Quantification of Achilles Tendon Force Enhancement by Passively Induced Dorsiflexion Stretches

Magnitude of the reflex contribution to force enhancement was investigated in vivo during passive stretches of the Achilles tendon (AT) of one female subject. Thirty passive (5 × 6) dorsiflexions were induced by a motorized ankle ergometer. Achilles tendon force (ATF) was sensed by a buckle transducer applied surgically around the right AT. Single passive stretches resulted in a low but rather linear ATF increase in the absence of EMG (surface electrodes) activity. In the presence of reflexes, a clear ATF enhancement occurred 13–15 ms after the beginning of the EMG reflex responses. In double dorsiflexions at either 1.2 or 1.9 rad · s-1, which were separated by a maintained stretched position of either 40 or 90 ms, the first stretch resulted in initial linear ATF increase, followed by an additional force enhancement during the plateau phase. This reflexly induced increase represented 94 ± 4 N and 184 ± 1 N, respectively, for the 40 and the 90 ms plateaus, corresponding to 210 ± 85% and 486 ± 177% enhancem...

[1]  R. Gregor,et al.  A comparison of the triceps surae and residual muscle moments at the ankle during cycling. , 1991, Journal of biomechanics.

[2]  M Miyashita,et al.  Comparison between the directly measured achilles tendon force and the tendon force calculated from the ankle joint moment during vertical jumps. , 1993, Clinical biomechanics.

[3]  P. Komi,et al.  In vivo registration of Achilles tendon forces in man. I. Methodological development. , 1987, International journal of sports medicine.

[4]  J. Houk,et al.  Improvement in linearity and regulation of stiffness that results from actions of stretch reflex. , 1976, Journal of neurophysiology.

[5]  P. Komi.  Relevance of in vivo force measurements to human biomechanics. , 1990, Journal of biomechanics.

[6]  K. Edman,et al.  The role of non-uniform sarcomere behaviour during relaxation of striated muscle. , 1980, European heart journal.

[7]  R MARGARIA,et al.  EFFECT OF NEGATIVE WORK ON THE AMOUNT OF POSITIVE WORK PERFORMED BY AN ISOLATED MUSCLE. , 1965, Journal of applied physiology.

[8]  M. Noble,et al.  Enhancement of mechanical performance by stretch during tetanic contractions of vertebrate skeletal muscle fibres. , 1978, The Journal of physiology.

[9]  P. Komi,et al.  Biomechanical loading of Achilles tendon during normal locomotion. , 1992, Clinics in sports medicine.

[10]  R. Gregor,et al.  In vivo moment arm calculations at the ankle using magnetic resonance imaging (MRI). , 1990, Journal of biomechanics.

[11]  V. Dietz,et al.  Regulation of Muscle Stiffness in Human Locomotion , 1984, International journal of sports medicine.

[12]  Alan J. McComas,et al.  Skeletal Muscle: Form and Function , 1996 .

[13]  P. Komi.  Measurement of the Force-Velocity Relationship in Human Muscle under Concentric and Eccentric Contractions , 1973 .

[14]  A. McComas,et al.  Fast and slow twitch muscles in man. , 1968, Journal of the neurological sciences.

[15]  A. McComas,et al.  Influence of joint position on ankle plantarflexion in humans. , 1982, Journal of applied physiology: respiratory, environmental and exercise physiology.

[16]  A. Levin,et al.  The Viscous Elastic Properties of Muscle , 1927 .