Objectives: Although some reports have shown a change in gait motion in cervical myelopathy patients using a three-dimensional (3D) gait analysis system, there has been no musculoskeletal modeling parameters investigating; muscle-tendon lengths (MTL) and velocity (MTV). This study aimed to investigate musculoskeletal modeling parameters of gait motion in cervical myelopathy patients.
Design: Subjects were 42 patients with cervical myelopathy classified as to its severity using the Japan Orthopaedic Association score excluding the upper extremity items: group 1 ( >10 points); group 2 (7-9 points); and group 3 (< 6 points), and 40 healthy volunteers (controls). A 3D gait analysis system (VICON 370) was used to obtain the spatiotemporal, kinematic, and kinetic parameters . The changes in MTL during gait were calculated using musculoskeletal modeling software (SIMM Gait), which calculates the MTL (using a Hill-type model) from changes in the main muscle based on joint motion recorded using the Vicon Clinical Manager. MTL was calculated as the distance along the modeled path of the adductor longus, rectus femoris, the biceps femoris, the gastrocnemius, and anterior tibialis between the muscle’s origin and insertion. MTV were estimated by computing the numerical derivative of the MTL data with respect to time.
Results: Genu recurvatum, deteriorated lower-extremity joint motion, and MTV were observed in group 3. MTV of the long head of the biceps femoris in controls, group 1 and 2 showed a bimodal waveform in the negative direction during the initial contact and pre-swing phases, whereas these characteristics were not present in group 3.
Conclusions: The strategies of MTV of the biceps femoris during gait motion in severe cervical myelopathy patients were different from those of the normal gait pattern. The imbalance between agonist and antagonist muscle tissue during gait could be involved in the occurrence of genu recurvatum.
Ippei Kitade– Division of Rehabilitation Medicine, University of Fukui Hospital
Hideaki Nakajima– Department of Orthopaedic Surgery, Fukui University
Ai Takahashi– Division of Rehabilitation Medicine, Fukui University
Shuji Watanabe– Department of Orthopaedic Surgery, Fukui University
Mayumi Matsumura– Division of Rehabilitation Medicine, University of Fukui Hospital
Seiichiro Shimada– Division of Rehabilitation Medicine, University of Fukui Hospital
Akihiko Matsumine– Department of Orthopaedic Surgery, Fukui University