A novel device for improving marker placement accuracy.

BACKGROUND: Repeatability of marker placement has been acknowledged as a major factor affecting the reliability of multi-segment foot models. A novel device is proposed that is intended to reduce marker placement error and its effect on the reliability of inter-segmental foot kinematic data is investigated. METHOD: The novel device was tested on eight healthy subjects. Landmarks were identified and indicated on the subject's foot at the start of testing using pen, and these points were used to guide placement. Markers were twice attached by a podiatrist using a standard approach, and twice by a researcher who used the novel device. Replacement accuracy and the kinematic reliability of the foot model data for both techniques were analysed. RESULTS: The mean marker placement variability using the novel device placement device was 1.1mm (SD 0.28) compared to 1.4mm (SD 0.23) when using standard placement techniques. Results suggest that these reductions in placement error tended to improve the overall reliability of the multi-segment data from the foot model. DISCUSSION: The novel device is a simple and inexpensive tool for improving the placement consistency of skin-mounted markers.

Specificity of recumbent cycling as a training modality for the functional movements; sit-to-stand and step-up.

BACKGROUND: The principle of specificity in muscle training requires the training mode to reflect the desired outcome. The observed similarity of lower limb movements during recumbent cycling to the functional movements sit-to-stand and step-up presents the possibility of using recumbent cycling in a rehabilitation context. This may reduce the need to practice the actual task which in some, less able, patients may be labour intensive and patient fatiguing. To date no studies have compared recumbent cycling to these functional movements. This study therefore aimed to compare the lower limb kinematics and muscle activity between recumbent cycling and both sit-to-stand and step-up movements. METHODS: Electromyographic and kinematic signals from 12 young (mean age 42.1 years) healthy participants were collected during the performance of three activities: (1) cycling at 60 rpm, (2) sit-to-stand and (3) a single step-up. Only the extension phase of each movement was compared. FINDINGS: Although the results demonstrated differences in joint movement and muscle activation, e.g., greater gastrocnemius activity during recumbent cycling (P<0.00), knee range of motion and average root mean square activity for rectus femoris, biceps femoris and the sum of the average activity for five muscles recorded showed no difference (P>0.05) suggesting that there was sufficient agreement to support the use of recumbent cycling as a specific training modality for the sit-to-stand and step-up movements. This finding may have positive implications for the rehabilitation of a wide range of patients in the early stages of rehabilitation.