The influence of muscle load on tibiofemoral knee kinematics

Abstract

A comparative kinematics study was conducted on six cadaver limbs, comparing tibiofemoral kinematics in five conditions: unloaded, under a constant 130 N ankle load with a variable quadriceps load, with and without a simultaneous constant 50 N medial and lateral hamstrings load. Kinematics were described as translation of the projected centers of the medial (MFT) and lateral femoral condyles (LFT) in the horizontal plane of the tibia, and tibial axial rotation (TR) as a function of flexion angle. In passive conditions, the tibia rotated internally with increasing flexion to an average of À168 (range: À12/À208, SD ¼ 3.08). Between 0 and 408 flexion, the medial condyle translated forwards 4 mm (range: 0.8/5.5 mm, SD ¼ 2.5 mm), followed by a gradual posterior translation, totaling À9 mm (range: À5.8/ À18.5 mm, SD ¼ 4.9 mm) between 40-1408 flexion. The lateral femoral condyle translated posteriorly with increasing flexion completing À25 mm (range: À22.6 to À28.2 mm, SD ¼ 2.5 mm). Dynamic, loaded measurements simulating a deep knee bend were carried out in a knee rig. Under a fixed ankle load of 130 N and variable quadriceps loading, tibial rotation was inverted, mean TR Keywords: knee; kinematics; muscle loading; anterior cruciate ligament Knee kinematics are complex and intriguing and have been studied extensively. 1 The deduced model describes posterior translation of the femoral condyles relative to the tibia with increasing flexion. This translation is greater on the lateral than on the medial side, leading to relative internal tibial rotation. However, different methods reveal different patterns, and existing literature is not unanimous in describing ''normal'' knee kinematics. Differences can be attributed to intrinsic and extrinsic factors. Intrinsic factors relate to the interindividual differences. Most studies included small numbers of specimens, patients, or volunteers, so bias cannot be excluded, even with a normal distribution of anatomic features or kinematic patterns. Extrinsic factors include the experimental setup with differences in quadriceps force, hamstrings cocontraction, triceps surae cocontraction, loads, and mechanical constraints imposed on the joint. Also, the mathematical model used for describing knee kinematics will influence the results. [2][3][4][5] Studies describing passive or unloaded knee kinematics 6-12 should be differentiated from studies describing loaded kinematics. Loaded in vitro experiments typically use load frames, knee simulators, or robots where controlled loads are applied to the joint. [13][14][15][16][17][18][19][20][21][22][23][24][25] These experiments can use a feedback loop between ankle load and applied quadriceps force, but are arbitrary when it comes to cocontraction of important muscle groups. Loads exerted by cocontraction of hamstrings and triceps surae remain uncertain, which is reflected in the large range of applied loads use in kinematic experiments. 14,16,20,21,24,25 Loaded in vivo research uses MRI imaging, 10,26,27 roentgen stereophotogram...

Contact forces in several TKA designs during squatting: A numerical sensitivity analysis

“…experimental tests performed in a previous in-vitro analysis on cadaver legs (Innocenti et al, 2009a,b;Victor et al, 2009bVictor et al, , 2010.…”

“…The loaded squat was reproduced numerically, simulating an existing knee kinematics rig (Maletsky, 1999;Victor et al, 2009cVictor et al, , 2010 in terms of geometries, constraints, inputs and outputs. The simulated machine and its function and constraints are shown in Fig.…”

Decoupled Control for the Bicycling UGent Knee Rig: Design, Implementation, and Validation

“…Another difference with the OKR is that the UGKR not only controls the quadriceps force but also the hamstring forces. The latter have shown a considerable contribution to the knee kinematics [32].…”

“…A combination of both is often applied within the same simulator [22], [32], [33]. The Purdue knee simulator [22] is controlling five axes in order to impose squat motions, where the actuators can be controlled in either position or force mode.…”

Correlation between the Angle of Lateral Tibial Rotation and the Ratio of Medial and Lateral Hamstring Muscle Activities during Standing Knee Flexion

“…Victor et al 14) reported that the tibia was rotated more laterally with a 50-N lateral hamstring load than with a 50-N medial hamstring load in knee flexion experiments using cadavers. The medial hamstrings (semitendinosus and semimembranosus muscles) are inserted at the pes anserine tendon at the proximal anteromedial tibia (semitendinosus) and posterior surface of the medial condyle of the tibia (semimembranosus) 15) .…”