followed by two training blocks (TR1 and TR2) and a post test. Group specific instruc- tions were offered in TR1 and TR2. In addition, subjects in the IF, EF and VI groups were free to ask for feedback after every jump in TR1 and TR2. One week later, a retention test was conducted without specific instructions or feedback. Kinematics and kinetics were captured using an 8-camera motion analysis system.Results: Males and females in the EF and VI instruction group showed beneficial results during and after the training session, in terms of improved landing technique. Retention was achieved after only a short training session.Conclusion: ACL injury prevention programs should include EF and/or VI instructions to improve kine- matics and kinetics and achieve retention.Level of Evidence: 3bKey words: Injury prevention, motor learning, movement technique, retention
Research of non-contact anterior cruciate ligament (ACL) inj1ury risk aims to identify modifiable risk factors that are linked to the mechanisms of injury. Information from these studies is then used in the development of injury prevention programmes. However, ACL injury risk research often leans towards methods with three limitations: 1) a poor preservation of the athlete-environment rela- tionship that limits the generalisability of results, 2) the use of a strictly biomechanical approach to injury causation that is incom- plete for the description of injury mechanisms, 3) and a reductionist analysis that neglects profound information regarding human movement. This current opinion proposes three principles from an ecological dynamics perspective that address these limitations. First, it is argued that, to improve the generalisability of findings, research requires a well-preserved athlete-environment relation- ship. Second, the merit of including behaviour and the playing situation in the model of injury causation is presented. Third, this paper advocates that research benefits from conducting non- reductionist analysis (i.e., more holistic) that provides profound information regarding human movement. Together, these princi- ples facilitate an ecological dynamics approach to injury risk research that helps to expand our understanding of injury mechan- isms and thus contributes to the development of preventative measures.
In dit project verricht het lectoraat Familiebedrijven van Hogeschool Windesheim samen met de Hogeschool Utrecht, Hogeschool van Amsterdam, CUMELA, de Jong & Laan en MKB familiebedrijven praktijkgericht onderzoek naar financiering en besluitvorming bij MKB familiebedrijven. Nu banken vanwege de economische crisis terughoudender zijn geworden in kredietverlening en hun financieringseisen hebben verzwaard, zijn meer bedrijven aangewezen op eigen middelen en familiekapitaal. Vormen van zelf-financiering worden steeds belangrijker om groei en continuïteit van MKB familiebedrijven te waarborgen. Met name bij de overdracht van kapitaalintensieve MKB familiebedrijven worden complexe financieringsconstructies bedacht om de overname mogelijk te maken. Vaak wordt hierbij onvoldoende nagedacht over het onderscheid tussen de verschillende rollen die familieleden kunnen hebben als ze met hun vermogen in het bedrijf zitten (eigenaar of andere vermogensverschaffer, familielid, directielid, werknemer). Hierdoor kan onduidelijkheid ontstaan over onderwerpen zoals besluitvorming, rendement op vermogen, zeggenschap en beloningsstructuren, waardoor op termijn conflicten kunnen ontstaan. Daarnaast kan de besturing van ondernemingen door de verschillende belangen van vermogensverschaffers in negatieve zin worden beïnvloed en kan dit (op termijn) de continuïteit, wendbaarheid en groei van ondernemingen in gevaar brengen. Zowel in de praktijk als in het onderzoek ontbreekt het aan kennis over hoe met deze problematiek kan worden omgegaan. Dit project heeft daarom tot doel om samen met de projectpartners nieuwe kennis te ontwikkelen rond zelf-financiering en besluitvorming in MKB familiebedrijven. Door middel van ontwerpgericht praktijkonderzoek wordt bestaande en nieuwe kennis over de rol van zelf-financiering en de positie van eigenaren omgezet in oplossingsrichtingen ter verbetering van de besluitvorming in MKB familiebedrijven. Door het monitoren van de uitgevoerde interventies zal worden vastgesteld of de oplossingsrichtingen in de praktijk werken. De kennis die uit dit project voortkomt beoogt daarmee het handelingsvermogen van eigenaren en directieleden te vergroten en zelf-financiering als mogelijke financieringsbron effectiever te maken.
The anterior cruciate ligament (ACL) is a strong rope-like tissue which connects the femur to the tibia in the knee joint. Its function is to provide structural stability to the knee while preventing unnatural forward movement of the tibia relative to the femur. Acute complete ACL ruptures during movements like knee hyperextension or sudden changes of direction (pivoting) damage two entities: the ligament itself and its nerve connections to the posterior tibial nerve (PTN). PTN innervation in the ACL is essential for: a) proprioception (e.g. perception of position and movement/acceleration experienced by the ligament), and b) stability of the knee joint. Upon ACL rupture, the orthopedic surgeon reconstructs the ACL with a graft from the hamstring, patellar or quadriceps tendon. After the surgery, the goal is to regain neuromuscular control and dynamic stabilization during rehabilitation as soon as possible for a quick return to sports and daily activities. However, surgeons are not able to reconstruct the nerve gap between the PTN and the grafted ligament due to the microscopic size of the innervation in the ACL. Not linking the PTN to the graft creates a disconnection between the knee joint and the spinal cord. To mitigate these disadvantages in ACL surgery, this study focuses on activating the growth of proprioception nerve endings using a ligament loaded with growth factors (neurotrophins). We hypothesize that neurotrophins will activate proprioceptive fibers of neurons close to the ACL. We describe graft fabrication steps and in vitro experiments to expand on the regeneration capacity of a commercially available ACL-like synthetic ligament called LARS. The results will bring the ACL regeneration field closer to having a graft that can aid patients in regaining mobility and stability during locomotion and running, confidence in the strength of the knee joint, and quick return to sports.
The utilization of drones in various industries, such as agriculture, infrastructure inspection, and surveillance, has significantly increased in recent years. However, navigating low-altitude environments poses a challenge due to potential collisions with “unseen” obstacles like power lines and poles, leading to safety concerns and equipment damage. Traditional obstacle avoidance systems often struggle with detecting thin and transparent obstacles, making them ill-suited for scenarios involving power lines, which are essential yet difficult to perceive visually. Together with partners that are active in logistics and safety and security domains, this project proposal aims at conducting feasibility study on advanced obstacle detection and avoidance system for low-flying drones. To that end, the main research question is, “How can AI-enabled, robust and module invisible obstacle avoidance technology can be developed for low-flying drones? During this feasibility study, cutting-edge sensor technologies, such as LiDAR, radar, camera and advanced machine learning algorithms will be investigated to what extent they can be used be to accurately detect “Not easily seen” obstacles in real-time. The successful conclusion of this project will lead to a bigger project that aims to contribute to the advancement of drone safety and operational capabilities in low-altitude environments, opening new possibilities for applications in industries where low-flying drones and obstacle avoidance are critical.
