Raoul M. Bongers

Systematic review of the effectiveness of mirror therapy in upper extremity function

Purpose. This review gives an overview of the current state of research regarding the effectiveness of mirror therapy in upper extremity function. Method. A systematic literature search was performed to identify studies concerning mirror therapy in upper extremity. The included journal articles were reviewed according to a structured diagram and the methodological quality was assessed. Results. Fifteen studies were identified and reviewed. Five different patient categories were studied: two studies focussed on mirror therapy after an amputation of the upper limb, five studies focussed on mirror therapy after stroke, five studies focussed on mirror therapy with complex regional pain syndrome type 1 (CRPS1) patients, one study on mirror therapy with complex regional pain syndrome type 2 (CRPS2) and two studies focussed on mirror therapy after hand surgery other than amputation. Conclusions. Most of the evidence for mirror therapy is from studies with weak methodological quality. The present review showed a trend that mirror therapy is effective in upper limb treatment of stroke patients and patients with CRPS, whereas the effectiveness in other patient groups has yet to be determined.

Determining skill level in myoelectric prosthesis use with multiple outcome measures

To obtain more insight into how the skill level of an upper-limb myoelectric prosthesis user is composed, the current study aimed to (1) portray prosthetic handling at different levels of description, (2) relate results of the clinical level to kinematic measures, and (3) identify specific parameters in these measures that characterize the skill level of a prosthesis user. Six experienced transradial myoelectric prosthesis users performed a clinical test (Southampton Hand Assessment Procedure [SHAP]) and two grasping tasks. Kinematic measures were end point kinematics, joint angles, grasp force control, and gaze behavior. The results of the clinical and kinematic measures were in broad agreement with each other. Participants who scored higher on the SHAP showed overall better performance on the kinematic measures. They had smaller movement times, had better grip force control, and needed less visual attention on the hand. The results showed that time was a key parameter in prosthesis use and should be one of the main focus aspects of rehabilitation. The insights from this study are useful in rehabilitation practice because they allow therapists to specifically focus on certain parameters that may result in a higher level of skill for the prosthesis user.

Learning to Control Opening and Closing a Myoelectric Hand

OBJECTIVE To compare 3 different types of myoelectric signal training. DESIGN A cohort analytic study. SETTING University laboratory. PARTICIPANTS Able-bodied right-handed participants (N=34) randomly assigned to 1 of 3 groups. INTERVENTIONS Participants trained hand opening and closing on 3 consecutive days. One group trained with a virtual myoelectric hand presented on a computer screen, 1 group trained with an isolated prosthetic hand, and 1 group trained with a prosthetic simulator. One half of the participants trained with their dominant side, and the other half trained with their nondominant side. Before and after the training period, a test was administered to determine the improvement in skill. Participants were asked to open and close the hand on 3 different velocities at command. MAIN OUTCOME MEASURES Peak velocity, mean velocity, and number of peaks in the myoelectric signal of hand opening and closing. RESULTS No differences were found for the different types of training; all participants learned to control the myoelectric hand. However, differences in learning abilities were revealed. After learning, a subgroup of the participants could produce clearly distinct myoelectric signals, which resulted in the ability to open and close the hand at 3 different speeds, whereas others could not produce distinct myoelectric signals. CONCLUSIONS Acquired control of a myoelectric hand is irrespective of the type of training. Prosthetic users may differ in learning capacity; this should be taken into account when choosing the appropriate type of control for each patient.

The i-LIMB hand and the DMC plus hand compared: A case report

The i-LIMB hand is a novel upper limb myoelectric prosthetic hand with several joints in the fingers and thumb. This study aimed to determine whether this new device had more functionality than a more conventional myoelectric prosthetic hand with only a single joint between the thumb and two fingers. Therefore, a 45-year-old man with a wrist disarticulation used the i-LIMB hand and the widely used Dynamic Mode Control hand (DMC plus hand) in a test procedure that covered all functional levels of the International Classification of Function (ICF). Functional outcomes of the i-LIMB seemed to be lower than or equal to the DMC plus hand. The patients satisfaction tended to be in favor of the i-LIMB. Compared to the DMC plus hand, the i-LIMB was more reliable when holding objects but had a lack of power and was less robust. We concluded that the i-LIMB hand has limited additional functionality compared to the DMC plus hand.

Variations of tool and task characteristics reveal that tool-use postures are anticipated.

The authors examined anticipation in tool use, focusing on tool length and tool-use posture. Adults (9 women and 9 men in each experiment) held a rod (length 0.4-0.8 m), with the tip upward; walked toward a cube; chose a place to stop; and displaced the cube with the rods tip. In 2 experiments, rod length, mass, and mass distribution, and the size of the cube were manipulated. Chosen distance depended on rod length and cube size. Because effects of cube size on distance resulted only from postural changes related to required control, distance anticipated displacement posture. A postural synergy comprising legs and trunk provided a stable platform for the displacement. An arm synergy was less extended for small cubes, longer rods, and handleweighted rods. Selected distance anticipated those postures.

Movement characteristics of upper extremity prostheses during basic goal-directed tasks

BACKGROUND After an upper limb amputation a prosthesis is often used to restore the functionality. However, the frequency of prostheses use is generally low. Movement kinematics of prostheses use might suggest origins of this low use. The aim of this study was to reveal movement patterns of prostheses during basic goal-directed actions in upper limb prosthetic users and to compare this with existing knowledge of able-bodied performance during these actions. METHODS Movements from six users of upper extremity prostheses were analyzed, three participants with a hybrid upper arm prosthesis, and three participants with a myoelectric forearm prosthesis. Two grasping tasks and a reciprocal pointing task were investigated during a single lab session. Analyses were carried out on the kinematics of the tasks. FINDINGS When grasping, movements with both prostheses showed asymmetric velocity profiles of the reach and had a plateau in the aperture profiles. Reach and grasp were decoupled. Kinematics with the prostheses differed in that the use of upper arm prostheses required more time to execute the movements, while the movements were less smooth, more asymmetric, and showed more decoupling between reach and grasp. The pointing task showed for both prostheses less harmonic movements with higher task difficulty. INTERPRETATION Characterizing prosthetic movement patterns revealed specific features of prosthetic performance. Developments in technology and rehabilitation should focus on these issues to improve prosthetic use, in particular on improving motor characteristics and the control of the elbow, and learning to coordinate the reach and the grasp component in prehension.

The Role of Order of Practice in Learning to Handle an Upper-Limb Prosthesis

OBJECTIVE To determine which order of presentation of practice tasks had the highest effect on using an upper-limb prosthetic simulator. DESIGN A cohort analytic study. SETTING University laboratory. PARTICIPANTS Healthy, able-bodied participants (N=72) randomly assigned to 1 of 8 groups, each composed of 9 men and 9 women. INTERVENTIONS Participants (n=36) used a myoelectric simulator, and participants (n=36) used a body-powered simulator. On day 1, participants performed 3 tasks in the acquisition phase. On day 2, participants performed a retention test and a transfer test. For each simulator, there were 4 groups of participants: group 1 practiced random and was tested random, group 2 practiced random and was tested blocked, group 3 practiced blocked and was tested random, and group 4 practiced blocked and was tested blocked. MAIN OUTCOME MEASURES Initiation time, the time from the starting signal until the beginning of the movement, and movement time, the time from the beginning until the end of the movement. RESULTS Movement times got faster during acquisition (P<.001). The blocked group had faster movement times (P=.009), and learning in this group extended over the complete acquisition phase (P<.001). However, this advantage disappeared in the retention and transfer tests. Compared with a myoelectric simulator, movements with the body-powered simulator were faster in acquisition (P=.004) and transfer test (P=.034). CONCLUSIONS Performance in daily life with a prosthesis is indifferent to the structure in which the training is set up. However, practicing in a blocked fashion leads to faster performance; in novice trainees, it might be suggested to practice part of the training tasks in blocks.

Geometrics and dynamics of a rod determine how it is used for reaching

Abstract Displacing an object with a hand-held rod provided a simple paradigm for studying tool use. The authors asked how reaching was affected by manipulations of rod properties. Adults held a rod (length = .10 to 1.5 m), with its tip in the air; walked toward an object on a table; chose a place to stop; and displaced the object with the rods tip. In 3 experiments (Ns = 9, 22, and 17 participants), the authors manipulated rod length, mass, and mass distribution to determine whether and how geometric and dynamic properties affected the chosen distance and the posture. Both the chosen stopping distance and the postures were well accommodated to rod characteristics. Postural adaptations took place only in the arm, which was organized as a synergy. Predictably, rod length explained most of the variance, but small and reliable differences in both distance and posture depended on mass and mass distribution. The chosen distance anticipated not only rod length but also the upcoming posture needed to control the rod.

Efficiency of voluntary opening hand and hook prosthetic devices : 24 years of development?

Quantitative data on the mechanical performance of upper-limb prostheses are very important in prostheses development and selection. The primary goal of this study was to objectively evaluate the mechanical performance of adult-size voluntary opening (VO) prosthetic terminal devices and select the best tested device. A second goal was to see whether VO devices have improved in the last two decades. Nine devices (four hooks and five hands) were quantitatively tested (Hosmer model 5XA hook, Hosmer Sierra 2 Load VO hook, RSL Steeper Carbon Gripper, Otto Bock model 10A60 hook, Becker Imperial hand, Hosmer Sierra VO hand, Hosmer Soft VO hand, RSL Steeper VO hand, Otto Bock VO hand). We measured the pinch forces, activation forces, cable displacements, mass, and opening span and calculated the work and hysteresis. We compared the results with data from 1987. Hooks required lower activation forces and delivered higher pinch forces than hands. The activation forces of several devices were very high. The pinch forces of all tested hands were too low. The Hosmer model 5XA hook with three bands was the best tested hook. The Hosmer Sierra VO hand was the best tested hand. We found no improvements in VO devices compared with the data from 1987.

Changes in performance over time while learning to use a myoelectric prosthesis

BackgroundTraining increases the functional use of an upper limb prosthesis, but little is known about how people learn to use their prosthesis. The aim of this study was to describe the changes in performance with an upper limb myoelectric prosthesis during practice. The results provide a basis to develop an evidence-based training program.MethodsThirty-one able-bodied participants took part in an experiment as well as thirty-one age- and gender-matched controls. Participants in the experimental condition, randomly assigned to one of four groups, practiced with a myoelectric simulator for five sessions in a two-weeks period. Group 1 practiced direct grasping, Group 2 practiced indirect grasping, Group 3 practiced fixating, and Group 4 practiced a combination of all three tasks. The Southampton Hand Assessment Procedure (SHAP) was assessed in a pretest, posttest, and two retention tests. Participants in the control condition performed SHAP two times, two weeks apart with no practice in between. Compressible objects were used in the grasping tasks. Changes in end-point kinematics, joint angles, and grip force control, the latter measured by magnitude of object compression, were examined.ResultsThe experimental groups improved more on SHAP than the control group. Interestingly, the fixation group improved comparable to the other training groups on the SHAP. Improvement in global position of the prosthesis leveled off after three practice sessions, whereas learning to control grip force required more time. The indirect grasping group had the smallest object compression in the beginning and this did not change over time, whereas the direct grasping and the combination group had a decrease in compression over time. Moreover, the indirect grasping group had the smallest grasping time that did not vary over object rigidity, while for the other two groups the grasping time decreased with an increase in object rigidity.ConclusionsA training program should spend more time on learning fine control aspects of the prosthetic hand during rehabilitation. Moreover, training should start with the indirect grasping task that has the best performance, which is probably due to the higher amount of useful information available from the sound hand.