Prof. Dvir comments:

"The work of Maeo et al. was chosen as the first "Paper of the Month" because of its rigorous approach and its high relevance to a topic that is at the heart of isokinetic research, namely the neuromuscular adaptation to concentric vs. eccentric training. This topic was explored by a series of studies from the 1980s with no clear results. One major reason for this situation was the lack of an effective, built-in mechanism to control and adjust the total isokinetic concentric as well as eccentric workload (TAW, in kJ) during the training session, precluding a valid interpretation of the results.

In this new study, in which the knee extensors of one leg were eccentric while the same muscles of the opposite side were trained concentrically, the workload was effectively controlled with a special function of the dynamometer and tuned to the exercising legs.

To measure the physiological and structural fluctuations during the training period, the authors used surface electromyography (EMG) and magnetic resonance imaging (MRI). The protocol was formulated as follows: 10w x 2d x 6set x 10reps at a single speed: 180 ° / s. However, as the eccentric and concentric work had to be adjusted, the number of repetitions within each set was varied as needed. This meant that the total number of repetitions during concentric training was on average almost 40% higher than the number required for the concentric counterpart.

Criticism of the use of isokinetic dynamometry (ISD) in training always refers to the non-functional nature of the movement, the logistical constraint and the cost of the dynamometer. But, in my opinion, the insights gleaned from this study, along with the ability to effectively and accurately control input parameters such as BAM, speed, workload, and contraction intensity, as well as the automation of sentences, repetitions, and execution tempos, combine with unrivaled documentation, by far the limitations mentioned, making isokinetic dynamometry a unique training tool. This is further underpinned by maximum eccentric training, since by definition it can not be done with other mechanical devices"

Read the complete study here
This paper can be purchased directly from the publisher.

Bennet Hundt from ALBA BERLIN Basketball Team training after a fracture of his metatarsus

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Citation

MAEO S, SHAN X, OTSUKA S, KANEHISA H, KAWAKAMI Y. Neuromuscular Adaptations to Work-matched Maximum Eccentric versus Concentric Training. Medicine and Science in Sports and Exercise. 2018; 50 (8): 1629-1640. doi: 10.1249 / MSS.0000000000001611.

The main goal of the PoM initiative is to serve as an update forum for users of isokinetic dynamometry. Recent work on this technology and its applications (usually the last 3 months) are regularly spotted by Prof. Zeevi Dvir. Selected are the studies, which in his opinion represent an important / relevant contribution to the science of isokinetic investigations and conditioning. The selection takes into account the innovation, scientific accuracy and potential applicability of the study without prejudice, underscoring PHYSIOMED's commitment to the highest standards for which it is the world's leading provider of isokinetic technologies.

Prof. Dvir is a member of the Faculty of Physical Therapy at the Sackler Faculty of Medicine, Tel Aviv University, and also works as a non-teaching professor at the Biomechanics and Ergonomics Lab, School of Kinesiology and Health Studies (SKHS), Queen's University, Canada.

Prof. Dvir is an international leader in isokinetics. He is the author of the widely recognized leading title in this area, "Isokinetics: Muscle Testing, Interpretation and Clinical Applications" (Churchill Livingstone, 1st ed., 1995, Elsevier 2nd ed., 2004). Since 1998, he has also been editor-in-chief of Isokinetics and Exercise Science (IOS Press, Amsterdam, The Netherlands), the only international journal devoted to the scientific and practical aspects of technology. Prof. Dvir has published more than 60 papers on isokinetics. He coined the terms Dynamic Control Ratio (DCR), also known as the functional relationship. The DCR has been used mainly in relation to the muscular balance concerning the knee, especially with regard to ACL deficits and reconstruction and is expressed as the ratio Hecc / Qcon. Prof. Dvir was also the first to describe the DCE (difference between the Ecc / Con ratio at high and low speed) to assess the submaximal effort: a core concept in the forensic analysis of muscle weakness. A US patent assigned to him paved the way for a series of publications describing the use of isokinetic tests and short-cycle conditioning.