Physiological and methodological aspects of rate of force development assessment in human skeletal muscle

Abstract

Rate of force development (RFD) refers to the ability of the neuromuscular system to increase contractile force from a low or resting level when muscle activation is performed as quickly as possible, and it is considered an important muscle strength parameter, especially for athletes in sports requiring high-speed actions. The assessment of RFD has been used for strength diagnosis, to monitor the effects of training interventions in both healthy populations and patients, discriminate high-level athletes from those of lower levels, evaluate the impairment in mechanical muscle function after acute bouts of eccentric muscle actions and estimate the degree of fatigue and recovery after acute exhausting exercise. Notably, the evaluation of RFD in human skeletal muscle is a complex task as influenced by numerous distinct methodological factors including mode of contraction, type of instruction, method used to quantify RFD, devices used for force/torque recording and ambient temperature. Another important aspect is our limited understanding of the mechanisms underpinning rapid muscle force production. Therefore, this review is primarily focused on (i) describing the main mechanical characteristics of RFD; (ii) analysing various physiological factors that influence RFD; and (iii) presenting and discussing central biomechanical and methodological factors affecting the measurement of RFD. The intention of this review is to provide more methodological and analytical coherency on the RFD concept, which may aid to clarify the thinking of coaches and sports scientists in this area.

Measuring voluntary activation of the Quadriceps femoris during isokinetic concentric contractions

“…In addition, these were focused on RFD during isometric contractions with a few exceptions focusing on RFD during dynamic movements, in any case with maximal effort, only [43,44]. An isolated report suggested that RFD is rather constant once 30% or more of the maximal force is required [45].…”

Rate of force development to evaluate the neuromuscular fatigue and recovery after an intermittent isometric handgrip task with different blood flow restriction conditions

“…We found a significant decline in early and late RFDr (30-200 ms) along 5 minutes after the exercise protocol, independently of blood flow condition. The decline in the early phase of RFDr (i.e, < 100ms) along the five minutes after the IIHE may be justified by alterations in neural factors such as reduction of the motor unit discharge rate 15,16 . Although the applied protocol has no features to induce changes in muscle structure properties, the decrease in the late RFDr after TF may relate to impairment of cross-bridge kinetics 13,28,29 imposed by the accumulation of metabolites, as well as the exercise-induced reactive oxygen/nitrogen species production in the muscle fiber 30 .…”

“…The RFD, which is derived from the force-or torque-time curves recorded during maximal voluntary contractions 14 , have been increasingly used to characterize the capacity for rapid muscle force production in populations including athletes and frail elderly patients 15 . Among reasons for this interest are the facts that (1) it is sensitive to detect acute and chronic changes in neuromuscular function 15 , (2) estimate the degree of fatigue and recovery after acute exhausting exercise 16 and (3) be potentially governed by different physiological features 15,17 , such as neural and muscular (viz., peripheral) mechanisms. Despite the peak force, defined as the maximum force achieved during a maximal muscle effort, independently of the time to achieve it, be a widely used parameter to study muscle performance, there are some limitations with this parameter, when the aim is to investigate the mechanisms involved in the muscle force production capacity 18 , when compared to the RFD.…”

Contractile rate of force development after anterior cruciate ligament reconstruction—a comprehensive review and meta‐analysis

“…23 RFD reflects the ability to produce a high rate of rise in muscle force per unit of time following contraction onset, which can be measured during isometric contraction conditions using force-time or torque-time curves and calculating the average tangential slope between given time points on the curve (eg, at 0-50 ms). 39 In typical activities of daily living (eg, descending stairs, walking fast, or reversing a fall) and athletic movements (eg, sprinting, kicking, and jumping), short-duration muscle contraction times of 50-200 ms are often observed. 39,40 However, when obtained at standardized isometric and optimal length-tension conditions maximal voluntary contraction (MVC) force is not reached until 300-500 ms from the onset of the contraction.…”

“…39 In typical activities of daily living (eg, descending stairs, walking fast, or reversing a fall) and athletic movements (eg, sprinting, kicking, and jumping), short-duration muscle contraction times of 50-200 ms are often observed. 39,40 However, when obtained at standardized isometric and optimal length-tension conditions maximal voluntary contraction (MVC) force is not reached until 300-500 ms from the onset of the contraction. 41 Notably also, the time to reach joint angle and angular velocity-specific MVC torque is shorter for concentric vs eccentric and isometric contractions and decreases as a function of contractile speed.…”