O034 Rockabye sailor: investigating the impact of simulated motion on sleep and cognitive performance

Background Many naval vessels are designed with sleeping berths orientated in a fore/aft direction. Reorientating the berths changes the rocking from side-to-side to head-to-foot. It is unknown what effect rocking orientation may have on sleep. Aim This study aimed to investigate the impact of a simulated fore/aft orientation (side-to-side motion) with a simulated athwartships berth orientation (head-to-foot motion), on sleep quality and quantity, and cognitive performance. Method 21 participants (13M/8F; 24.0±4.8 years; BMI 21.1±2.5) slept in berths on a motion platform replicating vessel motion. In a repeated measures design, each participant slept under three conditions in randomised order: 1) no motion, 2) fore/aft orientation (side-to-side motion), and 3) athwartships orientation (head-to-foot motion). Measurements of sleep (ambulatory polysomnography), sleepiness (Karolinska Sleepiness Scale: KSS), and vigilance (Psychomotor Vigilance Test: PVT) were analysed using Mixed Effects ANOVA. Results Participants’ total sleep time was shorter (p<0.001), sleep efficiency was reduced (p<0.001), they woke more frequently (p<0.001), and their sleep contained less REM (p<0.001) in the athwartships orientation (head-to-foot motion) compared to the no motion, and fore/aft orientation (side-to-side motion) conditions. Participants’ also reported significantly higher sleepiness on KSS (p=0.006), poorer subjective sleep quality (p<0.001), and displayed worse vigilant attention on PVT (p=0.03) following the athwartships orientation compared to the two other conditions. Discussion The simulated athwartships bunk orientation (head-to-foot motion) negatively impacted sleep and cognitive performance. These results may have implications for crew wellbeing. The data also gives unique theoretical insight into the effects of different types of rhythmic movement on sleep. Funding DSTG

Kinematic Synthesis of Gait Correction for a Rehabilitation Machine

This paper outlines the synthesis process for a redesign of the intelligently controlled assistive rehabilitation elliptical’s (ICARE) pedal system to enhance replication of gait-like movement patterns while training. The synthesized mechanism overcomes some limitations identified in certain ellipticals, specifically generation of taller, more rounded foot paths compared to over-ground gait. The proposed solution minimizes the position and angle difference curves between the ICARE foot motion and normal gait.

Evaluation of the effectiveness of inveterate Achilles tendon rupture V-Y plasty with immediate subsequent weight-bearing and rehabilitation. Case study

In our paper, we would like to present two cases of treatment of the Achilles tendon ruptures by means of surgical V-Y technique, and implementation of immediate rehabilitation and weight-bearing. V-Y plasty on ruptured tendons was performed. The continuity of the tendon was restored. The sheath of the tendon was stitched together. Dressing was put on; the foot was immobilized in a Walker-type shoe in pes equinus with heel pads and compression underwear. From the first hour after the procedure, the wound area was cooled with a Game Ready device. From the first day after the procedure, both patients were allowed to apply full weight to the limb in the shoe. The crutches were put away as soon as possible. Rehabilitation began right away on the next day; during its course, attempts were made to reduce the use of the shoe to a minimum and to achieve the full range of foot motion as soon as possible. In both patients, the full range of motion was reached approximately 2 weeks after the surgery. The video support for the article is available at: https://youtu.be/bi3xuwOT9vs

Contributions regarding 3D modelling of biomechanics of the foot

Within this paper, a detailed study is elaborated regarding the human foot during both orthostatic and gait, the main goal being to develop 3D models which are very useful in the foot motion and loading state research. In order to elaborate the accurate 3D modelling of the human foot assembly, a thorough biomechanical study is done. Such a study was required due to the fact of the high anatomical complexity of the motions within the foot, taking into consideration the 26 bones and 33 joints consisting it. The research aims the CAD modelling of the biomechanics of the healthy subjects alongside with predisposed pathological conditions. The resulting models will have important utility in both educational field and for further CAE approaches and studies.