Standing stability of the medial linkage KAFOs using functional electrical stimulation in complete paraplegia

A medial linkage device called Primewalk was developed by Saitoh et al. to connect two KneeAnkle-Foot Orthoses (KAFOs). This device enabled to improve for paraplegic gait not only using orthosis but addition to functional electrical stimulation (FES). The purpose is to investigate the postural stability with the Primewalk device liked KAFOs in a paraplegic patient using FES. The complete T8 paraplegic patient, who has trained the gait for 7years using FES with medial linkage KAFOs participated in this study. The center of pressure (CoP) was measured during stance by force platform and calculated mean amplitude of sway and sway path. These parameter were evaluated under three conditions:(1) quiet standing, (2) pegs moving, and (3) plates staking. The results revealed that there were no significant differences between the Walkabout device and Primewalk one. The results suggested that the Primewalk provides the postural control as stable as the Walkabout during stance without upper limb support. Introduction/Background The application of the functional electrical stimulation (FES) to paralyzed muscles combined with medial linkage Knee-Ankle-Foot Orthoses (KAFOs) is useful for reconstruction of standing and ambulation for paraplegics. It enables easily don/doff, combining with the use of wheel chair. [1-2] Moreover, paraplegics can stand up from the wheel chair using FES with unlocked knee KAFOs. [3] The Walkabout device is a well-reported medial linked device that attaches to both KAFOs to form a medial linkage joint. [4] However, with the Walkabout device, the walking speed is considerably slower with shorter step length, because of height discrepancy between the axes of device and hip joint. [5] Saitoh et al. [2] invented the new device called Primewalk (Fig. 1-a, b) to solve this problem. The Primewalk device has a virtual axis near the hip joint height based on a sliding arc guide which attaches both KAFOs medially same as the Walkabout device. The Primewalk device improved walking speed and step length as compared with Walkabout device. Middleton et al. [1] investigated the postural control during stance in paraplegia using the Walkabout device medially linked KAFOs. In that report, quiet standing and two tasks, moving straws and plates were measured by force platform and the mean amplitude of sway and sway path of center of pressure (CoP) was evaluated. The purpose of this study was to compare quiet standing and task during standing without upper limb support between the Walkabout device and the Primewalk device in a complete T8 paraplegic patient using FES with unlocked knee KAFOs.