Association between energy cost of walking, muscle activation, and biomechanical parameters in older female fallers and non-fallers

• Published in: Clinical biomechanics (Bristol) 2013-03, Vol.28 (3), p.330-336
• Main Authors: Marques, Nise Ribeiro, LaRoche, Dain Patrick, Hallal, Camilla Zamfolini, Crozara, Luciano Fernandes, Morcelli, Mary Hellen, Karuka, Aline Harumi, Navega, Marcelo Tavella, Gonçalves, Mauro
• Format: Article
• Language: English
• Subjects: Accidental Falls; Aged; Aged, 80 and over; Aging; Ankle Joint - physiology; Biomechanical Phenomena; Electromyography; EMG; Energy Metabolism - physiology; Fall risk; Female; Gait; Gait - physiology; Hip Joint - physiology; Humans; Kinematic; Knee Joint - physiology; Middle Aged; Muscle Strength - physiology; Muscle, Skeletal - physiology; Oxygen Consumption; Physical Medicine and Rehabilitation; Range of Motion, Articular - physiology; Torque; Walking - physiology
• ISSN: 0268-0033; 1879-1271
• DOI: 10.1016/j.clinbiomech.2013.01.004

Abstract Objective To determine the nervous activation, muscle strength, and biomechanical parameters that influence the cost of walking in older fallers and non-fallers. Methods Maximal voluntary isokinetic torque was measured for the hip, knee and ankle of older women. Oxygen consumption was measured at rest and during 8 min of walking at self-selected speed. An additional minute of walking was performed to collect kinematic variables and the electromyographic signal of trunk, hip, knee, and ankle muscles, which was analyzed by the linear envelope. Cost of walking was calculated by subtracting resting body mass-normalized oxygen consumption from walking body mass-normalized oxygen consumption. Stride time and length, and ankle and hip range of motion were calculated from kinematic data. Findings Older adult fallers had 28% lower knee extensor strength ( p = 0.02), 47% lower internal oblique activation at heel contact ( p = 0.03), and higher coactivation between tibialis anterior and gastrocnemius lateralis in each of the gait phases ( p < 0.05). For fallers, a higher activation of gluteus maximus was associated with a higher cost of walking ( r = 0.55, p < 0.05 and r = 0.71, p < 0.01, before and after heel contact, respectively). For non-fallers, an association between cost of walking and age ( r = 0.60, p = 0.01) and cost of walking and thigh muscle coactivation ( r = 0.53, p = 0.01) existed. Interpretation This study demonstrated that there may be links between lower-extremity muscle weakness, muscle activation patterns, altered gait, and increased cost of walking in older fallers.