An understanding of the alterations in articular cartilage following short and long term immobilization in humans is essential for the optimization of rehabilitation programs. Refined imaging techniques combined with state-of-the-art visualization tools could allow the systematical monitoring of articular cartilage morphology changes in immobilized humans.

Objective. To assess the effectiveness of isolated resistance training on arthritis symptoms, physical performance, and psychological function in people with knee osteoarthritis. Methods. A comprehensive systematic database search for randomized controlled trials was performed. Two reviewers independently assessed studies for potential inclusion. Study quality indicators, arthritis symptoms, muscle strength, functional performance, and psychological outcomes were extracted. The relative effect sizes (ES) were calculated with 95% confidence intervals. Results. Eighteen studies enrolling 2,832 subjects were reviewed; the mean cohort age range was 55-74 years. In general, the quality of the reviewed literature was moderately robust; on average, 8 out of 12 quality criteria were accounted for in the reviewed literature. Self-reported measures of pain, physical function, and performance, along with muscle strength (mean 17.4%), maximal gait speed and chair stand time, and balance improved significantly following resistance training in 56 -100% of studies where they were measured. Limitations included lack of data available for ES calculations and lack of adverse event and compliance reporting, particularly with regard to the actual training intensity versus the prescribed training intensity. Conclusion. Resistance training improved muscle strength and self-reported measures of pain and physical function in over 50 -75% of this cohort; 50 -100% of the studies reported a significant improvement in all but 1 performance-based physical function measure (walk time). The effects of resistance training on health-related quality of life and depression are yet to be confirmed. More research needs to be conducted to establish dose-response relationships and the effect of resistance training on long-term disability, disease pathology, and progression.

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Objective. Alterations in the morphologic, biochemical, and mechanical properties of cartilage occur after unloading and immobilization in animals. However, the findings have been inconsistent and it is unclear whether such changes also take place in humans. This study tested the hypothesis that progressive thinning of knee joint cartilage is observed after spinal cord injury.Methods. In this in vivo study, knee cartilage was assessed in patients with complete, traumatic spinal cord injury at 6 (n ‫؍‬ 9), 12 (n ‫؍‬ 11), and 24 months (n ‫؍‬ 6) after injury. Morphologic parameters of the knee cartilage (mean and maximum thickness as well as surface area) were computed from magnetic resonance imaging (MRI) data, and results were compared with those in young, healthy volunteers (n ‫؍‬ 9).Results. After 6 months of injury, the mean articular-cartilage thickness was significantly less in the patella and medial tibia (decrease of 10% and 16%, respectively; P < 0.05), but not in the lateral tibia (decrease of 10%), compared with the MRI findings in healthy volunteers. After 12 and 24 months of injury, the differences amounted to a reduction of 21% and 23%, respectively, in the patella, 24% and 25%, respectively, in the medial tibia, and 16% and 19%, respectively, in the lateral tibia. The changes were significant in all 3 surfaces of the spinal cord-injured joint cartilage (P < 0.05-0.01).Conclusion. Our data show, for the first time, that progressive thinning (atrophy) of human cartilage occurs in the absence of normal joint loading and movement. This may have important implications for patient management, in particular for spinal cord-injured patients and patients who are immobilized after surgery.

BackgroundThe effect of footwear on the gait of children is poorly understood. This systematic review synthesises the evidence of the biomechanical effects of shoes on children during walking and running.MethodsStudy inclusion criteria were: barefoot and shod conditions; healthy children aged ≤ 16 years; sample size of n > 1. Novelty footwear was excluded. Studies were located by online database-searching, hand-searching and contact with experts. Two authors selected studies and assessed study methodology using the Quality Index. Meta-analysis of continuous variables for homogeneous studies was undertaken using the inverse variance approach. Significance level was set at P < 0.05. Heterogeneity was measured by I2. Where I2 > 25%, a random-effects model analysis was used and where I2 < 25%, a fixed-effects model was used.ResultsEleven studies were included. Sample size ranged from 4-898. Median Quality Index was 20/32 (range 11-27). Five studies randomised shoe order, six studies standardised footwear. Shod walking increased: velocity, step length, step time, base of support, double-support time, stance time, time to toe-off, sagittal tibia-rearfoot range of motion (ROM), sagittal tibia-foot ROM, ankle max-plantarflexion, Ankle ROM, foot lift to max-plantarflexion, 'subtalar' rotation ROM, knee sagittal ROM and tibialis anterior activity. Shod walking decreased: cadence, single-support time, ankle max-dorsiflexion, ankle at foot-lift, hallux ROM, arch length change, foot torsion, forefoot supination, forefoot width and midfoot ROM in all planes. Shod running decreased: long axis maximum tibial-acceleration, shock-wave transmission as a ratio of maximum tibial-acceleration, ankle plantarflexion at foot strike, knee angular velocity and tibial swing velocity. No variables increased during shod running.ConclusionsShoes affect the gait of children. With shoes, children walk faster by taking longer steps with greater ankle and knee motion and increased tibialis anterior activity. Shoes reduce foot motion and increase the support phases of the gait cycle. During running, shoes reduce swing phase leg speed, attenuate some shock and encourage a rearfoot strike pattern. The long-term effect of these changes on growth and development are currently unknown. The impact of footwear on gait should be considered when assessing the paediatric patient and evaluating the effect of shoe or in-shoe interventions.