Renan A Resende1, Renata N Kirkwood2, Kevin J Deluzio3, Amy M Morton4, Sérgio T Fonseca5. 1. Universidade Federal de Minas Gerais, School of Physical Education, Physical Therapy and Occupational Therapy, Department of Physical Therapy, Avenida Antônio Carlos 6627 Campus Pampulha, Pampulha, 31270-901 Belo Horizonte, MG, Brazil. Electronic address: renanresende@hotmail.com. 2. Wilfrid Laurier University, 75 University Avenue W, Waterloo, ON N2L 3C5, Canada. Electronic address: renata.kirkwood@gmail.com. 3. Queen's University, McLaughlin Hall, Faculty of Engineering and Applied Science, Department of Mechanical and Materials Engineering, Kingston, Ontario, Canada. Electronic address: kevin.deluzio@gmail.com. 4. Queen's University, Human Mobility Research Laboratory, Kingston, Ontario, Canada. Electronic address: amy_morton1@brown.edu. 5. Universidade Federal de Minas Gerais, School of Physical Education, Physical Therapy and Occupational Therapy, Department of Physical Therapy, Avenida Antônio Carlos 6627 Campus Pampulha, Pampulha, 31270-901 Belo Horizonte, MG, Brazil. Electronic address: sergioteixeirafonseca@gmail.com.
Abstract
BACKGROUND: Leg length discrepancy greater than 1cm increases odds of progressive knee osteoarthritis in the shorter limb. METHODS: Biomechanical data of 15 knee osteoarthritis participants were collected while they walked under two conditions: (1) control - wearing thick sandals; (2) short limb - wearing a thin sandal on the osteoarthritic limb and a thick sandal on the contralateral limb. The thick and thin sandals had 1.45cm of thickness difference. The knee osteoarthritis limb was analyzed for both conditions. Ankle, knee, hip, pelvis and trunk kinematics and moments were measured with a motion and force capture system. Principal component analysis and mean hypothesis' tests were used to compare the conditions. FINDINGS: The short limb condition reduced rearfoot plantarflexion in loading response and increased plantarflexion in late stance (p<0.001), increased ankle dorsiflexion moment (p=0.003), increased knee flexion angle in loading response and delayed knee flexion in late stance (p=0.001), increased knee extension moment in loading response and increased knee flexion moment in terminal stance (p=0.023), reduced hip extension moment in early stance and reduced hip flexion moment in late stance (p<0.001), reduced knee adduction moment (p=0.015), reduced hip adduction angle (p=0.001) and moment (p=0.012) and increased pelvic (p=0.023) and trunk (p=0.001) external rotation. INTERPRETATION: Mild leg length discrepancy affects the entire kinetic chain of individuals with knee osteoarthritis during gait, increasing knee sagittal plane loading, which helps to explain why mild leg length discrepancy accelerates knee osteoarthritis progression. Mild leg length discrepancy should not be overlooked in knee osteoarthritis individuals.
BACKGROUND: Leg length discrepancy greater than 1cm increases odds of progressive knee osteoarthritis in the shorter limb. METHODS: Biomechanical data of 15 knee osteoarthritisparticipants were collected while they walked under two conditions: (1) control - wearing thick sandals; (2) short limb - wearing a thin sandal on the osteoarthritic limb and a thick sandal on the contralateral limb. The thick and thin sandals had 1.45cm of thickness difference. The knee osteoarthritis limb was analyzed for both conditions. Ankle, knee, hip, pelvis and trunk kinematics and moments were measured with a motion and force capture system. Principal component analysis and mean hypothesis' tests were used to compare the conditions. FINDINGS: The short limb condition reduced rearfoot plantarflexion in loading response and increased plantarflexion in late stance (p<0.001), increased ankle dorsiflexion moment (p=0.003), increased knee flexion angle in loading response and delayed knee flexion in late stance (p=0.001), increased knee extension moment in loading response and increased knee flexion moment in terminal stance (p=0.023), reduced hip extension moment in early stance and reduced hip flexion moment in late stance (p<0.001), reduced knee adduction moment (p=0.015), reduced hip adduction angle (p=0.001) and moment (p=0.012) and increased pelvic (p=0.023) and trunk (p=0.001) external rotation. INTERPRETATION: Mild leg length discrepancy affects the entire kinetic chain of individuals with knee osteoarthritis during gait, increasing knee sagittal plane loading, which helps to explain why mild leg length discrepancy accelerates knee osteoarthritis progression. Mild leg length discrepancy should not be overlooked in knee osteoarthritis individuals.
Authors: Nurul Azira Azizan; Khairul Salleh Basaruddin; Ahmad Faizal Salleh; Abdul Razak Sulaiman; Muhamad Juhairi Aziz Safar; Wan Mohd Radzi Rusli Journal: J Healthc Eng Date: 2018-06-10 Impact factor: 2.682