BACKGROUND: Instability of the knee joint during gait is frequently reported by patients with knee osteoarthritis or an anterior cruciate ligament rupture. The assessment of instability in clinical practice and clinical research studies mainly relies on self-reporting. Alternatively, parameters measured with gait analysis have been explored as suitable objective indicators of dynamic knee (in)stability.RESEARCH QUESTION: This literature review aimed to establish an inventory of objective parameters of knee stability during gait.METHODS: Five electronic databases (Pubmed, Embase, Cochrane, Cinahl and SPORTDiscuss) were systematically searched, with keywords concerning knee, stability and gait. Eligible studies used an objective parameter(s) to assess knee (in)stability during gait, being stated in the introduction or methods section. Out of 10717 studies, 89 studies were considered eligible.RESULTS: Fourteen different patient populations were investigated with kinematic, kinetic and/or electromyography measurements during (challenged) gait. Thirty-three possible objective parameters were identified for knee stability, of which the majority was based on kinematic (14 parameters) or electromyography (12 parameters) measurements. Thirty-nine studies used challenged gait (i.e. external perturbations, downhill walking) to provoke knee joint instability. Limited or conflicting results were reported on the validity of the 33 parameters.SIGNIFICANCE: In conclusion, a large number of different candidates for an objective knee stability gait parameter were found in literature, all without compelling evidence. A clear conceptual definition for dynamic knee joint stability is lacking, for which we suggest : "The capacity to respond to a challenge during gait within the natural boundaries of the knee". Furthermore biomechanical gait laboratory protocols should be harmonized, to enable future developments on clinically relevant measure(s) of knee stability during gait.
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Knee joint instability is frequently reported by patients with knee osteoarthritis (KOA). Objective metrics to assess knee joint instability are lacking, making it difficult to target therapies aiming to improve stability. Therefore, the aim of this study was to compare responses in neuromechanics to perturbations during gait in patients with self-reported knee joint instability (KOA-I) versus patients reporting stable knees (KOA-S) and healthy control subjects.Forty patients (20 KOA-I and 20 KOA-S) and 20 healthy controls were measured during perturbed treadmill walking. Knee joint angles and muscle activation patterns were compared using statistical parametric mapping and discrete gait parameters. Furthermore, subgroups (moderate versus severe KOA) based on Kellgren and Lawrence classification were evaluated.Patients with KOA-I generally had greater knee flexion angles compared to controls during terminal stance and during swing of perturbed gait. In response to deceleration perturbations the patients with moderate KOA-I increased their knee flexion angles during terminal stance and pre-swing. Knee muscle activation patterns were overall similar between the groups. In response to sway medial perturbations the patients with severe KOA-I increased the co-contraction of the quadriceps versus hamstrings muscles during terminal stance.Patients with KOA-I respond to different gait perturbations by increasing knee flexion angles, co-contraction of muscles or both during terminal stance. These alterations in neuromechanics could assist in the assessment of knee joint instability in patients, to provide treatment options accordingly. Furthermore, longitudinal studies are needed to investigate the consequences of altered neuromechanics due to knee joint instability on the development of KOA.
INTRODUCTION: To provide a state of the art on diagnostics, clinical characteristics, and treatment of paediatric generalised joint hypermobility (GJH) and joint hypermobility syndrome (JHS).METHOD: A narrative review was performed regarding diagnostics and clinical characteristics. Effectiveness of treatment was evaluated by systematic review. Searches of Medline and Central were performed and included nonsymptomatic and symptomatic forms of GJH (JHS, collagen diseases).RESULTS: In the last decade, scientific research has accumulated on all domains of the ICF. GJH/JHS can be considered as a clinical entity, which can have serious effects during all stages of life. However research regarding the pathological mechanism has resulted in new potential opportunities for treatment. When regarding the effectiveness of current treatments, the search identified 1318 studies, from which three were included (JHS: n = 2, Osteogenesis Imperfecta: n = 1). According to the best evidence synthesis, there was strong evidence that enhancing physical fitness is an effective treatment for children with JHS. However this was based on only two studies.CONCLUSION: Based on the sparsely available knowledge on intervention studies, future longitudinal studies should focus on the effect of physical activity, fitness, and joint stabilisation. In JHS and chronic pain, the effectiveness of a multidisciplinary approach should be investigated.
