Chau-Peng Leong

The traction angle and cervical intervertebral separation

Seventeen normal young adults were evaluated for cervical intervertebral separation under different traction angles through motorized intermittent traction in the supine position. In all cases, the anterior and posterior intervertebral spaces were increased by traction at neutral position and in 30°flexion, but not in 15° extension. The effects of separation were 1) neutral position: anterior intervertebral separation C4–5 (12%) > C3–4 (8%), posterior intervertebral separation C6–7 (37%) > C3–4 (22%) > C4–5 (19%); and 2) 30° flexion: anterior intervertebral separation C2–3 (21 %) > C4–5 (16%) > C5–6 (15%) > C3–4 (10%), posterior intervertebral separation C6–7 (20%) > C5–6 (19%) > C4–5 (17%). There was a significant decrease in intervertebral separation posteriorly in extension traction, especially at C6–7 (−50%), C5–6 (−37%), C4–5 (−26%), and C3–4 (−14%). The separation of facet joint surfaces was found after traction at 15° extension, but not in the neutral or flexion positions.

Improvement of gait by using orthotic insoles in patients with heel injury who received reconstructive flap operations

Tang SFT, Chen CPC, Hong WH, Chen HT, Chu NK, Leong CP: Improvement of gait by using orthotic insoles in patients with heel injury who received reconstructive flap operations. Am J Phys Med Rehabil 2003;82:350-356. Objective To investigate the effect of orthotic insoles in heel injury patients who received reconstructive flap operations. Design Motion analysis and force platform data were collected in able-bodied subjects and patients with heel injuries during walking without and with the use of the total contact insole. Gait kinetics were collected for the hip, knee, and ankle joints and then compared with Student’s t tests. Results Walking velocity and step length were decreased (P < 0.014 and P < 0.005) for patients not wearing the total contact insole. The affected limbs had longer double-support duration (14.8% of gait cycle, P < 0.037) and shorter single-support duration (34.5% of gait cycle, P < 0.045). Less hip power generation was noted for the affected limbs during both initial contact and preswing phases, 0.17 ± 0.10 N-m/kg-m and 0.45 ± 0.20 N-m/kg-m, as compared with that of the able-bodied subjects, 0.36 ± 0.08 N-m/kg-m and 0.89 ± 0.22 N-m/kg-m, respectively. Decreased ankle power generation was noted for the affected limbs (1.08 ± 0.38 N-m/kg-m) during preswing phase as compared with the able-bodied subjects (2.24 ± 0.33 N-m/kg-m). After fitting of the total contact insole, the affected limbs recovered to a gait pattern similar to that of the able-bodied subjects (P < 0.05). Conclusion Asymmetry of gait pattern after heel injury resulted in altered gait kinetics. Gait symmetry could be recovered in these patients as the total contact insole provides weight acceptance, shock absorption, and cushioning effect for the reconstructed heels.

Transmetatarsal amputation prosthesis with carbon-fiber plate: Enhanced gait function

Tang SFT, Chen CPC, Chen MJL, Chen WP, Leong CP, Chu NK: Transmetatarsal amputation prosthesis with carbon-fiber plate: Enhanced gait function. Am J Phys Med Rehabil 2004;83:124–130. ObjectiveTo determine whether the design of a transmetatarsal amputation prosthesis with a carbon-fiber plate would improve gait pattern in patients with transmetatarsal amputations. DesignIn the gait laboratory in a tertiary medical center, eight male patients with transmetatarsal amputations were recruited. Nine able-bodied male volunteers were recruited as the control group. A full-length standard shoe and a transmetatarsal amputation prosthesis with a carbon-fiber plate were the footwear used. Our transmetatarsal amputation prosthesis included a custom-molded insole, a mounted toe filler, and a thin, lightweight, carbon-fiber plate incorporated directly beneath the insole. ResultsAfter wearing the transmetatarsal amputation prosthesis with a carbon-fiber plate, the results of the kinetic and kinematic studies were summarized. ConclusionThe transmetatarsal amputation prosthesis with a carbon-fiber plate improved gait pattern significantly in patients with transmetatarsal amputations. Drastic shoe modifications are not necessary to have the prosthesis inserted. The carbon-fiber plate functions like the spring-steel shank within the sole of the shoe. The carbon-fiber plate, the toe filler, and the total-contact insole are all mounted as a whole to ensure better foot contact. Therefore, our transmetatarsal amputation prosthesis with a carbon-fiber plate can be a good alternative choice of footwear in patients with transmetatarsal amputations.