A robot-assisted sensorimotor training program can improve proprioception and motor function in stroke survivors

Proprioceptive deficits are common among stroke survivors and are associated with slower motor recovery, poorer upper limb motor function, and decreased self-care ability. Somatosensory feedback augmenting proprioception should enhance motor control after stroke, but available evidence is inconclusive. This study evaluated the effects of a robot-aided, somatosensory-focused training on proprioceptive acuity and motor performance in individuals with sub-acute and chronic stroke. Twelve stroke survivors completed two training sessions on two consecutive days. During training, participants used a haptic robotic wrist exoskeleton and made continuous, goal-directed wrist ab/adduction movements to a visual target while receiving vibro-tactile feedback. Proprioceptive acuity and active movement errors were assessed before, immediately after, and two days after intervention. Results showed significantly improved proprioceptive acuity at posttest and retention. Motor accuracy measures showed improvements, however these were not statistically significant. This study demonstrates the feasibility of robot-aided somatosensory rehabilitation training in stroke survivors.

Laryngeal vibration as a non-invasive neuromodulation therapy for spasmodic dysphonia

Spasmodic dysphonia (SD) is an incurable focal dystonia of the larynx that impairs speech and communication. Vibro-tactile stimulation (VTS) alters afferent proprioceptive input to sensorimotor cortex that controls speech. This proof-of-concept study examined the effect of laryngeal VTS on speech quality and cortical activity in 13 SD participants who vocalized the vowel /a/ while receiving VTS for 29 minutes. In response to VTS, 9 participants (69%) exhibited a reduction of voice breaks and/or a meaningful increase in smoothed cepstral peak prominence, an acoustic measure of voice/speech quality. Symptom improvements persisted for 20 minutes past VTS. Application of VTS induced a significant suppression of theta band power over the left somatosensory-motor cortex and a significant rise of gamma rhythm over right somatosensory-motor cortex. Such suppression of theta oscillations is observed in patients with cervical dystonia who apply effective sensory tricks, suggesting that VTS in SD may activate a similar neurophysiological mechanism. Results of this feasibility study indicate that laryngeal VTS modulates neuronal synchronization over sensorimotor cortex, which can induce short-term improvements in voice quality. The effects of long-term VTS and its optimal dosage for treating voice symptoms in SD are still unknown and require further systematic study.

Constituents of effective support for homecare workers providing care to people with dementia at end of life

OBJECTIVE

The aim of this study was to enhance understanding about homecare workers providing care to people with dementia at end of life by exploring homecare workers' perceptions of challenges and the support they needed and sometimes received.

METHODS

Qualitative semi-structured interviews were conducted with 29 homecare workers and 13 homecare managers in England. Framework analysis was used to analyse the data.

FINDINGS

Four overarching challenges were identified: working with clients with dementia, including clients' sometimes unpredictable responses, communication difficulties, and mood changes; caring for the dying; conflict with family members; and working alone, which often left homecare workers at risk of exhaustion, fatigue, and a sense of isolation. When their work entailed high levels of emotion, such as a client's death or getting embroiled in a client's family conflict, they felt emotionally drained, under-prepared, and overwhelmed. Supportive elements include receiving encouragement and learning from experienced peers and their feelings being acknowledged by managers at their employing homecare agency. Some workers were offered time off or encouraged to attend the client's funeral as a means of supporting the process of bereavement.

CONCLUSIONS

Peer and manager support are essential and effective in coping with work pressures. There is a need to develop models of effective support to alleviate staff's practical, emotional, and interpersonal pressures. However, due to the isolating nature of homecare work, managers may not recognise early signs of their staff finding stress unmanageable and miss the opportunity to mitigate these negative effects.

Development of Proprioceptive Acuity in Typically Developing Children: Normative Data on Forearm Position Sense

This study mapped the development of proprioception in healthy, typically developing children by objectively measuring forearm position sense acuity. We assessed position sense acuity in a cross-sectional sample of 308 children (5–17 years old; M/F = 127/181) and a reference group of 26 healthy adults (18–25 years old; M/F = 12/14) using a body-scalable bimanual manipulandum that allowed forearm flexion/extension in the horizontal plane. The non-dominant forearm was passively displaced to one of three target positions. Then participants actively matched the target limb position with their dominant forearm. Each of three positions was matched five times. Position error (PE), calculated as the mean difference between the angular positions of the matching and reference arms, measured position sense bias or systematic error. The respective standard deviation of the differences between the match and reference arm angular positions (SDP_diff) indicated position sense precision or random error. The main results are as follows: First, systematic error, measured by PE, did not change significantly from early childhood to late adolescence (Median PE at 90° target: −2.85° in early childhood; −2.28° in adolescence; and 1.30° in adults). Second, response variability as measured by SDP_diff significantly decreased with age (Median SDP_diff at 90° target: 9.66° in early childhood; 5.30° in late adolescence; and 3.97° in adults). The data of this large cross-sectional sample of children document that proprioceptive development in typically developing children is characterized as an age-related improvement in precision, not as a development or change in bias. In other words, it is the reliability of the perceptual response that improves between early childhood and adulthood. This study provides normative data against which position sense acuity in pediatric patient populations can be compared. The underlying neurophysiological processes that could explain the observed proprioceptive development include changes in the tuning of muscle spindles at the spinal level, the maturation of supraspinal somatosensory pathways and the development of interhemispheric callosal connections responsible for the transfer of somatosensory information.

The effectiveness of proprioceptive training for improving motor function: a systematic review

OBJECTIVE

Numerous reports advocate that training of the proprioceptive sense is a viable behavioral therapy for improving impaired motor function. However, there is little agreement of what constitutes proprioceptive training and how effective it is. We therefore conducted a comprehensive, systematic review of the available literature in order to provide clarity to the notion of training the proprioceptive system.

METHODS

Four major scientific databases were searched. The following criteria were subsequently applied: (1) A quantified pre- and post-treatment measure of proprioceptive function. (2) An intervention or training program believed to influence or enhance proprioceptive function. (3) Contained at least one form of treatment or outcome measure that is indicative of somatosensory function. From a total of 1284 articles, 51 studies fulfilled all criteria and were selected for further review.

RESULTS

Overall, proprioceptive training resulted in an average improvement of 52% across all outcome measures. Applying muscle vibration above 30 Hz for longer durations (i.e., min vs. s) induced outcome improvements of up to 60%. Joint position and target reaching training consistently enhanced joint position sense (up to 109%) showing an average improvement of 48%. Cortical stroke was the most studied disease entity but no clear evidence indicated that proprioceptive training is differentially beneficial across the reported diseases.

CONCLUSIONS

There is converging evidence that proprioceptive training can yield meaningful improvements in somatosensory and sensorimotor function. However, there is a clear need for further work. Those forms of training utilizing both passive and active movements with and without visual feedback tended to be most beneficial. There is also initial evidence suggesting that proprioceptive training induces cortical reorganization, reinforcing the notion that proprioceptive training is a viable method for improving sensorimotor function.