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Tendons transmit the muscle contraction forces to bones and drive joint movement throughout life. While extensive research have indicated the essentiality of mechanical forces on tendon development, a comprehensive understanding of the fundamental role of mechanical forces still needs to be impaerted. This scoping review aimed to summarize the current knowledge about the role of mechanical forces during the tendon developmental phase. The electronic database search using PubMed, performed in May 2023, yielded 651 articles, of which 16 met the prespecified inclusion criteria. We summarized and divided the methods to reduce the mechanical force into three groups: loss of muscle, muscle dysfunction, and weight‐bearing regulation. In contrast, there were few studies to analyze the increased mechanical force model. Most studies suggested that mechanical force has some roles in tendon development in the embryo to postnatal phase. However, we identified species variability and methodological heterogeneity to modulate mechanical force. To establish a comprehensive understanding, methodological commonality to modulate the mechanical force is needed in this field. Additionally, summarizing chronological changes in developmental processes across animal species helps to understand the essence of developmental tendon mechanobiology. We expect that the findings summarized in the current review serve as a groundwork for future study in the fields of tendon developmantal biology and mechanobiology. Key Findings: Recent mechano‐biological studies about tendon development have no consensus on the definition of mechanical force on the tendon. A clear definition of mechanical force based on species is needed to establish a comprehensive understanding of the role of mechanical force on tendon development. [ABSTRACT FROM AUTHOR]

Inflammatory cytokines released by synovium after trauma disturb the gene regulatory network and have been implicated in the pathophysiology of osteoarthritis. A mechanistic understanding of how aging perturbs this process can help identify novel interventions. Here, we introduced network paradigms to simulate cytokine‐mediated pathological communication between the synovium and cartilage. Cartilage‐specific network analysis of injured young and aged murine knees revealed aberrant matrix remodeling as a transcriptomic response unique to aged knees displaying accelerated cartilage degradation. Next, network‐based cytokine inference with pharmacological manipulation uncovered IL6 family member, Oncostatin M (OSM), as a driver of the aberrant matrix remodeling. By implementing a phenotypic drug discovery approach, we identified that the activation of OSM recapitulated an "inflammatory" phenotype of knee osteoarthritis and highlighted high‐value targets for drug development and repurposing. These findings offer translational opportunities targeting the inflammation‐driven osteoarthritis phenotype. [ABSTRACT FROM AUTHOR]

A recent study published in the Journal of Physiology examined the impact of aerobic exercise on microvascular health in post-menopausal women. The study found that older women who exercise experience fewer benefits, such as less angiogenesis, compared to younger women. The researchers investigated how aerobic exercise affected the metabolic response of skeletal muscle endothelial cells in recent postmenopausal females compared to late postmenopausal females. They found that the exercise program had positive effects on metabolic outcomes in the recent postmenopausal group, but not in the late postmenopausal group. The study also explored the role of estrogen-related receptor alpha (ORRα) in modulating the relationship between menopause and skeletal muscle microvasculature. The findings suggest that further research is needed to fully understand the impact of menopause on exercise outcomes and to explore other forms of exercise. [Extracted from the article]

Purpose: Identification of responders/non-responders to unsupervised therapeutic exercise represents a critical challenge towards establishment of tailored self-management at home. Focusing on visualized varus thrust during gait as a possible effect moderator, this study determined whether and how varus thrust influences the therapeutic effects of home-based quadriceps exercise in individuals at increased risk of, or with, established knee osteoarthritis., Methods: This study is a secondary subgroup analysis of a randomized controlled trial (n = 50). Varus thrust at baseline was assessed via recorded gait movie. Analysis of covariance and subsequent mediation analysis were used to determine whether and how varus thrust influences the therapeutic effect of home-based quadriceps exercise after adjustment for covariates. To address the possible distinct impact of varus thrust on unsupervised and supervised exercise, the results were cross-checked with previous supervised exercise cohort using a meta-analysis., Results: Individuals without varus thrust displayed greater and clinically meaningful pain-relief after exercise after adjustment for covariates. The greater pain-relief in individuals without varus thrust was attributed, at least partly, to an improvement in knee flexion range of motion. Notably, the meta-analysis revealed that unsupervised and supervised exercise programs induce consistent and clinically meaningful pain reduction in individuals without varus thrust., Conclusions: Varus thrust is a robust effect moderator of the pain reducing effect of quadriceps exercise. Further, greater pain reduction may be a function of improvement of knee flexion range of motion. These studies provide evidence that varus thrust assessment represents valuable approach to identify responders/non-responders to quadriceps exercise even for unsupervised protocol at their home environment., Competing Interests: Conflict of Interest and Funding Source: This study was supported in part by (1) a JSPS KAKENHI (Grant Number: 23H03308) from the Japan Society for the Promotion of Science (https://www.jsps.go.jp/) for HI., (Copyright © 2024 by the American College of Sports Medicine.)