Intra-protocol repeatability and inter-protocol agreement for the analysis of scapulo-humeral coordination.

Multi-center clinical trials incorporating shoulder kinematics are currently uncommon. The absence of repeatability and limits of agreement (LoA) studies between different centers employing different motion analysis protocols has led to a lack dataset compatibility. Therefore, the aim of this work was to determine the repeatability and LoA between two shoulder kinematic protocols. The first one uses a scapula tracker (ST), the International Society of Biomechanics anatomical frames and an optoelectronic measurement system, and the second uses a spine tracker, the INAIL Shoulder and Elbow Outpatient protocol (ISEO) and an inertial and magnetic measurement system. First within-protocol repeatability for each approach was assessed on a group of 23 healthy subjects and compared with the literature. Then, the between-protocol agreement was evaluated. The within-protocol repeatability was similar for the ST ([Formula: see text] = 2.35°, [Formula: see text] = 0.97°, SEM = 2.5°) and ISEO ([Formula: see text] = 2.24°, [Formula: see text] = 0.97°, SEM = 2.3°) protocols and comparable with data from published literature. The between-protocol agreement analysis showed comparable scapula medio-lateral rotation measurements for up to 120° of flexion-extension and up to 100° of scapula plane ab-adduction. Scapula protraction-retraction measurements were in agreement for a smaller range of humeral elevation. The results of this study suggest comparable repeatability for the ST and ISEO protocols and between-protocol agreement for two scapula rotations. Different thresholds for repeatability and LoA may be adapted to suit different clinical hypotheses.

Ambulatory measurement of the scapulohumeral rhythm: intra- and inter-operator agreement of a protocol based on inertial and magnetic sensors.

To measure the scapulohumeral rhythm (SHR) in outpatient settings, the motion analysis protocol named ISEO (INAIL Shoulder and Elbow Outpatient protocol) was developed, based on inertial and magnetic sensors. To complete the sensor-to-segment calibration, ISEO requires the involvement of an operator for sensor placement and for positioning the patient's arm in a predefined posture. Since this can affect the measure, this study aimed at quantifying ISEO intra- and inter-operator agreement. Forty subjects were considered, together with two operators, A and B. Three measurement sessions were completed for each subject: two by A and one by B. In each session, the humerus and scapula rotations were measured during sagittal and scapular plane elevation movements. ISEO intra- and inter-operator agreement were assessed by computing, between sessions, the: (1) similarity of the scapulohumeral patterns through the Coefficient of Multiple Correlation (CMC(2)), both considering and excluding the difference of the initial value of the scapula rotations between two sessions (inter-session offset); (2) 95% Smallest Detectable Difference (SDD(95)) in scapula range of motion. Results for CMC(2) showed that the intra- and inter-operator agreement is acceptable (median≥0.85, lower-whisker ≥ 0.75) for most of the scapula rotations, independently from the movement and the inter-session offset. The only exception is the agreement for scapula protraction-retraction and for scapula medio-lateral rotation during abduction (inter-operator), which is acceptable only if the inter-session offset is removed. SDD(95) values ranged from 4.4° to 8.6° for the inter-operator and between 4.9° and 8.5° for the intra-operator agreement. In conclusion, ISEO presents a high intra- and inter-operator agreement, particularly with the scapula inter-session offset removed.

Centre of pressure displacements in trans-femoral amputees during gait.

The aim of this study was to describe and quantify centre of pressure (CoP) displacement during walking in 12 unilateral trans-femoral amputees who had worn a prosthesis for at least 10 years. All subjects wore the same type of prosthesis and seven healthy subjects acted as controls. The CoP was acquired by an F-scan system and the displacements along the longitudinal axis of the foot versus time were quantified. An asymmetry of both temporal and spatial parameters of CoP patterns occurred between the sound and the prosthetic foot. The double support time and the time during which the CoP remained in the heel and mid-foot region were longer for the prosthetic limb. Conversely, the stance phase was longer for the sound limb, as was the time spent by the CoP in the forefoot. There was a redistribution of the time during which the CoP remained within the different zones of the sound foot with respect to the normal feet of the control subjects. The asymmetry seen in trans-femoral amputee stance is due not only to an abnormal spatio-temporal distribution of the CoP under the prosthetic leg, but also to a modification of the spatio-temporal distribution of the CoP under the sound foot compared to the normal foot. We conclude that an adaptation occurs in the control of the stance phase on the sound side during amputee gait.