Kuan-Wen Wu1, Jia-Da Li2, Hsing-Po Huang2, Yen-Hung Liu2, Ting-Ming Wang3, Ya-Ting Ho4, Tung-Wu Lu5. 1. Department of Biomedical Engineering, National Taiwan University, Taiwan, R.O.C.; Department of Orthopaedic Surgery, School of Medicine, National Taiwan University, Taiwan, R.O.C.; Department of Orthopaedic Surgery, National Taiwan University Hospital, Taiwan, R.O.C. 2. Department of Biomedical Engineering, National Taiwan University, Taiwan, R.O.C. 3. Department of Orthopaedic Surgery, School of Medicine, National Taiwan University, Taiwan, R.O.C.; Department of Orthopaedic Surgery, National Taiwan University Hospital, Taiwan, R.O.C. 4. Department of Biomedical Engineering, National Taiwan University, Taiwan, R.O.C.; Department of Orthopaedic Surgery, National Taiwan University Hospital, Taiwan, R.O.C. 5. Department of Biomedical Engineering, National Taiwan University, Taiwan, R.O.C.; Department of Orthopaedic Surgery, School of Medicine, National Taiwan University, Taiwan, R.O.C.. Electronic address: twlu@ntu.edu.tw.
Abstract
INTRODUCTION: Adolescent idiopathic scoliosis (AIS) is the most common three-dimensional spinal deformity pathology during adolescence, often accompanied with sensory integration and proprioception problems, which may lead to abnormal postural control and altered end-point control during functional activities. This paper identifies the effects of AIS on the end-point control and on angular kinematics of the trunk and pelvis-leg apparatus during obstacle-crossing for both the concave- and convex-side limb leading. MATERIALS AND METHODS: Sixteen adolescents with severe Lenke 1 AIS (age: 14.9 ± 1.7 years, height: 154.7 ± 5.0 cm) and sixteen healthy controls (age: 14.8 ± 2.7 years, height: 154.9 ± 5.6 cm) each walked and crossed obstacles of 3 heights with either the concave- (AIS-A) or convex-side (AIS-V) limb leading. Angular motions of the trunk, pelvis and lower limbs, and toe-obstacle clearances were measured. Two-way analyses of variance were used to study between-subject (group) and within-subject (limb and height) effects on the variables. Whenever a height effect was found, a polynomial test was used to determine the linear trend. α = 0.05 was set for all tests. RESULTS: Patients with AIS significantly reduced pelvic downward list but increased dorsiflexion in both stance and swing ankles at leading limb crossing when compared to controls (p < 0.05). During AIS-A, additional kinematic modifications were observed, i.e., increased stance hip adduction (4.2 ± 0.8°, p = 0.005) and increased swing knee flexion (12.6 ± 1.4°, p = 0.106), with significantly decreased leading toe-clearance (AIS-A: 121.4 ± 6.7 mm, controls: 140.1 ± 5.6 mm, p = 0.031). CONCLUSIONS: Patients with AIS adopted an altered kinematic strategy for successful obstacle-crossing. With the concave-side limb leading, more joint kinematic modifications with reduced toe-clearance were found when compared to those during the convex-side limb leading, suggesting an increased risk of tripping. Further studies on the kinematic strategies adopted by different types of AIS will be needed for a more complete picture of the functional adaptations in such patient group.
INTRODUCTION:Adolescent idiopathic scoliosis (AIS) is the most common three-dimensional spinal deformity pathology during adolescence, often accompanied with sensory integration and proprioception problems, which may lead to abnormal postural control and altered end-point control during functional activities. This paper identifies the effects of AIS on the end-point control and on angular kinematics of the trunk and pelvis-leg apparatus during obstacle-crossing for both the concave- and convex-side limb leading. MATERIALS AND METHODS: Sixteen adolescents with severe Lenke 1 AIS (age: 14.9 ± 1.7 years, height: 154.7 ± 5.0 cm) and sixteen healthy controls (age: 14.8 ± 2.7 years, height: 154.9 ± 5.6 cm) each walked and crossed obstacles of 3 heights with either the concave- (AIS-A) or convex-side (AIS-V) limb leading. Angular motions of the trunk, pelvis and lower limbs, and toe-obstacle clearances were measured. Two-way analyses of variance were used to study between-subject (group) and within-subject (limb and height) effects on the variables. Whenever a height effect was found, a polynomial test was used to determine the linear trend. α = 0.05 was set for all tests. RESULTS:Patients with AIS significantly reduced pelvic downward list but increased dorsiflexion in both stance and swing ankles at leading limb crossing when compared to controls (p < 0.05). During AIS-A, additional kinematic modifications were observed, i.e., increased stance hip adduction (4.2 ± 0.8°, p = 0.005) and increased swing knee flexion (12.6 ± 1.4°, p = 0.106), with significantly decreased leading toe-clearance (AIS-A: 121.4 ± 6.7 mm, controls: 140.1 ± 5.6 mm, p = 0.031). CONCLUSIONS:Patients with AIS adopted an altered kinematic strategy for successful obstacle-crossing. With the concave-side limb leading, more joint kinematic modifications with reduced toe-clearance were found when compared to those during the convex-side limb leading, suggesting an increased risk of tripping. Further studies on the kinematic strategies adopted by different types of AIS will be needed for a more complete picture of the functional adaptations in such patient group.