The impact of shoes versus ankle-restricted orthoses on sit-to-stand kinematics and centre of mass trajectories in adults with myelomeningocele

Background: Individuals with myelomeningocele (MMC) present with neurological and orthopaedic deficiencies, requiring orthoses during walking. Orthoses for counteracting dorsiflexion may restrict activities such as rising from a chair.

Research question: How are sit-to-stand (STS) movements performed with ankle joint-restricted ankle-foot orthoses (AFO) and knee-ankle-foot orthoses with a free-articulated knee joint (KAFO-F)?

Methods: Twenty-eight adults with MMC, mean age 25.5 years (standard deviation: 3.5 years), were divided into an AnkleFree group (no orthosis or a foot orthosis) and an AnkleRestrict group (AFOs or KAFO-Fs). Study participants performed the five times STS test (5STS) while their movements were simultaneously captured with a three-dimensional motion system. Centre of mass (CoM) trajectories and joint kinematics were analysed using statistical parametric mapping.

Results: The AnkleRestrict group performed the STS slower than the AnkleFree group, median 8.8 s (min, max: 6.9, 14.61 s) vs 15.0 s (min, max: 7.5, 32.2 s) (p = 0.002), displayed reduced ankle dorsiflexion (mean difference: 6°, p = 0.044) (74-81 % of the STS cycle), reduced knee extension (mean difference: 14°, p = 0.002) (17-41 % of the STS cycle), larger anterior pelvic tilt angle (average difference: 11°, p = 0.024) (12-24 % of the STS cycle), and larger trunk flexion angle (on average 4°, p = 0.029) (6-15 % of the STS cycle).

Significance: The differences between the AnkleFree and AnkleRestrict groups in performing the STS seem consistent with the participants functional ambulation: community ambulation in the AnkleFree group, and household and nonfunctional ambulation with less hip muscle strength in the majority of the AnkleRestrict group. No differences in the 5STS CoM trajectories or the kinematics were found with respect to the AFO and KAFO-Fs groups. Because orthoses are constructed to enable walking, the environment needs to be adjusted for activities in daily living such as the STS movement.