Three noteworthy papers from unique study areas are highlighted in this month's journal. In the first example, Rowan et al. investigated varying modes of prescribed exercise for the prevention of type 2 diabetes. An important aspect of this study was the targeted recruitment of individuals with prediabetes who were not highly active. The level of supervision by qualified exercise professionals throughout the randomly assigned intervention allowed for intensity goals to be met within each session and for proper/timely progression of exercise intensity. The findings revealed a high degree of support for both continuous moderate intensity and/or intermittent high-intensity exercise as effective strategies to improve glycemic control, body composition, and physiological fitness among persons with prediabetes.
Next, I refer you to Davis and colleagues who examined cholesterol levels in synovial fluid from patients with and without rotator cuff tears. Synovial fluid cholesterol levels have been investigated in the past, but only in cadavers or in patients with inflammatory joint disease. This study compared serum and synovial fluid cholesterol levels in patients with no prior diagnosis of high cholesterol. Their results revealed no significant differences in any lipid values between patients with, versus without a rotator cuff tear. However, they did identify a consistent synovial fluid to serum cholesterol ratio, which is arguably the greatest novelty of the study. In retrospect, it would have been beneficial to include patients with a diagnosis of high cholesterol, although there were good reasons for excluding them in the current study.
Finally, Flaxman and coworkers used internal joint moments to investigate the functional roles of knee joint muscles. Sporting maneuvers expose the knee joint to large torsional loads as we rapidly decelerate, change direction or isometrically brace against an opponent, yet our major knee joint muscles are generally described as either flexors or extensors. Flaxman et al. used an innovative reductionist approach to assess the complex roles the leg muscles actually play. Participants modulated ground reaction forces while weight bearing to elicit combinations of shear and torsional loads at the ankle, knee, and hip. They determined that 7 of 10 muscles activated to support the knee against rotational and frontal plane loads, while the vastii muscle stiffened the joint in all loading directions to allow biarticular muscles to modulate ground reaction force magnitude and direction. This study questions the role of lower limb muscles and how they may protect the joint against injury inducing moments.
L. Bruce Gladden
School of Kinesiology