To be able to assess the biomechanical and functional effects of ankle injury and disease it is necessary to characterise healthy ankle kinematics. Due to the anatomical complexity of the ankle, it is difficult to accurately measure the Tibiotalar and Subtalar joint angles using traditional marker-based motion capture techniques. Biplane Video X-ray (BVX) is an imaging technique that allows direct measurement of individual bones using high-speed, dynamic X-rays. The objective is to develop an in-vivo protocol for the hindfoot looking at the tibiotalar and subtalar joint during different activities of living. A bespoke raised walkway was manufactured to position the foot and ankle inside the field of view of the BVX system. Three healthy volunteers performed three gait and step-down trials while capturing Biplane Video X-Ray (125Hz, 1.25ms, 80kVp and 160 mA) and underwent MR imaging (Magnetom 3T Prisma, Siemens) which were manually segmented into 3D bone models (Simpleware Scan IP, Synopsis). Bone position and orientation for the Talus, Calcaneus and Tibia were calculated by manual matching of 3D Bone models to X-Rays (DSX Suite, C-Motion, Inc.). Kinematics were calculated using MATLAB (MathWorks, Inc. USA). Pilot results showed that for the subtalar joint there was greater range of motion (ROM) for Inversion and Dorsiflexion angles during stance phase of gait and reduced ROM for Internal Rotation compared with step down. For the tibiotalar joint, Gait had greater inversion and internal rotation ROM and reduced dorsiflexion ROM when compared with step down. The developed protocol successfully calculated the in-vivo kinematics of the tibiotalar and subtalar joints for different dynamic activities of daily living. These pilot results show the different kinematic profiles between two different activities of daily living. Future work will investigate translation kinematics of the two joints to fully characterise healthy kinematics.
Several authors have used 3D motion analysis to measure upper limb kinematics, but none have focused solely on wrist movements, in six degrees of freedom, during activities of daily living (ADL). This study aimed to determine the role of the different planar wrist movements during three standardised tasks, which may be affected by surgical procedures. Nine volunteers (age range 22-45) were recruited and each participant performed three simulated ADLs: using a door lever, a door knob and opening/closing a jam jar. The ADLs were simulated using a work-sim kit on an isokinetic dynamometer. Motion analysis was performed by a 10-camera Oqus system (Qualisys Medical AB, Gothenburg, Sweden). All raw kinematic data were exported to Visual3D (C-Motion Inc.), where the biomechanical model was defined and joint kinematics calculated. Table 1 shows a similar range of radial-ulnar deviation and flexion-extension as previous studies. However a substantial amount of wrist rotation also occurred in all tasks. This was significantly greater when using the door lever compared with the door knob and jam jar tasks. Previous studies have stated that a negligible degree of rotation occurs at the wrist. This study found a maximum mean of 31.7 degrees of wrist rotation. This indicates that considerable rotational movement occurs at the wrist during certain functional tasks. Surgical approaches and clinical pathology may disrupt structures responsible for rotational stability. Further investigation of this rotational component of carpal movement during additional ADLs is proposed in both normal and clinical subjects, to explore the potential relationship between carpal surgery and rotational laxity.
When a hip is replaced using a posterior surgical approach, some of the external rotator muscles are divided. The aim of this study was to assess if this surgery has a long term affect on hip rotation during activities of daily living. An electromagnetic tracking system was used to assess hip movements during the following activities:- Activity 1. Picking an object of the floor in a straight leg stance. Activity 2. Picking an object of the floor when knees are flexed. Activity 3. Sitting on a chair. Activity 4. Putting on socks, seated, with the trunk flexed forward. Activity 5. Putting on socks, seated, with the legs crossed. Activity 6. Climbing stairs. Measurements were taken from 10 subjects with bilaterally normal hips, 10 patients with a large head hip replacement, 10 patients with a resurfacing head and 10 patients with a small head hip replacement. All the hip replacement patients were at least 6 months post-op, with an asymptomatic contra-lateral native hip for comparison. Sensors were attached over the iliac crest and the mid-shaft of the lateral thigh. Data was collected as each activity was repeated 3 times. The tracker recorded hip rotation at 10 hertz, with an accuracy of 0.15 degree.AIM
METHODS
Shoulder pain limits range of motion (ROM) and reduces performing activities of daily living (ADL). Objective assessment of shoulder function could be of interest for diagnosing shoulder pathology or functional assessment of the shoulder after therapy. The feasibility of 2 wearable inertial sensors for functional assessment to differentiate between healthy subjects and patients with unilateral shoulder pathology is investigated using parameters as asymmetry. 75 subjects were recruited into this study and were measured for at least 8 h a day with the human activity monitor (HAM) sensor. In addition, patients completed the Disability of the Arm, Should and Hand (DASH) score and the Simple Shoulder Test (SST) score. From 39 patients with a variety of shoulder pathologies 24 (Age: 53.3 ± 10.5;% male: 62.5%) complete datasets were successfully collected. From the 36 age-matched healthy controls 28 (Age: 54.9 ± 5.8;% male = 57.1%) full datasets could be retrieved. Activity parameters were obtained using a self-developed algorithm (Matlab). Outcome parameters were gyroscope and accelerometry-based relative and absolute asymmetry scores (affected/unaffected; dominant/non-dominant) of movement intensity.Background
Methods
Introduction. Better functional outcomes, lower pain and better stability have been reported with knee designs which restore physiological knee kinematics. Also the ability of the TKA design to properly restore the physiological femoral rollback during knee flexion, has shown to be correlated with better restoration of the flexor/extensor mechanism, which is fundamental to the function of the human knee. The purpose of the study is to compare the kinematics of three different TKA designs, by evaluating knee motion during
