Abstract
To produce successful and safe walking movements, the locomotor control system must have a detailed awareness of the mechanical properties of the lower limbs. Flexibility of this control comes from an ability to identify and accommodate any changes in limb mechanics by updating its internal representation of the lower limb. To explore the ability of the locomotor control system to tune its representation of the lower limb, eight participants performed three 5 min trials (PRE, WEIGHT and POST) of treadmill walking. During the middle trial the participants wore a 2 kg mass around the leg segment of the left lower limb. Joint kinematics and kinetics were determined to assess changes in the walking movements. The modification of limb inertia by adding mass to the limbs (WEIGHT) required a substantive period of adaptation, which lasted between 45 and 50 strides, before individuals fully adjusted to their new lower limb mechanics to achieve steady-state joint kinematics. These movements were caused in part from an increase in hip flexor and knee extensor activity in early swing followed by an increase in hip extensors and knee flexor activity in late swing. Following the removal of the mass (POST), ankle, knee and hip flexion all increased above the levels that were observed in the PRE condition and returned the baseline levels within 20, 70 and 70 strides, respectively. The removal of the mass appeared to cause a greater disruption to walking than the addition of mass to the limb despite a quick return of the joint moments to the PRE condition. Both the changes following the addition of the mass and its subsequent removal may embody a recalibration of the internal limb representation. These changes were characterized by an integrated response consisting of primary recalibration to the modified mechanical parameters and secondary actions to main the integrity of locomotor objectives such as propulsion, balance, support and safe foot trajectories. These recalibration responses were similar to those demonstrated in upper limb movements in response to altered force environments. Understanding this recalibration process will have implications for the prevention of trips and falls as individuals encounter different movement environments or changes to mechanical properties of their limbs, especially for individuals with decreased proprioception or other neural challenges.
Similar content being viewed by others
References
Bouyer LJ, DiZio P, Lackner JR (2003) Adaptive modifications of human locomotion by Coriolis force. In: Proceedings of the 33rd Annual Meeting of the Society for Neuroscience. New Orleans LA
Dempster WT (1955) Space requirements of the seated operator, WADC-TR-55–159, Wright Patterson Air Force Base
Dietz V (2003) Spinal cord pattern generators for locomotion. Clin Neurophysiol 114:1379–1389
Donker SF, Mulder T, Nienhuis B, Duysens J (2002) Adaptations in arm movements for added mass to wrist or ankle during walking. Exp Brain Res 146:26–31
Feldman AG, Latash ML (2005) Testing hypotheses and the advancement of science: recent attempts to falsify the equilibrium point hypothesis. Exp Brain Res 161:91–103
Georgopoulos AP, Grillner S (1989) Visuomotor coordination in reaching and locomotion. Science 245:1209–1210
Ghez C, Sainburg R (1995) Proprioceptive control of interjoint coordination. Canad J Physiol Pharmacol 73:273–284
Gribble PL, Scott SH (2002) Overlap of internal models in motor cortex for mechanical loads during reaching. Nature 417:938–941
Krakauer JW, Ghilardi MF, Ghez C (1999) Independent learning of internal models for kinematic and dynamic control of reaching. Nature Neurosci 2(11):1026–1031
Lam T, Wolstenholme C, Yang JF (2003) How do infants adapt to loading of the limb during the swing phase of locomotion. J Neurophysiol 89:1920–1928
Lackner JR, DiZio P (1994) Rapid adaptation to Coriolis force perturbations of arm trajectory. J Neurophysiol 72(1):299–313
Martin PE, Smith JD, Royer TD (2002) Adaptation in lower extremity joint kinetics to inertial asymmetries during walking. In: Proceedings of 4th world congress of biomechanics
McCrea DA (2001) Spinal circuitry of sensorimotor control of locomotion. J Physiol 533(1):41–50
Noble JW, Prentice SD (2004) Adaptation to unilateral changes in lower-limb mechanical properties during treadmill walking. In: Proceedings of 13th Meeting of Canadian Society for Biomechanics
Palliyath S, Hallett M, Thomas SL, Lebiedowska MK (1998) Gait in patients with cerebellar ataxia. Mov Disord 13(6):958–964
Patla AE, Prentice SD (1995) The role of active forces and intersegmental dynamics in the control of limb trajectory over obstacles during locomotion in humans. Exp Brain Res 106:499–504
Patla AE (1988) Analytic approaches to the study of outputs from central pattern generators. In: Neural control of rhythmic movements in vertebrates. Cohen A (eds) Chap. 12 pp 455–486
Pearson KG (2000) Motor systems. Curr Opin Neurobiol 10:649–654
Prentice SD, Patla AE, Stacey DA (1995) Modelling the time-keeping function of the central pattern generator for locomotion using artificial sequential neural network. Med Biol Eng Comput 33(3):317–322
Prentice SD, Patla AE, Stacey DA (1998) Simple artificial neural network models can generate basic muscle activity patterns for human locomotion at different speeds. Exp Brain Res 123(4):474–480
Reid MJ, Prentice SD (2001) Strategies associated with altered segment parameters during voluntary gait modifications. Neurosci Res Commun 29(2):79–87
Rosenbaum DA, Engelbrecht SE, Bushe MM, Loukopoulos LD (1993) Knowledge model for selecting and producing reaching movements. J Mot Behav 25(3):217–227
Rossignol S (1996) Neural control of stereotypic limb movements. In: Rowell LB, Shepherd JT (eds) Handbook of physiology, Sect. 12. Exercise: regulation and integration of multiple systems American Physiological Society, Bethesda, MA, pp 173–216
Royer TD, Martin PE (2005) Manipulations of leg mass and moment of inertia: effects on energy cost of walking. Med Sci Sport Exerc 37:649–656
Sadeghi H, Allard P, Prince F, Labelle H (2000) Symmetry and limb dominance in able-bodied gait: a review. Gait and Posture 12:35–45
Scott SH (2004) Optimal feedback control and the neural basis of volitional motor control. Nat Rev Neurosci 5(7):532–546
Shadmehr R, Mussa-Ivaldi FA (1994) Adaptive representation of dynamics during learning of a motor task. J Neurosci 5(2):3208–3224
Skinner HB, Barrack RL (1990) Ankle weighting effect on gait in able-bodied adults. Arch Phys Med Rehabil 71:112–115
Winter DA (1991) The biomechanics and control of human gait: normal, pathological, elderly, 2nd edn. Waterloo biomechanics, Waterloo
Zernicke RF, Schneider K, Buford JA (1991) Intersegmental dynamics during gait: implications for control. In: Patla AE (ed) Adaptability of human gait: implications for the control of locomotion. Elsevier, Amsterdam pp 187–202
Acknowledgements
Financial support for this project was provided by NSERC, Canada. Technical assistance from Dr. Milad Ishac and Jeannette Byrne is greatly appreciated.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Noble, J.W., Prentice, S.D. Adaptation to unilateral change in lower limb mechanical properties during human walking. Exp Brain Res 169, 482–495 (2006). https://doi.org/10.1007/s00221-005-0162-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00221-005-0162-3