 |
|
Current program:
Biomechanics of Human Movement
Investigators:
- Mark D. Grabiner, Ph.D.
- Lord, D., M.S.
- Owings, T.M., B.S., M.S.
Collaborators:
- Andrish, J.A., M.D., Department of Orthopaedic Surgery, CCF
- Davis, B.L., Ph.D., Department of Biomedical Engineering, CCF
- Messinger-Rapport, B., M.D., Ph.D., Department of Geriatric Medicine, CCF
- Oas, J., M.D., Department of Otolaryngology, CCF
- Pavol, M.J., Ph.D., Northwestern University
- Weiker, G.G., M.D., Department of Orthopaedic Surgery, CCF
- van den Bogert, A.J., Ph.D., Department of Biomedical Engineering, CCF
Brief Description:
This laboratory investigates central nervous system control of skeletal muscle systems associated with coordinated goal-directed motion of complex, multiple segment motor tasks and the kinetics of those tasks. The investigations fall broadly in the areas of human aging and rehabilitation of orthopaedic-related pathologies.
The Aging Musculoskeletal System
The purposes of this work are to characterize the physiological and biomechanical mechanisms underlying the increased incidence of life and lifestyle-threatening falls in older adults and to design and validate technologies and interventions aimed at reducing this incidence. The approach integrates experimental work on human subjects, mathematical modeling, and optimal control analyses. Two distinct families of large postural perturbations are currently being investigated. The first are those induced by tripping and the second are those associated with slipping, both of which are induced during normal forward locomotion.
Nervous System Control of Eccentric Muscle Contraction
This research is directed at characterizing and explaining the differences between the manner in which the nervous system controls muscle contraction force during two types of contraction, concentric (shortening) and eccentric (lengthening). A mathematical model of a motor unit pool has been developed and in conjunction with experimental work in humans has supported the contention that nervous system control of eccentric contractions differs from that of concentric contraction. Distinct differences in muscle activation during the premovement and movement phases of a contraction have been simulated with the motor unit model and validated with experimentally-derived findings. In part, the differences demonstrate between-muscle structure/function differences.
Rehabilitation of lower extremity disfunction
This research has emphasized the ankle complex and knee joint. Relative to the ankle complex the effort has been directed toward identifying the changes in nervous system control of the musculature associated with the development of chronic ankle complex instability in the absence of ligamentous and structural deficits. At the knee joint, research has targeted the acute and chronic adaptations of the nervous system in response to traumatic injury of the anterior cruciate ligament, an injury that has a high incidence of subsequent degenerative changes in articular cartilage. Patellofemoral syndrome, one of the most common and disabling ailments necessitating clinical intervention has provided a model for the investigation of the efficacy of various clinical interventions, improved interventions, and related technology.
Key References:
Pavol MJ, Owings TM, Foley KT, Grabiner MD: Mechanisms leading to a fall from an induced trip in healthy older adults. Journal of Gerontology: Medical Sciences, in press.
Grabiner PC, Biswas ST, Grabiner MD: Age-related changes of spatial and temporal stride kinematic variability. Archives of Physical Medicine and Rehabilitation, in press.
Nishikawa T, Kurosaka M, Mizuno K, Grabiner MD: Protection and Performance Considerations of Ankle Bracing: A Biomechanical Approach, International Orthopaedics, SICOT, in press.
Grabiner MD, Kasprisin JE: Joint angle-dependencies of elbow flexor activation levels during maximum voluntary isometric and anisometric contractions, Clinical Biomechanics, revision in press.
Grabiner MD: Proprioception and recurrent ankle complex injuries/symptoms. Medicine and Science in Sports and Exercise, 32:1185, 2000.
Brady RA, Pavol MJ, Owings TM, Grabiner MD: Foot displacement but not velocity predicts the outcome of a slip induced in young subjects while walking. Journal of Biomechanics, 33:803-808, 2000.
Fujita I, Nishikawa T, Muratsu H, Andrish JT, Kambic HF, Grabiner MD. ACL-mediated hamstrings reflexes are inadequate to stabilize the knee joint. Journal of Orthopaedic Research, 18:183-189, 2000.
Pavol MJ, Grabiner MD: Knee strength variability between individuals across ranges of motion and hip angles. Medicine and Science in Sports and Exercise, 32:985-992, 2000.
Owings TM, Pavol MJ, Foley KT, Grabiner MD: Measures of postural stability are not predictors of recovery from large postural disturbances in healthy older adults. Journal of the American Geriatrics Society, 48:42-50, 2000.
Ozaki T, Mizuno K, Grabiner MD: Peroneus longus can not be fully activated during ankle complex exercises by uninjured subjects. Kobe Journal of Medical Sciences, 45:119-126, 1999.
Pavol MJ, Owings TM, Foley KT, Grabiner MD: Gait characteristics as risk factors for falling from trips induced in older subjects. Journal of Gerontology: Medical Sciences, 54A:M583-M591, 1999.
Nishikawa T, Grabiner MD: Prophylactic ankle bracing increases the excitability of peroneal muscle motorneurones. Journal of Orthopedic and Sports Physical Therapy, 29:168-173, 1999.
Foley KT , Owings TM, Pavol MJ, Grabiner MD: Maximum grip strength is not related to bone mineral density of the proximal femur in older adults, Calcified Tissue International, 64:291-294,1999.
Grabiner MD, Owings TM: Effects of eccentrically and concentrically induced unilateral fatigue on the involved and uninvolved limbs. Journal of Electromyography and Kinesiology, 9:185-189,1999.
Lundin TM, Jahnigen DW, Grabiner MD: Maximum trunk flexion angle during the sit to stand is not determined by knee or trunk-hip extension strength in healthy older adults. Journal of Applied Biomechanics, 15:233-241, 1999.
Borden LS, Perry JE, Davis BL, Owings TM, Grabiner MD: A biomechanical evaluation of one-stage vs. two-stage bilateral knee arthroplasty patients, Gait and Posture, 9:24-30, 1999.
Pavol MJ, Owings TM, Foley KT, Grabiner MD: The sex and age of older adults influence the outcome of induced trips. Journal of Gerontology: Medical Sciences, 54A:M103-M108, 1999.
Owings TM, Pavol MJ, Foley KT, Grabiner PC, Grabiner MD: Exercise: Is it a solution to falls by older adults?. Journal of Applied Biomechanics, 15:56-63, 1999.