Dynamic Stabilization Time After Isokinetic and Functional Fatigue.

OBJECTIVE: To compare the effects of an isokinetic fatigue protocol and a functional fatigue protocol on time to stabilization (TTS), ground reaction force (GRF), and joint kinematics during a jump landing. DESIGN AND SETTING: Subjects were assessed on 2 occasions for TTS, GRF, and joint kinematics immediately before and after completing a fatigue protocol. One week separated the 2 sessions, and the order of fatigue protocols was randomly assigned and counterbalanced. SUBJECTS: Twenty healthy male (n = 8, age = 21.8 +/- 1.4 years, height = 180.6 +/- 7.6 cm, and mass = 74.1 +/- 13.0 kg) and female (n = 12, age = 22.2 +/- 2.1 years, height = 169.3 +/- 9.8 cm, and mass = 62.5 +/- 10.1 kg) subjects volunteered to participate. MEASUREMENTS: Subjects performed 2-legged jumps equivalent to 50% of maximum jump height, followed by a single-leg landing onto the center of a forceplate 70 cm from the starting position. Peak vertical GRF and vertical, medial-lateral, and anterior-posterior TTS were obtained from forceplate recordings. Maximum ankle dorsiflexion, knee-flexion, and knee-valgum angles were determined using 3-dimensional motion analysis. RESULTS: A 2-way analysis of variance with repeated measures revealed no significant differences when comparing TTS, GRF, and joint kinematics after isokinetic and functional fatigue protocols. CONCLUSIONS: No difference was noted between isokinetic and functional fatigue protocols relative to dynamic stability when landing from a jump.

[1]  Antonio Pedotti,et al.  Motor strategies in landing from a jump: the role of skill in task execution , 2004, Experimental Brain Research.

[2]  Susan Goodwin Gerberich,et al.  Analysis of Severe Injuries Associated with Volleyball Activities. , 1987 .

[3]  T. Hortobágyi,et al.  Foot placement modifies kinematics and kinetics during drop jumping. , 1999, Medicine and science in sports and exercise.

[4]  Normand Teasdale,et al.  Alteration of the position sense at the ankle induced by muscular fatigue in humans. , 2002, Medicine and science in sports and exercise.

[5]  H Johansson,et al.  Localized muscle fatigue decreases the acuity of the movement sense in the human shoulder. , 1999, Medicine and science in sports and exercise.

[6]  H. Skinner,et al.  Effect of fatigue on joint position sense of the knee , 1986, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[7]  M. Garrett,et al.  Functional Instability of the Ankle: Differences in Patterns of Ankle and Knee Movement Prior To and Post Landing in a Single Leg Jump , 2002, International journal of sports medicine.

[8]  R. B. Johnston,et al.  Effect of lower extremity muscular fatigue on motor control performance. , 1998, Medicine and science in sports and exercise.

[9]  B T Bates,et al.  Contributions of lower extremity joints to energy dissipation during landings. , 2000, Medicine and science in sports and exercise.

[10]  P. Devita,et al.  Effect of landing stiffness on joint kinetics and energetics in the lower extremity. , 1992, Medicine and science in sports and exercise.

[11]  Alf Thorstensson,et al.  Central and peripheral contributions to fatigue in relation to level of activation during repeated maximal voluntary isometric plantar flexions. , 2004, Journal of applied physiology.

[12]  S. Lephart,et al.  Functional rehabilitation for the upper and lower extremity. , 1995, The Orthopedic clinics of North America.

[13]  J Ekstrand,et al.  Soccer injuries and their mechanisms: a prospective study. , 1983, Medicine and science in sports and exercise.

[14]  Scott M Lephart,et al.  The Sensorimotor System, Part II: The Role of Proprioception in Motor Control and Functional Joint Stability. , 2002, Journal of athletic training.

[15]  R. Blasier,et al.  The Effects of Muscle Fatigue on Shoulder Joint Position Sense , 1998, The American journal of sports medicine.

[16]  C. Mattacola,et al.  Effect of orthotics on postural sway after fatigue of the plantar flexors and dorsiflexors. , 2000, Journal of athletic training.

[17]  J B Myers,et al.  Proprioception and neuromuscular control of the shoulder after muscle fatigue. , 1999, Journal of athletic training.

[18]  J. Agel,et al.  Anterior cruciate ligament injury patterns among collegiate men and women. , 1999, Journal of athletic training.

[19]  K. M. Jackson,et al.  Fitting of Mathematical Functions to Biomechanical Data , 1979, IEEE Transactions on Biomedical Engineering.

[20]  Scott E. Ross,et al.  RESEARCH DIGEST Time to Stabilization: A Method for Analyzing Dynamic Postural Stability , 2003 .

[21]  J. Yaggie,et al.  Effects of isokinetic ankle fatigue on the maintenance of balance and postural limits. , 2002, Archives of physical medicine and rehabilitation.

[22]  J. Taunton,et al.  A Survey of Injuries to the Anterior Cruciate Ligament of the Knee in Female Basketball Players , 1985, International journal of sports medicine.

[23]  M. Torry,et al.  Lower limb stability with ACL impairment. , 1999, The Journal of orthopaedic and sports physical therapy.

[24]  A. K. Aune,et al.  Hamstrings and gastrocnemius co‐contraction protects the anterior cruciate ligament against failure: An in vivo study in the rat , 1995, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[25]  Harry Prapavessis,et al.  Decreasing landing forces: effect of instruction , 2000, British journal of sports medicine.

[26]  T. A. Blackburn,et al.  The effects of muscle fatigue on and the relationship of arm dominance to shoulder proprioception. , 1996, The Journal of orthopaedic and sports physical therapy.

[27]  Jane A. Kent-Braun,et al.  Central and peripheral contributions to muscle fatigue in humans during sustained maximal effort , 1999, European Journal of Applied Physiology and Occupational Physiology.