A Pilot Study Testing a Novel 3D Printed Amphibious Lower Limb Prosthesis in a Recreational Pool Setting.

INTRODUCTION: Adults with limb amputation and other physical disabilities are less likely to participate in physical activity than adults in the general population and have elevated risk of heart disease and stroke. Swimming is a physical activity often recommended for persons with limb amputation. However, a standard economical swim prosthesis that facilitates easy transition from land to water does not exist. OBJECTIVE: The objectives were (1) to measure ease of first-time use and likability of a novel U.S. Food and Drug Administration (FDA)-cleared 510(k) three-dimensional (3D) printed device, the "FIN," in a recreational pool; and (2) to determine differences in time to complete basic swim tasks using the novel 3D printed amphibious lower limb prosthesis or a standard Swim Ankle prosthesis. Our hypotheses were the following: (1) that the novel 3D printed amphibious lower limb prosthesis would be easy and likeable upon first use; and (2) that basic swim tasks would take comparable time to complete with either device. SETTING: Academic medical center and community pool in New York. PARTICIPANTS: Participants were (N = 10) English-speaking adults with a transtibial amputation who self-identified to swim comfortably in a recreational setting. INTERVENTIONS: Participants completed tasks typical of recreational swimming while wearing the novel 3D printed amphibious lower limb prosthesis or a Swim Ankle. MAIN OUTCOME MEASUREMENTS: Participants performed a series of recreational swim tasks at self-selected speeds: entering/exiting pool, walking, swimming, and treading water, and completed a survey to assess the primary outcomes: likability, ease of use, and adverse events (feasibility). RESULTS: Participants found the novel 3D printed amphibious lower limb prosthesis more likable compared to the Swim Ankle and easy to use. Time to exit the pool was significantly reduced with the novel 3D printed amphibious lower limb prosthesis, while time to complete a 25-m lap was comparable. Participants did not show significant changes in vital signs when using either prosthesis. CONCLUSIONS: The novel 3D printed amphibious lower limb prosthesis was likable and easy to use upon first use. This study supports conducting a larger clinical trial to determine if the data are broadly reproducible.

Treatment strategies for genu recurvatum in adult patients with hemiparesis: a case series.

OBJECTIVE: To report our clinical experience and propose a biomechanical factor-based treatment strategy for improvement of genu recurvatum (GR) to reduce the need for knee-ankle-foot orthosis (KAFO) or surgical treatment. DESIGN: Case series. SETTING: Outpatient clinic of a Department of Physical Medicine and Rehabilitation in an academic medical center. SUBJECTS AND INTERVENTIONS: Adult subjects (n = 22) with hemiparesis and GR who received botulinum injections alone or in combination with multiple types of orthotic interventions that included solid ankle-foot orthosis (AFO) ± heel lift, hinged AFO with an adjustable posterior stop ± heel lift, AFO with dual-channel ankle joint ± heel lift, or KAFO with offset knee joint. Biomechanical factors reviewed included muscle strength, modified Ashworth score for spasticity, presence of clonus, posterior capsule laxity, sensory deficits, and proprioception. OUTCOME MEASUREMENTS: Outcome factors were improvement or elimination of GR based on subjective assessment before and after the interventions by the same experienced clinician. RESULTS: More than one biomechanical factor contributed to GR in all patients. Botulinum toxin A injection was used in patients who had significant plantar flexor spasticity and/or clonus. Four types of orthotic interventions were used based on the biomechanical factor: solid AFO in patients with severe ankle dorsiflexion and plantar flexion weakness or clonus; hinged ankle joint with adjustable posterior stop in patients with less severe ankle dorsiflexion weakness in the absence of clonus; AFO with a dual-channel ankle joint for quadriceps weakness or severe proprioceptive deficits; and KAFO with offset knee joints in patients with Achilles tendon contracture or severe proprioceptive deficits. Adjunctive options included the addition of heel lifts and toeplate modifications. Combinatorial interventions of botulinum injection, modified AFOs, and heel lifts improved or eliminated GR and avoided the need for cumbersome orthotics or surgical interventions. CONCLUSIONS: GR in hemiparesis is multifactorial and can be successfully controlled by using a conservative biomechanical factor-based approach and combined medical and orthotic interventions. An algorithmic approach and a prospective study design is proposed to determine a combination of effective interventions to correct GR.