Won-Kyung Song

Kinematic analysis of upper extremity movement during drinking in hemiplegic subjects

BACKGROUNDnIt is necessary to analyze the kinematic properties of a paralyzed extremity to quantitatively determine the degree of impairment of hemiplegic people during functional activities of daily living (ADL) such as a drinking task. This study aimed to identify the kinematic differences between 16 hemiplegic and 32 able-bodied participants in relation to the task phases when drinking with a cup and the kinematic strategy used during motion with respect to the gravity direction.nnnMETHODSnThe subjects performed a drinking task that was divided into five phases according to Murphys phase definition: reaching, forward transport, drinking, backward transport, and returning. We found that the groups differed in terms of the movement times and the joint angles and angular velocities of the shoulder, elbow, and wrist joints.nnnFINDINGSnCompared to the control group, the hemiplegic participants had a larger shoulder abduction angle of at most 17.1° during all the phases, a larger shoulder flexion angle of 7.6° during the reaching phase, and a smaller shoulder flexion angle of 6.4° during the backward transporting phase. Because of these shoulder joint patterns, a smaller elbow pronation peak angle of at most 13.1° and a larger wrist extension peak angle of 12.0° were found in the motions of the hemiplegic participants, as compensation to complete the drinking task. The movement in the gravity direction during the backward transporting phase resulted in a 15.9% larger peak angular velocity for elbow extension in the hemiplegic participants compared to that of the control group.nnnINTERPRETATIONnThese quantitative kinematic patterns help provide an understanding of the movements of an affected extremity and can be useful in designing rehabilitation robots to assist hemiplegic people with ADL.

Feedback training using a non-motorized device for long-term upper extremity impairment after stroke: a single group study.

[Purpose] To investigate the effect of feedback training using a non-motorized device on the upper extremity kinematic performance of chronic stroke survivors. [Subjects] This study had a single group design. Thirteen chronic stroke survivors (onset duration: 11.5u2005years, 62.6u2005years, mini-mental state examination score: 26.0) were enrolled. [Methods] The feedback training system consisted of a non-motorized device that offered weight support, and a projective display device and loud speakers that provided suitable visual and auditory feedback to the user. Subjects participated in the feedback training for 40u2005min per day, two times a week for 4 weeks. Upper extremity kinematic performance (i.e., movement time) in three directions was confirmed twice (at baseline and post-intervention). [Results] After 4 weeks of the intervention, a significant improvement in upper extremity kinematic performance was observed in the three directions. [Conclusion] The present study demonstrated the positive effects of feedback training using a non-motorized device on the upper extremity kinematic performance of chronic stroke survivors. Therefore, the findings of this study may provide beneficial information for future studies on feedback training using a non-motorized device for chronic stroke survivors.

Rhythmic auditory stimulation using a portable smart device: short-term effects on gait in chronic hemiplegic stroke patients.

[Purpose] The effects of various rhythmic auditory stimulation tempos on stroke gait pattern changes when training patients with a smartphone-based rhythmic auditory stimulation application were investigated. [Subjects and Methods] Fifteen patients with chronic stroke were included. Cadence during comfortable walking was measured (baseline). After the baseline findings were recorded, rhythmic auditory stimulation with five different tempos (i.e., −10%, −5%, 0%, +5%, and +10% change from baseline) was randomly applied. Finally, comfortable walking without rhythmic auditory stimulation was initiated to evaluate gait pattern changes. [Results] As the tempo increased, the spatiotemporal gait parameters of the stroke patients changed significantly. Gait speed, cadence, and gait cycle duration showed the greatest improvement in the +10% rhythmic auditory stimulation condition compared to baseline. After gait training with rhythmic auditory stimulation, gait speed, cadence, stride length, gait cycle duration, and step length of the affected and unaffected sides improved significantly compared to baseline. [Conclusion] Significant changes in the gait pattern of stroke patients were noted for various tempos after training with rhythmic auditory stimulation. These findings could be used to customize rehabilitative gait training for patients who experience stroke with hemiplegia.

Reaching contralateral target by chronic hemiparetic stroke survivors using active-assisted/active exercise with 2D/3D visual feedback

Chronic hemiparetic stroke survivors need 3D point-to-point movements every day at home. We compared device-assisted 3D reaching exercise performed by chronic stroke and evaluated the effect of active-assisted/active devices and 2D/3D visual feedback. We chose two arms to serve as upper extremity exercise devices, with active-assisted and active modes. 2D/3D visual feedback of the target position is projected on a large screen. The arm and display devices corresponded to the motor and cognitive functions of a subject, respectively. Thirty four chronic-stage stroke survivors were randomly placed in four groups. Four groups performed a set of reaching tasks over four weeks. Movement data such as movement velocity and curvilinearity ratio for the reaching tasks were compared, and based on this comparison, 3D visual feedback was found to be more effective than 2D visual feedback. When the target position changed, stroke survivors could effectively reach it with the help of the 3D visual feedback. The performance of the active-assisted exercise device was similar to that of a spring-loaded active exercise device. Active-assisted exercises can be applied to subjects who have difficulty in reaching movements, especially in the early sessions of reaching exercise.

Kinematic Comparison of Gait Rehabilitation with Exoskeleton and End-Effector Devices

Recently, various gait rehabilitation robots have been used as therapy in clinical fields for stroke, spinal cord injuries, and several neurological disorders. We investigated the kinematic differences with joint trajectories of two types of gait rehabilitation robots, i.e., exoskeleton and end-effector devices. Furthermore, we compared the end-effector device’s stair climbing and descending motions to actual motions. The exoskeleton device shows larger hip and knee angle than the end-effector device during gait. However, exoskeleton ankle joint was restricted in dorsiflexed position. The end-effector device’s stair climbing motion was similar to actual stair motion, although there was a delayed and lower maximum flexion. Compared with the actual motion, the stair descending motion had a lower maximum flexion angle for both hip and knee joints in the end-effector device. In addition, the end-effector device’s ankle trajectory was aligned with the dorsiflexion angle, while descending to the bottom stair.

Rhythmic auditory stimulation for robot-assisted gait rehabilitation: A preliminary study

In therapeutic rehabilitation devices, different types of feedback are provided to improve the outcome of the rehabilitation process. Lower limb robotic exoskeleton devices for overground gait rehabilitation have difficulties providing subjects certain types of feedback, such as visual feedback, because of the restriction of the visual display installation space and the mobility of the whole system. As a remedy, we propose the concept of providing auditory stimulation with force feedback via exoskeleton legs. As a preliminary study, we implemented an Android OS-based rhythmic auditory stimulation module in order to effectively connect exoskeleton robotic devices. Two 3D accelerometers were attached around the subjects ankles. By using this module, we performed a preliminary study on rhythmic auditory stimulation with able-bodied participants and one stroke participant. We observed changes in gait speed, cadence, and stride length in accordance with the rhythmic auditory stimulation. Based on these findings, a smartphone-based rhythmic auditory stimulator could add value to exoskeleton robotic devices.

Upper limb robotic rehabilitation for chronic stroke survivors: a single-group preliminary study

[Purpose] This study aimed to assess whether robotic rehabilitation can improve upper limb function, activities of daily living performance, and kinematic performance of chronic stroke survivors. [Subjects and Methods] Participants were 21 chronic stroke survivors (19 men; 60.8u2005years; Mini-Mental State Examination score: 28; onset duration: 10.2u2005years). Training exercises were performed with a Whole Arm Manipulator and a 120-inch projective display to provide visual and auditory feedback. Once the training began, red and grey balls appeared on the projective display, and participants performed reaching movements, in the assist-as-needed mode, toward 6 directional targets in a 3-dimensional space. All participants received training for 40 minutes per day, thrice per week, for 6 weeks. Main outcome measures were upper limb function (Fugl-Meyer Assessment, Action Research Arm Test, and Box and Blocks Test scores), activities of daily living performance (Modified Barthel Index), and kinematic performance (movement velocity) in 6 directions. [Results] After 6 weeks, significant improvement was observed in upper limb function, activities of daily living performance, and kinematic performance. [Conclusion] This study demonstrated the positive effects of robotic rehabilitation on upper limb function, activities of daily living performance, and kinematic performance in chronic stroke survivors.

Inference of Changes in Proprioception Using Kinematics in Robot-Assisted Reach Exercise for Chronic Stroke Survivors

In this study, we inferred the changes in proprioception through kinematic data analysis in repetitive robot-assisted reach exercise. It was assumed that proprioception could be inferred by observing the variability of point-to-point movements during exercise. Ten chronic stroke survivors performed the robot-assisted reach exercise for six weeks. The averaged distance between points passing through a virtual plane near a return target position and their centroid during the reach exercise was calculated as an index of the movement variability. The results showed that the variability was reduced by 15.7%. Using clinical assessment tools, functional arm movement improved by 6%. We can infer the changes in proprioception from the exercise based on the decrease of the variability.

T54. The difference of contralateral motor overflow according to spasticity among people with stroke

Introduction Contralateral motor overflow is known as overt involuntary movement from accompanied contralateral production of voluntary movement. The prevalence of motor overflow is high in patients with stroke. Many previous studies were reported, however there is lack of studies about the relationship between motor overflow and spasticity or musculoskeletal factor. The objective of the present study was to investigate the contralateral motor overflow in patients with stroke during finger force production tasks in terms of spasticity and musculoskeletal factor. Methods Forty-four patients with stroke, and 20 healthy control were participated in this study. Participants were seated and requested to put all fingers of both hands on force sensors (FUTEK) with various musculoskeletal factors (wrist posture: flexed, neutral, and extended posture) and speed (fast, slow). They produced maximum isometric pressing force with all fingers of right or left hand and the forces were recorded. We analyzed motor overflow magnitude, which is defined as the ratio of the non-task hand force to the corresponding task hand finger force. The spasticity was graded as modified Ashworth scale and we define that of healthy control as 0. Results Motor overflow was different according to spasticity and the difference was consistent regardless of wrist posture and speed (all, p p Conclusion We conclude that contralateral motor overflow during maximum force production tasks is dependent on the spasticity and speed of finger flexion regardless of physical wrist posture. Therefore, contralateral motor overflow could result from upper motor neuron lesion other than musculoskeletal facots.

Robot assisted reach training with an active assistant protocol for long-term upper extremity impairment after stroke: a randomized controlled trial

OBJECTIVEnTo assess whether robot-assisted reach training (RART) with an active assistant protocol can improve upper extremity function and kinematic performance in chronic stroke survivors.nnnDESIGNnThis study was conducted as a randomized controlled trial.nnnSETTINGnNational rehabilitation center.nnnPARTICIPANTSnChronic stroke survivors (N=38) were randomized into 2 groups: a robot-assisted reach training with assist-as-needed (RT-AAN) group and a robot-assisted reach training with guidance force (RT-G) group.nnnINTERVENTIONnThe RT-AAN group received robot-assisted reach training with an assist-as-needed mode for 40 minutes per day, 3 times per week over a 6-week period, and the RT-G group participated in the RART with a guidance mode for 40 minutes per day, 3 times per week over a 6-week period.nnnMAIN OUTCOME MEASURESnUpper extremity functions were measured with Fugl-Meyer Assessment (FMA), Action Research Arm Test (ARAT), and Box and Block Test. In addition, movement velocities were measured as an index for upper extremity kinematic performances in 6 directions.nnnRESULTSnBoth groups showed significant improvements in FMA, ARAT, and kinematics (movement velocity) in all directions (targets 1-6, P<.05). However, the RT-AAN group showed significantly more improvement than the RT-G group in FMA and ARAT (P<.05).nnnCONCLUSIONSnRART with an active assistant protocol showed improvements of upper extremity function and kinematic performance in chronic stroke survivors. In particular, assist-as-needed robot control was effective for upper extremity rehabilitation. Therefore robot-assisted training may be suggested as an effective intervention to improve upper extremity function in chronic stroke survivors.