The relation between force and velocity in human muscle
Force and velocity are two related but different concepts in basic physics. Their relationship is one of the first things that physics students learn. Sachs LJ, Angrist A. Congenital Cyst of the Myocardium. Am J Pathol. Jan; 21(1)– [PMC free article] [PubMed]; Fenn WO, Marsh BS. Muscular. The force velocity relationship is the observation that muscle force and contraction velocity are inversely related. In shortening (concentric) muscle actions.
Canadian Journal of Applied Physiology, 27 3 Effects of velocity of isokinetic training on strength, power, and quadriceps muscle fibre characteristics. The effects of eccentric and concentric training at different velocities on muscle hypertrophy. European Journal of Applied Physiology, 89 6 Muscular force at different speeds of shortening. The Journal of Physiology, 85 3 A comparison of the kinematics, kinetics and muscle activity between pneumatic and free weight resistance.
European Journal of Applied Physiology, 6 Journal of Applied Biomechanics.
Interdependence of torque, joint angle, angular velocity and muscle action during human multi-joint leg extension. Muscle fascicle shortening behaviour of vastus lateralis during a maximal force—velocity test.
European Journal of Applied Physiology, The heat of shortening and the dynamic constants of muscle. Proceedings of the Royal Society of London B: Biological Sciences, Role of concentric force in limiting improvement in muscular strength.
Journal of Applied Physiology, 68 2 Effects of load and contraction velocity during three-week biceps curls training on isometric and isokinetic performance.
International Journal of Sports Medicine. Comparison of treadmill and cycle ergometer measurements of force-velocity relationships and power output.
Force velocity relationship
International Journal of Sports Medicine, 20 3 Effect of countermovement on power—force—velocity profile.
European Journal of Applied Physiology, 11 Effectiveness of an individualized training based on force-velocity profiling during jumping. Frontiers in Physiology, 7, Training effect of different loads on the force-velocity relationship and mechanical power output in human muscle. Scandinavian Journal of Sports Science, 5 2 Specificity of speed of exercise. Physical Therapy, 50 12 Direct measurement of power during one single sprint on treadmill.
CV Physiology: Force-Velocity Relationship
Journal of Biomechanics, 43 10 Effects of maximal effort strength training with different loads on dynamic strength, cross-sectional area, load-power and load-velocity relationships.
Age-and sex-related differences in force-velocity characteristics of upper and lower limbs of competitive adolescent swimmers. Journal of Human Kinetics, 32, The effectiveness of a mini-cycle on velocity-specific strength acquisition. The y-intercept represents an extrapolated value for the maximal velocity of shortening Vmax that would be achieved if there were no afterload. The value was extrapolated by Sonnenblick because it cannot be measured experimentally because the papillary muscle preparation cannot contract without a finite preload, which becomes the afterload during shortening in the absence of an additional afterload.
It is important to note that a cardiac muscle fiber does not operate on a single force-velocity curve. This relationship is altered by changes in both preload and inotropy.
File:Muscle Force Velocity relationship.png
The former shares some similarities with skeletal muscle; the latter, however, is unique to cardiac muscle. How Preload Affects the Force-Velocity Relationship If preload is increased, cardiac muscle fibers will have a greater velocity of shortening at a given afterload see figure. Conversely, if preload decreases, the velocity of shortening decreases at a given afterload.
This occurs because the length-tension relationship dictates that as the preload is increased, there is an increase in active tension development.
Once the fiber begins to shorten, the increased tension generating capability at the increased preload results in a greater velocity of shortening. In other words, increasing the preload enables to muscle to contract faster against a given afterload.
Note that increasing preload increases the maximal isometric force Fmaxas well as increases the shortening velocity at a given afterload, but does not alter not alter Vmax.