Reduced rate of knee extensor torque development in older adults with knee osteoarthritis is associated with intrinsic muscle contractile deficits

Abstract

We examined the effect of knee osteoarthritis on the rate of torque development (RTD) of the knee extensors in older adults with advanced-stage knee osteoarthritis (OA; n=15) and recreationally-active controls (n=15) of similar age, sex and health status, as well as the relationship between RTD and the size and contractility of single muscle fibers. OA participants had lower RTD when expressed in absolute terms (Nm/ms). There were sex differences in peak RTD (P<0.05), with greater RTD in men, but no group by sex interaction effects for any variables. The lower RTD in OA versus controls was not explained by variation between groups in the fiber type admixture of the muscle, and was mitigated when RTD was normalized to peak torque (PT). In knee OA volunteers, we found strong correlations between the RTD expressed relative to PT and the velocity of contraction of single myosin heavy chain (MHC) I and IIA/X muscle fibers (r=0.652 and 0.862; both P<0.05) and power output of MHC I fibers (r=0.642; P<0.05). In controls, RTD relative to PT was related to fiber cross-sectional area of MHC IIA/X fibers (r=0.707; P<0.05), but not measures of single fiber contractile performance. To our knowledge, these results represent the first demonstration that variation in whole muscle contractile kinetics in patients with advanced-stage knee osteoarthritis and healthy older adults is related, in part, to the size and function of single muscle fibers.

Men and Women Demonstrate Differences in Early Functional Recovery After Total Knee Arthroplasty

“…52 Aside from the importance of muscle power output in determining lower extremity function in older adults, 53 we have recently shown that contractile velocity in fast-twitch fibers is a strong determinant of the whole muscle rate of force development in men and women with knee OA. 54 Rate of force development is a measure that we and others have shown is acutely reduced following TKA and predicts decreased function. 55,56 Sex differences in myofilament adaptations could also help explain why women maintain isometric quadriceps strength compared to men after TKA.…”

Contribution of Neuromuscular Factors to Quadriceps Asymmetry After Anterior Cruciate Ligament Reconstruction

“…The RTD was calculated from the onset of torque to peak torque every 10 milliseconds and averaged across the trial (RTD ¼ [(Dtorque / Dtime) / mass]). 20,30 The TTP was calculated (TTP ¼ time of peak torque -time of onset of torque) for both isometric and isokinetic data. 15 A representation of how the isometric and isokinetic data were analyzed is shown in Figures 1 and 2, respectively.…”

Muscle Function during Selected Weight-Bearing Activities in Adults with Knee Osteoarthritis- A Narrative Overview

“…In addition, muscle endurance rather than strength may be a potent determinant of abnormal joint loading [31] . Alignment and muscle action in knee osteoarthritis [36] Differences in muscle activity between cases with osteoarthritis and healthy cases [7,34,78] Hamstring-quadriceps muscle balance in knee osteoarthritis [9,65] Impact of cyclic concentric and eccentric submaximal muscle loading [5] Interlimb symmetry and co-contraction in knee osteoarthritis [61] Knee muscle activation during sit-to-stand in knee osteoarthritis [26,43,86] Knee muscle activation during walking [35,39,41,57,60,64,69,72,73,74,75] Knee extensor power and mobility in knee osteoarthritis [30] Morphological changes in vastus medialis in knee osteoarthritis [10,22] Motor unit properties in knee osteoarthritis [49] Motor control/dysfunction in knee osteoarthritis [25,37,54] Muscle afferent neurons and osteoarthritis [24] Muscle contractile deficits [9,20,85] Muscle cross-sectional areas and knee abnormalities [23] Muscle inflammation and walking [19,27] Muscle strength and inflammation in knee osteoarthritis in older women [81] Muscle strength and proprioception [18] Neuromuscular adaptations during stepping [16] Neuromuscular ...…”

“…In addition to the aforementioned observations, muscle power [42] , and eccentric rather than concentric muscle coactivation [43] , as well as pain and a variety of muscular abnormalities may accompany osteoarthritic joint damage [47][48][49][50] , and/or may independently or collectively heighten activity limitations and central nervous system responses that foster the development of the disease [51][52][53] , but these factors have not commonly been examined in the context of the studies reported here. This is surprising given that subjects with knee osteoarthritis do present with significant muscle impairments that affect physical function [54] as well as wide variations in whole muscle contractile kinetics [55] . Rate of force development [13] , and effusion, a determinant of muscle function in knee osteoarthritis, is also not well correlated with findings in the context of the present topic [45] .…”

“…In fact, this cursory analysis revealed a very broad spectrum of muscular mechanisms possibly involved in the osteoarthritisdisability cycle, including: muscle strength deficits [14,15] , abnormal muscle activation patterns [16] , abnormal muscle loading forces [17] , proprioception problems [18] , muscle inflammation [19] , deficits in muscle rate of torque development [20] , abnormally coordinated muscle function [21] muscle structural abnormalities [22] , muscle flexor/ extensor imbalances [23] , and problems attributed to impaired muscle afferent activity [24] . To discern if any of these factors are associated with functional activities of daily living, and if so in what way, only studies that examined muscle function in the context of functional activities in knee osteoarthritis cohorts who had no surgical history were examined.…”