Skeletal Muscle Mechanics

Basics of Skeletal Muscle Mechanics

Skeletal muscles are the motor of the movement. Understanding force production and transmission mechanisms of muscles is the key for identifying and treating musculoskeletal problems. One of our research motivation is to increase the knowledge of the mechanical behavior of healthy and diseased skeletal muscles at different ages under various conditions.

Muscular Interactions

In situ experimental setup. Rat muscle tendons are attached to force transducers in order to measure passive and active muscle forces. Sciatic nerve is supramaximally stimulated for active measurements.

One important gap in muscle research is neglecting the mechanical role of connective tissues. Our experimental tests on rat muscles showed the importance of epimuscular myofascial connections imposing loads between muscles and compartments. We found that the mechanical role of connective tissues is relevant not only on determining the effects of orthopedic surgical interventions but also on muscle paralysis e.g. after botulinum toxin administration. Skeletal muscle physiology and musculoskeletal pathologies such as tumor growth, stroke or therapeutic applications are expected to manipulate myofascial interactions. We investigate these in order to improve the medical treatment approaches.



Ateş F. and Yucesoy C.A., 2018: Botulinum Toxin Type-A Affects Mechanics of Non-injected Antagonistic Rat Muscles. J Mech Behav Biomed Mater. 84: 208-216.

Yucesoy C.A. and Ateş F., 2017: BTX-A Has Notable Effects Contradicting Some Treatment Aims in the Rat Triceps Surae Compartment, Which are not Confined to the Muscles Injected. Journal of Biomechanics. 66: 78-85.

Akdeniz Z., Bayramiçli M., Ateş F., Özkan N., Yucesoy CA., Ercan F., 2015: The role of botulinum toxin type a induced motor endplates following peripheral nerve repair. Muscle & Nerve, 52(3): 412-8.

Ateş, F., Ozdeslik R.N., Huijing P.A., Yucesoy, C.A., 2013: Muscle lengthening surgery causes differential acute mechanical effects in both targeted and non-targeted synergistic muscles. Journal of Electromyography and Kinesiology, 23 (5): 1199-205.

Ateş, F. and Yucesoy, C.A., 2014: Effects of BTX-A on non-injected bi-articular muscle include a narrower length range of force exertion and increased passive force. Muscle & Nerve, 49 (6): 866-878.



Can A. Yucesoy, Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey.

Peter Huijing, Vrije Universitait, Amsterdam, Netherlands.

Huub Maas, Vrije Universitait, Amsterdam, Netherlands.

Tobias Siebert, University of Stuttgart, Stuttgart, Germany.


Direct Measurement of Human Muscle-Tendon Forces

One of the main goals of human locomotion research is to understand the function of a muscle in relation to the joints it crosses. However, direct measurements of individual muscle force with respect to joint position are very rare. Current methods for direct in vivo evaluation of muscle strength are limited to measuring the net torque generated at the joint, which cannot determine the load distribution across the muscles crossing the joint.

Buckle force transducer to measure individual muscle forces directly through the tendon.


Kaya C.S., Bilgili F., Akalan N.E., Temelli Y., Ateş F., Yucesoy C.A. 2019: Intraoperative experiments combined with gait analyses indicate that active state rather than passive dominates the spastic gracilis muscle’s joint movement limiting effect in cerebral palsy. Clin Biomech. 68: 151-157.

Ateş F., Temelli Y., Yucesoy C.A., 2018: Effects of Antagonistic and Synergistic Muscles’ Co-activation on Mechanics of Activated Spastic Semitendinosus in Children with Cerebral Palsy. Human Movement Science. 57: 103-110. 

Kaya C.S., Ateş F., Temelli Y., Yucesoy C.A., 2017: Effects of inter-synergistic mechanical interactions on the mechanical behaviour of activated spastic semitendinosus muscle of patients with cerebral palsy. J Mech Behav Biomed Mater. 77: 78-84.

Yucesoy C.A., Temelli Y., Ateş F., 2017: Intra-operatively Measured Spastic Semimembranosus Forces of Children with Cerebral Palsy. J. Electromyography & Kinesiology. 36: 49-55.

Ateş F., Temelli Y., Yucesoy C.A., 2016: The Mechanics of Activated Semitendinosus are not Representative of the Pathological Knee Joint Condition of Children with Cerebral Palsy. J Electromyography and Kinesiology. 28: 130-6.

Yucesoy, C.A., Turkoglu A.N., Umur S., Ateş F., 2015: Intact muscle compartment exposed to botulinum toxin type A shows comprised intermuscular mechanical interaction. Muscle & Nerve, 51(1): 106-16.

Ateş, F., Temelli Y., Yucesoy, C.A., 2014: Intraoperative experiments show relevance of inter-antagonistic mechanical interaction for spastic muscle’s contribution to joint movement disorder. Clinical Biomechanics, 29(8): 943-9.

Ateş, F., Temelli Y., Yucesoy, C.A., 2013: Human spastic Gracilis muscle isometric forces measured intraoperatively as a function of knee angle show no abnormal muscular mechanics. Clinical Biomechanics, 28: 48-54.

Yucesoy, C.A., Arıkan Ö.E., Ateş F., 2012: BTX-A Administration to the Target Muscle Affects Forces of All Muscles Within an Intact Compartment and Epimuscular Myofascial Force Transmission, J Biomech Eng, 134: 111002-1-9.

Yucesoy, C.A., Ateş F., Akgün, U., Karahan, M., 2010: Measurement of human Gracilis muscle isometric forces as a function of knee angle, intraoperatively. J Biomech, 43 (14): 2665-2671.



Yener Temelli, Istanbul Medical School, Istanbul University, Istanbul, Turkey.

Can A. Yucesoy, Institute of Biomedical Engineering, Bogazici University, Istanbul, Turkey.

Kenton R. Kaufman, Motion Analysis Laboratory, Orthopedic Research, Mayo Clinic, Rochester, MN, USA.

Richard L. Lieber, Shirley Ryan AbilityLab, Chicago, IL, USA.


Estimation of Muscle Force and Mechanical Characterization of Musculoskeletal Structures

1. Intramuscular Pressure

The intramuscular pressure (IMP) is the hydrostatic fluid pressure generated within a muscle. It reflects the generated muscle force. By using micro-scale fiber-optic IMP sensors, we found strong correlations between pressure and active force.

This minimally invasive approach can be used to design as a clinical predictive tool to determine optimal muscle lengths during muscle transfer surgeries, diagnose musculoskeletal diseases, and follow the course of diseases and treatments.


Ateş F., Davies B., Chopra S., Litchy W., Coleman-Wood K., Kaufman K.R., 2019: Intramuscular Pressure of Human Tibialis Anterior Reflects in vivo Muscular Activity. Frontiers in Physiol. 10:196.

Ateş F., Davies B., Chopra S., Litchy W., Coleman-Wood K., Kaufman K.R., 2018: Intramuscular Pressure of Tibialis Anterior Reflects Ankle Torque but does not Follow Joint Angle-Torque Relationship. Frontiers in Physiology. 9: 1-9.



Kenton R. Kaufman, Motion Analysis Laboratory, Orthopedic Research, Mayo Clinic, Rochester, MN, USA.

William Litchy, Neurology, Mayo Clinic, Rochester, MN, USA.


2. Ultrasound Elastography


Ateş F., Andrade R.J., Freitas S.R., Hug F., Lacourpaille L., Yucesoy C.A., Nordez A., 2018: Passive stiffness of monoarticular lower leg muscles is influenced by knee joint angle. Eur J Applied Physiol. 118(3): 585-593.

Ateş F., Hug F, Bouillard K, Jubeau M, Frappart T, Couade M,  Bercoff J, Nordez A., 2015: Muscle Shear Elastic Modulus is Linearly Related to Muscle Torque over the Entire Range of Isometric Contraction Intensity. Journal of Electromyography and Kinesiology, 25(4): 703-8.

Andrade R., Nordez A., Hug F., Ateş F., Coppieters, M.W., Pezerat-Correia P., Freitas S.R., 2015: Non-invasive Assessment of Sciatic Nerve Stiffness during Human Ankle Motion using Ultrasound Shear Wave Elastography. J Biomech, 49(3): 326-31.

Le Sant G., Ateş F., Brasseur J.L., Nordez A., 2015: Elastography Study of Hamstring Behaviors during Passive Stretching. PLOS One, 10 (9): e0139272.



Antoine Nordez, Université de Nantes, Nantes, France

François Hug, Université de Nantes, Nantes, France

Yasuo Kawakami, Waseda University, Tokyo, Japan

Oliver Röhrle, University of Stuttgart, Stuttgart, Germany


Latest conference participations:

  • ISEK 2022, poster session: Zimmer et al., Aging of skeletal muscles: A shear wave elastography approach to detect changes in mechanical properties in vivo
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  • ISEK 2022, oral presentation: Ates et al., Mechanics of Biceps Brachii Muscle in Relation to Elbow Function Using Shear Wave Elastography
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  • VPH 2022, poster session: Zimmer et al., Towards in vivo Passive and Active Muscle Force Estimation using Shear Wave Elastography
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This image shows Filiz Ates

Filiz Ates


Head of Experimental Biomechanics Group

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