Applied Sports Sciences (AP)

Muscle Strength Measurement for Applications in Sport and Rehabilitation

26.09.2023, 15:00 CET

The accurate measurement of muscle strength and muscle-tendon mechanical properties are very important in a range of Sport, Exercise and Clinical Rehabilitation applications. However, there are a number of issues when using isokinetic, isometric, hand-held or other strain gauge-based dynamometry devices that affect the measurement of muscle strength. These stem mainly from not following the recommended guidelines and/or not considering the mechanical principles of measuring muscle function and mechanics with these devices. These problems are compounded by the dynamics and complexity of the structure and function of muscle-tendon units in the musculoskeletal system. For these reasons, it is extremely important to consider all the above issues and the related biomechanical principles when measuring muscle strength and muscle-tendon mechanics. This ECSS webinar will describe in detail these issues and problems when measuring muscle strength and will provide clear advice and recommendations for the accurate assessment of muscle strength for sport performance and injury prevention and rehabilitation applications.

Chaired by

Webinar Chair
Prof. V. Baltzopoulos,
Head of the Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University, United Kingdom
Webinar Speaker
Prof. Per Aagaard, PhD
Department of Sports Science and Clinical Biomechanics, Research Unit for Muscle Physiology and Biomechanics,
University of Southern Denmark, Odense M, Denmark
"Skeletal muscle strength assessment in sports and clinical practice: Methodological aspects, effects of resistance training and relationships to performance”"

Maximal contractile muscle strength can be evaluated in vivo using isokinetic and non-isokinetic dynamometers during single and multi-joint muscle actions. Isokinetic dynamometry is highly versatile for the assessment of maximal eccentric muscle strength in vivo. In many settings (i.e. elite sports, injury rehabilitation and prevention, geriatrics, fall prevention) it is also of importance to evaluate rapid force capacity often termed explosive muscle strength, which is defined as the rate of force development (RFD) in the early phase of muscle contraction (0-200 ms) obtained using isokinetic or static dynamometry. This talk will present examples of strength and RFD measurements performed in athletes and various patient groups, and discuss the effect of resistance-based exercise training on these parameters. Also, relationships to functional performance will be presented and discussed.

Webinar Speaker
Prof. A. Arampatzis, PhD
Department of Training and Movement Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
"“Accurate diagnosis of tendon mechanical properties for personalized tendon loading”

It has been long recognized that the functional properties of muscles are a crucial determinant of movement performance in both every day and athletic activities. In comparison, we just recently began to understand how tendons influence muscle-tendon unit functioning and performance. The interaction of muscle and tendon is of major importance for movement performance and a balanced development of muscle strength and tendon stiffness could protect athletes from overuse injury. The development of a diagnostic routine to assess both the strength capacity of muscle and the mechanical properties of tendons would enable the detection of muscle-tendon imbalances, indicate if the training should target muscle strength or tendon stiffness development and allow for the precise prescription of training loads to optimize tendon adaptation. This presentation will discuss methodological aspects for an accurate measurement of the Achilles and patellar tendon mechanical properties and a framework of personalized muscle-tendon assessment and training.

Webinar Speaker
Prof. Eleftherios Kellis, PhD
Laboratory of Neuromechanics, Department of Physical Education and Sport Science at Serres, School of P.E.and Sport Science, Aristotle University of Thessaloniki, Serres, Greece
“Hamstring architecture and strength measurements”

The hamstring muscles are a group of muscles that have important but variable effects on movements requiring hip and knee joint motion. Alterations in hamstring muscle function are often associated with ligamentous injuries, back pain problem whilst injuries to the muscles themselves represent a very common injury in sports. The purpose of this talk is to present current information on hamstring architecture and strength measurements. The first part will discuss important methodological issues when quantifying architecture of the hamstrings and then identify important inter-muscular and intra-muscular variations in hamstring architecture. The second part will present common methods for measuring hamstring muscle strength as a function of hip and knee angle and then, relate force/torque generation with architecture of these muscles using mathematical simulation.

Webinar Speaker
Prof. V. Baltzopoulos, PhD FBASES
Head of the Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University (LJMU), Liverpool, UK
"The importance of skeletal gearing when measuring muscle strength"

Human movement is the result of joint rotations generated by the application of muscle moments. Since moment is the product of force and moment arm, the leverage of the muscle force application in relation to the lever of the external force applied or measured (skeletal gearing) must always be considered when measuring muscle strength. Muscle moment arms also play an important role for muscle function. For a given joint rotation, they dictate muscle length and shortening velocity, which in turn determine muscle force generation and transmission to the skeleton to produce movement. Problems and errors occur when using dynamometers without considering the mechanics of these measurements. This presentation will focus on axes misalignment, biarticular muscle contributions and using hand-held dynamometry and other strain-gauge based devices that simply measure force along a limb without considering the moment arms of the measuring device and the assessed muscle group(s). These problems result in flawed measurements and incorrect assessment of muscle strength.