Assessment of elbow joint kinematics in passive motion by electromagnetic motion tracking

Abstract

Summary:This research provides a detailed analysis of the kinematics of passive elbow motion. I1 quantifies how closely humeroulnar kinematics approximates rotation around a fixed axis. The results are clinically relevant for emerging treatment modalities that impose an artificial hinge to the elbow joint, such as total elbow arthroplasty and articulated external fixation. In a cadaveric study of seven specimens. we quantified ulnar rotation around the humerus in terms of instantaneous screw displacement axes calculated from electromagnetic motion-tracking source data. This methodology enabled description of the complex excursion of the elbow axis in terms of translation and orientation changes of the screw displacement axes over the range of motion. Furthermore, we analyzed the envelope of joint laxity for elbow motion under applied small varus and valgus moments. In addition, radiographic landmarks of clinical utility for axis location were evaluated by visualizing the elbow's radiographic appearance when viewed from along the calculated best-fit (average) rotation axis. Over the normal range of elbow motion, the screw displacement axis varied 2.6-5.7" in orientation and 1.4-2.0 mm in translation. All instantaneous rotation axes nearly intersected on the medial facet of the Irochlca. The breadth of the envelope of varus-valgus joint laxity was greatest within the initial 40" of flexion and decreased by a factor of approximately two for flexion angles exceeding 100".

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

“…8 In particular, the helical axis, also known as Screw Displacement Axis (SDA), method has been widely reported in the biomechanics literature and shown to accurately determine the true elbow flexion axis. [9][10][11][12] It has also been shown that the SDA method can be used to calculate the forearm rotation axis, and that it intersects with the flexion axis SDA at the radiocapitellar joint. 12 This provides a convenient way to locate the origin of a CS, and we theorized that these characteristics could be used to create CS based on motion of the upper extremity, hereafter referred to as Motion-Derived CS.…”

Elbow Brace Promotes Postoperative Rehabilitation of Osteochondral Graft in Young Athletes with Osteochondritis Dissecans of the Humeral Capitellum

“…The elbow brace may interfere with normal screw displacement as well as valgus/varus movement of the elbow joint. Bottlang et al 7) stated that the screw displacement axis varied over a relatively small range. For practical purposes, wearing an elbow brace protects the collateral ligament as well as the osteochondral graft from excess stress during rehabilitation.…”

Neuro-robotics Paradigm for Intelligent Assistive Technologies

“…The passive mechanism provides A FE with three passive DOFs, which allow the NEUROExos axis to trace the same double conic frustum traced by the human axis (Bottlang et al, 1998;Bottlang et al, 2000;Duck et al, 2003). First, A FE can rotate in the frontal plane of an angle γ f = ±15°.…”