Active trunk stiffness increases with co-contraction

Agarwal, 1977, Compliance of the human ankle joint, J. Biomech. Eng., 99, 166, 10.1115/1.3426285 Bendat, 2000 Chaffin, 1999, Low-back stresses when learning to use a materials handling device, Ergonomics, 42, 94, 10.1080/001401399185829 Cholewicki, 2000, Effects of external trunk loads on lumbar spine stability, J. Biomech., 33, 1377, 10.1016/S0021-9290(00)00118-4 Crago, 1976, Regulatory actions of human stretch reflex, J. Neurophysiol., 39, 925, 10.1152/jn.1976.39.5.925 Crisco, 1992, Euler stability of the human ligamentous lumbar spine: Part I Theory, Clin. Biomech., 7, 19, 10.1016/0268-0033(92)90003-M Dolan, 1994, Bending and compressive stresses acting on the lumbar spine during lifting activities, J. Biomech., 27, 1237, 10.1016/0021-9290(94)90277-1 Gardner-Morse, 1998, The effects of abdominal muscle coactivation on lumbar spine stability, Spine, 23, 86, 10.1097/00007632-199801010-00019 Gardner-Morse, 1995, Role of muscles in lumbar stability in maximum extension efforts, J. Orthop. Res., 13, 802, 10.1002/jor.1100130521 Gottlieb, 1997, Directional control of planar human arm movement, J. Neurophysiol., 78, 2985, 10.1152/jn.1997.78.6.2985 Granata, 1995, An EMG assisted model of biomechanical trunk loading during free-dynamic lifting, J. Biomech., 28, 1309, 10.1016/0021-9290(95)00003-Z Granata, 1995, The influence of trunk muscle coactivity upon dynamic spinal loads, Spine, 20, 913, 10.1097/00007632-199504150-00006 Granata, 2001, Response of trunk muscle coactivation to changes in spinal stability, J. Biomech., 34, 1117, 10.1016/S0021-9290(01)00081-1 Granata, 2004, Paraspinal muscle reflex dynamics, J. Biomech., 37, 241, 10.1016/S0021-9290(03)00249-5 Granata, 2004, Influence of fatigue in neuromuscular control of spinal stability, Hum. Factors, 46, 81, 10.1518/hfes.46.1.81.30391 Granata, 2001, Trunk posture and spinal stability, J. Biomech., 16, 650, 10.1016/S0268-0033(01)00064-X Granata, 2004, Active stiffness of the ankle in response to inertial and elastic loads, J. Electromyogr. Kinesiol., 14, 599, 10.1016/j.jelekin.2004.03.005 Hunter, 1984, Stiffness–torque–EMG relations at variaous tibialis anterior and triceps surae co-contraction levels optained by real-time feedback of elastic stiffness, Soc. Neurosci. Abstr., 10, 334 Hunter, 1982, Dynamics of human ankle stiffness: variation with mean ankle torque, J. Biomech., 15, 747, 10.1016/0021-9290(82)90089-6 Hunter, 1983, Two-sided linear filter identification, Med. Biol. Eng. Comput., 21, 203, 10.1007/BF02441539 Kearney, 1997, Identification of intrinsic and reflex contributions to human ankle stiffness dynamics, IEEE Trans. Biomed. Eng., 44, 493, 10.1109/10.581944 Kearney, 1990, System identification of human joint dynamics, Crit. Rev. Biomed. Eng., 18, 55 Lacquaniti, 1982, The mechanical behavior of the human forearm in response to the transient perturbations, Biol. Cybern., 44, 35, 10.1007/BF00353954 Ljung, 1998 Ma, 1985, The mechanical response of the active human triceps brachii muscle to very rapid stretch and shortening, J. Biomech., 18, 585, 10.1016/0021-9290(85)90013-2 McGill, 2001, Low back stability: from formal description to issues for performance and rehabilitation, Exer. Sport Sci. Rev., 29, 26, 10.1097/00003677-200101000-00006 Meakin, 1996, Euler buckling as a model for the curvature and flexion of the human lumbar spine, Proc. Roy. Soc. Lond. B, 263, 1383, 10.1098/rspb.1996.0202 K.M. Moorhouse, K.P. Granata, Trunk stiffness and dynamics during active extension exertions, J. Biomech. (in press). K.M. Moorhouse, G. Kaufman, K.P. Granata, Parametric deconvolution for calculation of dynamic trunk stiffness, Int. Soc. Electromyo. Kinesiol., 2004 (Conference Proceeding). Myklebust, 1982, Reciprocal excitation of antagonist muscles as a differentiating feature in spasticity, Ann. Neurol., 12, 367, 10.1002/ana.410120409 Radebold, 2001, Impaired postural control of the lumbar spine is associated with delayed muscle response times in patients with chronic idiopathic low back pain, Spine, 26, 724, 10.1097/00007632-200104010-00004 Simon, 1994 Stokes, 2000, Decrease in trunk muscular response to perturbation with preactivation of lumbar spinal musculature, Spine, 25, 1957, 10.1097/00007632-200008010-00015 Van Dieen, 2003, Trunk muscle recruitment patterns in patients with low back pain enhance the stability of the lumbar spine, Spine, 28, 834, 10.1097/01.BRS.0000058939.51147.55 Zhang, 1997, Simultaneous and nonlinear identification of mechanical and reflex properties of human elbow joint muscles, IEEE Trans. Biomed. Eng., 44, 1192, 10.1109/10.649991