Motion‐derived coordinate systems reduce inter‐subject variability of elbow flexion kinematics

Abstract

The selection of a joint coordinate system affects the outcome of motion pathways. We developed coordinate systems for the ulna and humerus, which are generated from upper extremity motion. These Motion-Derived Coordinate Systems (CS) were compared to traditional Anatomy-Derived CS created using surface digitizations of anatomical features. Within-subject repeatability of creating MotionDerived CS was quantified. In vitro elbow flexion was generated in the gravity-dependent position using an active upper extremity motion simulator. Kinematic pathways of those motions were calculated in terms of valgus angulation and internal rotation of the ulna relative to the humerus, using both CS. The method of creating Motion-Derived CS was highly repeatable-less than 0.5 mm and 18 for all coordinate directions measured. Inter-subject variability of active flexion pathways was reduced with Motion-Derived CS compared to AnatomyDerived CS ( p < 0.05). The decrease in inter-subject kinematic variability when using Motion-Derived CS may increase the statistical power of biomechanical studies and allow for reduced sample sizes. This minimally invasive method, which also determines the elbow flexion and forearm rotation axes and center of the capitellum, may also be applicable in computer-navigated surgery of the upper limb. ß

The effect of radial head implant shape on radiocapitellar kinematics during in vitro forearm rotation

“…7 For the humerus, the capitellum surface and the trochlear sulcus were traced, and a point was digitized in the center of the humeral shaft at the mid-diaphysis. The capitellum was sphere fit, the trochlear sulcus was circle fit, and their centers were calculated.…”

Development and validation of a computational multibody model of the elbow joint

“…The approximate position of the humerus, ulna, and radius coordinate system are also indicated. The definition of the local elbow coordinate systems were obtained from Ferreira et al (2011) ,and Morrey and Chao (1976 3.4. Stiffness parameters for interosseous membrane.…”

“…The contact parameters used for this study are shown in Table 3.5. Local coordinate systems for each bone segment were created as described by Ferreira et al (2011) and Morrey and Chao (1976) to measure the segment motion of the model (Fig. 3.10).…”

“…As a result, for the situations where calculating bone deformation or stress-strain computations are not the choice, multibody modeling could be an appealing option. Many researchers have applied multibody models for specific applications such as predicting joint stability, joint contact areas and pressure, ligament functions, muscle contributions to joint moments, body segment motion, and menisci effect in the knee (Donahue, Hull, Rashid, & Jacobs, 2002;Ferreira, King, & Johnson, 2011;Fisk & Wayne, 2009;Guess, 2012;Guess, Liu, Bhashyam, & Thiagarajan, 2013;Guess et al, 2010;Stylianou, Guess, & Cook, 2012;Zielinska & Donahue, 2006).…”

A Refined Technique to Calculate Finite Helical Axes From Rigid Body Trackers

“…Challenges also still remain in determining accurate FHAs for investigations of joint kinematics due to inherent tracker error and vibration [8], One available technique to improve the calculated FHAs is the use of a moving window analysis [11,12]. Crawford [11] suggested that an arbitrary window size of ±10 data points spanning each FHA would reduce error; however, this window size may be ineffective for rapid movements or those that have inconsistent angular velocity.…”