Objectives: The objective of the study was to evaluate the safety and tolerance of use of the ReWalk ™ exoskeleton ambulation system in people with spinal cord injury. Measures of functional ambulation were also assessed and correlated to neurological spinal cord level, age, and duration since injury. Study design: Case series observational study. Setting: A national spinal cord injury centre. Methods: Six volunteer participants were recruited from the follow-up outpatient clinic. Safety was assessed with regard to falls, status of the skin, status of the spine and joints, blood pressure, pulse, and electrocardiography (ECG). Pain and fatigue were graded by the participants using a visual analogue scale pre-and post-training. Participants completed a 10-statement questionnaire regarding safety, comfort, and secondary medical effects. After being able to walk 100 m, timed up and go, distance walked in 6 minutes and 10-m timed walk were measured. Results: There were no adverse safety events. Use of the system was generally well tolerated, with no increase in pain and a moderate level of fatigue after use. Individuals with lower level of spinal cord injury performed walking more efficiently. Conclusion: Volunteer participants were able to ambulate with the ReWalk ™ for a distance of 100 m, with no adverse effects during the course of an average of 13-14 training sessions. The participants were generally positive regarding the use of the system.

The serial reaction time (SRT) task has generated a very large amount of research. Nevertheless the debate continues as to the exact cognitive processes underlying implicit sequence learning. Thus, the first goal of this study is to elucidate the underlying cognitive processes enabling sequence acquisition. We therefore compared reaction time (RT) in sequence learning in a standard manual activated (MA) to that in an ocular activated (OA) version of the task, within a single experimental setting. The second goal is to use eye movement measures to compare anticipation, as an additional indication of sequence learning, between the two versions of the SRT. Performance of the group given the MA version of the task (n = 29) was compared with that of the group given the OA version (n = 30). The results showed that although overall, RT was faster for the OA group, the rate of sequence learning was similar to that of the MA group performing the standard version of the SRT. Because the stimulus-response association is automatic and exists prior to training in the OA task, the decreased reaction time in this version of the task reflects a purer measure of the sequence learning that occurs in the SRT task. The results of this study show that eye tracking anticipation can be measured directly and can serve as a direct measure of sequence learning. Finally, using the OA version of the SRT to study sequence learning presents a significant methodological contribution by making sequence learning studies possible among populations that struggle to perform manual responses.

Obtaining an objective assessment of pain is an important challenge for clinicians. The purpose of this study is to examine the connections between subjective reports of pain and measureable biosignals of human speech prosody, as a step towards coping with this challenge. Patients reporting pain were voice-recorded to attain reports on different levels of pain. Recording was done in the patients' natural environment at the medical center. Features were extracted from the voice-recordings, including features that were exclusively developed for this study. A machine-learning based classification process was performed in order to distinguish between samples with "no significant pain" and with "significant pain" reported. This classification process distinguished well between the two categories. Moreover, features developed during this study improved classification results in comparison to classification based solely on knownfeatures. Results indicate that there is evidence of a connection between measureable biosignal parameters of speech and the simultaneous self-reported pain level. This finding might be useful for developing future methods to more objective assessment of pain.

Human locomotion is defined by bilateral coordination of gait (BCG) and shared features with the fore-hindlimb coordination of quadrupeds. The objective of the present study is to explore the influence of arm swinging (AS) on BCG. Sixteen young, healthy individuals (eight women; eight right motor-dominant, eight left-motor dominant) participated. Participants performed 10 walking trials (2 min). In each of the trials AS was unilaterally manipulated (e.g., arm restriction, weight on the wrist), bilaterally manipulated, or not manipulated. The order of trials was random. Walking trials were performed on a treadmill. Gait kinematics were recorded by a motion capture system. Using feedback-controlled belt speed allowed the participants to walk at a self-determined gait speed. Effects of the manipulations were assessed by AS amplitudes and the phase coordination index (PCI), which quantifies the left-right anti-phased stepping pattern. Most of the AS manipulations caused an increase in PCI values (i.e., reduced lower limb coordination). Unilateral AS manipulation had a reciprocal effect on the AS amplitude of the other arm such that, for example, over-swinging of the right arm led to a decrease in the AS amplitude of the left arm. Side of motor dominance was not found to have a significant impact on PCI and AS amplitude. The present findings suggest that lower limb BCG is markedly influenced by the rhythmic AS during walking. It may thus be important for gait rehabilitation programs targeting BCG to take AS into account. Control mechanisms for four-limb coordination in human locomotion are not fully known. To study the influence of arm swinging (AS) on bilateral coordination of the lower limbs during walking, we introduced a split-AS paradigm in young, healthy adults. AS manipulations caused deterioration in the anti-phased stepping pattern and impacted the AS amplitudes for the contralateral arm, suggesting that lower limb coordination is markedly influenced by the rhythmic AS during walking.