ABSTRACT
The functionalities of myoelectric hooks, such as whether they allow wrist movements, as well as the volume and design of the devices, may impact how fitted transradial amputees use their upper limbs. The aim of the current study was to compare two prosthetic myoelectric hooks in terms of compensatory shoulder movements, functionality and user satisfaction. This monocentric, randomized, controlled, cross-over trial evaluated eight transradial amputees fitted with two prosthetic myoelectric hooks, the Greifer and the Axon-Hook, during two consecutive periods. At the end of each period, shoulder abduction (mean and percentage of time with shoulder abduction > 60°) and manual dexterity were assessed using the Box and Blocks Test (BBT) on both sides, and satisfaction was assessed with the Evaluation of Satisfaction with Assistive Technology questionnaire. For each patient, data obtained with the BBT on the amputated side were compared with those obtained on the non-amputated side. Shoulder abduction was significantly higher with the Greifer (60.9°± 20.3°, p = 0.03) than with the Axon-Hook (39.8°± 16.9°) and also than with the NA side (37.6 ± 19.4°, p = 0.02). Shoulder abduction on the NA side (37.6 ± 19.4°) was close to that of the Axon-Hook (39.8°± 16.9°). The percentage of time spent with shoulder abduction > 60° during the BBT was higher with the Greifer than with the Axon-Hook or with the NA side (53.3 ± 34.4%, 17.6 ± 27.0% and 18.4 ± 34.9%, respectively), but the differences were not significant (p = 0.15). A significant strong negative correlation was found between shoulder abduction and wrist position with the Axon-Hook (r = -0.86; p < 0.01), but not with the Greifer. Manual dexterity and satisfaction did not differ significantly between the two devices. These results revealed compensatory movements, such as shoulder abduction in transradial amputees equipped with hooks, themselves influenced by the prosthetic device settings.
Subject(s)
Amputees , Artificial Limbs , Humans , Shoulder/surgery , Wrist , Upper Extremity , Prosthesis DesignABSTRACT
OBJECTIVES: To analyze the spatiotemporal parameters in the terminal swing phase of the prosthetic limb in unilateral transfemoral amputees (TFAs) compared with a group of asymptomatic subjects, and to identify a latency period (LP) in the TFA between the full extension of the prosthetic knee and the initial ground contact of the ipsilateral foot. To study the correlation between the LP and the duration of the swing phase. To evaluate the influence of the type of knee, the time since amputation, and the amputation level on the latency period. DESIGN: Three-dimensional gait analysis with an optoelectronic device. SETTING: Gait analysis laboratory of a re-education and functional rehabilitation service. PARTICIPANTS: TFA (n=29) and able-bodied (n=15) subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Spatiotemporal and kinematics gait parameters. RESULTS: The swing phase and the LP of the prosthetic limb, associated with a consequently longer single-limb stance phase in the intact limb, were significantly longer than those measured in the intact limbs of these subjects, as well as those measured on both lower limbs of the able-bodied subjects (P<.05). There is a positive correlation (P<.05; r(2)=.58 between the LP and the swing phase on the TFA's prosthetic side. The LP measured in the prosthetic limb of TFA with a swing-phase control prosthetic knee is significantly greater than in those using the microprocessor-controlled prosthetic knee (P<.05). CONCLUSIONS: Of negligible duration in able-bodied subjects and in the intact limb of TFA, the LP is significantly greater in the prosthetic limb. It can explain the lengthened swing phase on the prosthetic side of those subjects. The use of a microprocessor-controlled prosthetic knee allows the LP to be reduced. This LP appears to be necessary to insure the stability of the prosthetic knee. We suggest calling this time "confidence time."
