Seated postural abilities are critical to functional independence and participation in children with cerebral palsy, Gross Motor Functional Classification System (GMFCS) levels III-IV. In this proof-of-concept study, we investigated the feasibility of a motor learning-based seated postural training with a robotic Trunk-Support-Trainer (TruST) in a longitudinal single-subject-design (13y, GMFCS IV), and its potential effectiveness in a group of 3 children (6-14y, GMFCS III-IV). TruST is a motorized-cable driven belt placed on the child's trunk to exert active-assistive forces when the trunk moves beyond stability limits. TruST-intervention addresses postural-task progression by tailoring the assistive-force fields to the child's sitting balance to train trunk control during independent short-sitting posture. TruST-intervention consisted of 2 training blocks of six 2hour-sessions per block (3 sessions per week). Pelvic strapping was required in the 1 ^st block to prevent falls. As primary outcomes, we used the modified functional reach test, gross motor function measure-item set (GMFM-IS), Box & Blocks, and postural kinematics. After TruST-intervention children did not require pelvic strapping to prevent a fall, improved trunk stability during reaching (baseline = 5.49cm, 1week post-training = 16.38cm, 3mos follow-up = 14.63cm, ${P} <; 0.001$ ) and increased their sitting workspace (baseline = 127.55cm ² , 1week post-training, = 409.92cm ² , 3mos follow-up = 270.03cm ² , ${P} <; 0.001$ ). Three children also improved in the GMFM-IS. In summary, our novel robotic TruST-intervention is feasible and can effectively maximize functional independent sitting in children with CP GMFCS III-IV.

Functional rehabilitation of patients with spinal cord injury remains a current challenge. Training these patients to successfully stand is the first step towards restoring advanced skills such as walking. To address this need, we have developed a novel robotic stand trainer that can apply controlled forces on the trunk and the pelvis of a user, while controlling the knee angle. The stand trainer utilizes cables to apply assistive, resistive, or perturbation forces at the trunk, pelvis, and the knees, simultaneously. We have conducted a human study to validate the system. In this study, we applied multi-direction perturbation forces either at the pelvis or the trunk while assist-as-needed forces were applied to the other segment to keep balance. This study characterizes the human kinematics and measures of balance under the perturbations and assistive forces on the human body. Results shows that the level of force-field assistance (trunk or pelvis) directly affects the motion of the trunk, pelvis, and center of pressure. This provides a quantitative framework to restore balance in patients while providing assistance only when needed. This stand trainer can potentially free up therapists to attend to higher level rehabilitation goals and objectively assist patients to engage in interventions that challenge both their musculoskeletal and sensorimotor impairments.

Summary: People with severe neuromuscular trunk impairment cannot maintain or control upright posture of the upper body in sitting while reaching. Passive orthoses are clinically available to provide support and promote the use of upper extremities in this population. However, these orthoses only position the torso passively without any degree of trunk movement.We introduce for the first time a novel active-assistive torso brace called Wheelchair Robot for Active Postural Support (WRAPS). It consists of two rings over the hips and chest connected by a 2RPS-2UPS parallel robotic device. WRAPS can modulate the displacement of the upper ring and/or the forces applied on the torso through the ring in four degrees-of-freedom (DOF), including rotations and translation in the sagittal and frontal planes.In the present study, we evaluate the design of WRAPS and its functions. Moreover, we discuss the potential effectiveness of WRAPS as a therapeutic robotic tool in people with severe trunk control deficits. The performance of WRAPS was evaluated in seated healthy subjects. Kinematics and surface electromyography (sEMG) were collected when the participants performed selective trunk movements. First, the torso range of motion (tROM) was calculated with WRAPS in transparent mode—zero-force control mode—which was compared with free-guided tROM (no WRAPS) with motion capture system. Second, a position control mode was configured to mobilize the torso along the trajectories obtained with the transparent mode.Our results show that the design of WRAPS suited well the subject’s anthropometrics while supporting the weight of the torso. Importantly, WRAPS can be programmed to replicate the subject’s tROM, without the full activation of torso muscles. This can be critical in individuals with no trunk control. Altogether, these preliminary results indicate the potential applicability of WRAPS to promote active-assistive trunk mobility in people who cannot sit independently because of trunk dysfunction.

Aim: Children with moderate-severe cerebral palsy (CP) show postural control deficits that affect their daily activities, like reaching. The Seated Postural and Reaching Control test (SP&R-co) was developed to address the need for clinical measures that objectively identify dimensions of postural imbalance and corresponding reaching limitations in children with CP. Methods: SP&R-co documentation was designed for test validity and rater training. Rater and internal consistency were examined using Cronbach’s α. Reference SP&R-co score sheets of children and rater’s scores were used for absolute item-by-item, average inter-rater, and intra-rater reliability. Motor classification systems and performance tests were used for construct and concurrent validity. Results: The SP&R-co scoring showed acceptable-good consistency (α = 0.76–0.84). Interrelatedness of SP&R-co items was good-excellent (α = 0.82–0.97). The raters demonstrated fair, good, and excellent item-by-item reliability (ICC = 0.41–0.92). Inter-rater and intra-rater reliability of SP&R-co dimensions were good-excellent (ICC = 0.68–0.86 and ICC = 0.64–0.95, respectively). Construct and concurrent validity showed moderate-excellent correlations (r = 0.49–0.88). Conclusions: Results provide evidence that the SP&R-co is a reliable and valid test for therapists to objectively examine and quantify seated postural and reaching control in children with CP.

Purpose: We describe the development of an observational video coding tool, the Rehabilitation Observation Measure of Engagement (ROME), to quantify engagement in rehabilitative settings at the person (internal state of an individual) and between-system (interaction between individuals) level. Methods: Forty-nine children with unilateral spastic cerebral palsy (29 males; Age: M = 9.28 yrs, SD = 3.08 yrs) and their interventionists were videotaped during different activities. Construct validity was examined by correlating the ROME with the Engagement vs. Disaffection with Learning Survey and the Pediatric Rehabilitation Intervention Measure of Engagement – Observation questionnaire. Inter- and intra-rater reliability were examined using two independent raters. The ROME’s responsiveness to change was examined by comparing scores across activities. Results: For construct validity, results showed a positive correlation for person-level engagement (r = 0.444, p = 0.003). No relationship was found between-system-level engagement. High intrarater (91.8%) and interrater (96.1%) reliability was found. The ROME’s responsiveness to change was supported by children exhibiting lower engagement scores during repetitive shaping activities. Conclusion: These findings provide evidence that the ROME is a reliable tool to objectively examine the construct of engagement within rehabilitation and is valid for quantifying person-level engagement. It provides information that cannot be extracted from questionnaires and can help guide intervention decisions.

In people with severe neuromotor deficits of trunk and lower extremities, regaining balance in standing is often performed in rehabilitation with manual assistance, rigid body supports or by the use of handrails. To investigate and further expand postural control training in standing, we developed a Robotic Upright Stand Trainer (RobUST). In this study, we used RobUST to deliver trunk perturbations while simultaneously providing postural assistive forces on the pelvis in 10 able-bodied adults. Posture control responses with 'pelvic support' was then compared to 'no support' and 'hand supported' standing, with and without assistance from RobUST. We characterize postural imbalance with kinematic displacements and center of pressure (COP) outcomes, such as amplitude and root mean square of the excursions of COP. Surface electromyography (sEMG) was also applied to investigate muscle control. We additionally investigated ground reaction and handrail forces during standing to analyze how postural strategies and muscle mechanisms with 'pelvic support' via RobUST would differ from standing with 'no support' and with the 'handrail support'. Our results show that during perturbations, pelvic assistive support decreased kinematic and COP excursions compared to standing with no support. The pelvic assistance from RobUST showed similar level of COP changes as the use of handrail support but without reducing muscle activity or ground reaction forces. As expected, the maximum level of postural stability was observed when participants used the handrail and received pelvic assistive forces. In conclusion, RobUST demonstrates potential as a training device since it enhances postural balance without significantly removing muscular control mechanisms that are of interest in re-training postural control strategies in standing.