Residual force depression following muscle shortening is exaggerated by prior eccentric drop jump exercise

2013 ◽  
Vol 115 (8) ◽  
pp. 1191-1195 ◽  
Author(s):  
Gintare Dargeviciute ◽  
Nerijus Masiulis ◽  
Sigitas Kamandulis ◽  
Albertas Skurvydas ◽  
Håkan Westerblad
Keyword(s):  
Isometric Force ◽  
Knee Extensor ◽  
Mechanical Work ◽  
Muscle Performance ◽  
Eccentric Contractions ◽  
Force Depression ◽  
Jump Exercise ◽  
Before And After ◽  
Drop Jumps ◽  
Residual Force

We studied the relation between two common force modifications in skeletal muscle: the prolonged force depression induced by unaccustomed eccentric contractions, and the residual force depression (rFD) observed immediately after active shortening. We hypothesized that rFD originates from distortion within the sarcomeres and the extent of rFD: 1) correlates to the force and work performed during the shortening steps, which depend on sarcomeric integrity; and 2) is increased by sarcomeric disorganization induced by eccentric contractions. Nine healthy untrained men (mean age 26 yr) participated in the study. rFD was studied in electrically stimulated knee extensor muscles. rFD was defined as the reduction in isometric torque after active shortening compared with the torque in a purely isometric contraction. Eccentric contractions were performed as 50 repeated drop jumps with active deceleration to 90° knee angle, immediately followed by a maximal upward jump. rFD was assessed before and 5 min to 72 h after drop jumps. The series of drop jumps caused a prolonged force depression, which was about two times larger at 20-Hz than at 50-Hz stimulation. There was a significant correlation between increasing rFD and increasing mechanical work performed during active shortening both before and after drop jumps. In addition, a given rFD was obtained at a markedly lower mechanical work after drop jumps. In conclusion, the extent of rFD correlates to the mechanical work performed during active shortening. A series of eccentric contractions causes a prolonged reduction of isometric force. In addition, eccentric contractions exaggerate rFD, which further decreases muscle performance during dynamic contractions.

scholarly journals Modifiability of the history dependence of force through chronic eccentric and concentric biased resistance training

2019 ◽  
Vol 126 (3) ◽  
pp. 647-657 ◽  
Author(s):  
Jackey Chen ◽  
Geoffrey A. Power
Keyword(s):  
Steady State ◽  
Resistance Training ◽  
Isometric Force ◽  
Eccentric Training ◽  
Force Enhancement ◽  
History Dependence ◽  
Force Depression ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Concentric Training

The increase and decrease in steady-state isometric force following active muscle lengthening and shortening are referred to as residual force enhancement (RFE) and force depression (FD), respectively. The RFE and FD states are associated with decreased (activation reduction; AR) and increased (activation increase; AI) neuromuscular activity, respectively. Although the mechanisms have been discussed over the last 60 years, no studies have systematically investigated the modifiability of RFE and FD with training. The purpose of the present study was to determine whether RFE and FD could be modulated through eccentric and concentric biased resistance training. Fifteen healthy young adult men (age: 24 ± 2 yr, weight: 77 ± 8 kg, height: 178 ± 5 cm) underwent 4 wk of isokinetic dorsiflexion training, in which one leg was trained eccentrically (−25°/s) and the other concentrically (+25°/s) over a 50° ankle excursion. Maximal and submaximal (40% maximum voluntary contraction) steady-state isometric torque and EMG values following active lengthening and shortening were compared to purely isometric values at the same joint angles and torque levels. Residual torque enhancement (rTE) decreased by ~36% after eccentric training ( P < 0.05) and increased by ~89% after concentric training ( P < 0.05), whereas residual torque depression (rTD), AR, AI, and optimal angles for torque production were not significantly altered by resistance training ( P ≥ 0.05). It appears that rTE, but not rTD, for the human ankle dorsiflexors is differentially modifiable through contraction type-dependent resistance training. NEW & NOTEWORTHY The history dependence of force production is a property of muscle unexplained by current cross bridge and sliding filament theories. Whether a muscle is actively lengthened (residual force enhancement; RFE) or shortened (force depression) to a given length, the isometric force should be equal to a purely isometric contraction—but it is not! In this study we show that eccentric training decreased RFE, whereas concentric training increased RFE and converted all nonresponders (i.e., not exhibiting RFE) into responders.

Force Recovery After Activated Stretching in Whole Skeletal Muscle: Transient Aspects of Force Enhancement

2008 ◽  
Author(s):  
Ryan A. Koppes ◽  
David T. Corr
Keyword(s):  
Skeletal Muscle ◽  
Steady State ◽  
Isometric Force ◽  
Underlying Mechanism ◽  
Mechanical Work ◽  
Force Enhancement ◽  
Transient Phenomena ◽  
Force Depression ◽  
Force Relaxation ◽  
In Situ Experiments

The enhancement of isometric force after active stretching is a well-accepted and demonstrated characteristic of skeletal muscle in both whole muscle [1,2] and single-fiber preparations [1,3], but its mechanisms remain unknown. Although traditionally analyzed at steady-state, transient phenomena caused, at least in part, by cross-bridge kinetics may provide novel insight into the mechanisms associated with force enhancement (FE). In order to identify the transient aspects of FE and its relation to stretching speed, stretching amplitude, and muscle mechanical work, a post hoc analysis of in situ experiments in soleus muscle tendon units of anesthetized cats [2] was conducted. The period immediately following stretching, at which the force returns to steady-state, was fit using an exponential decay function. The aims of this study were to analyze and quantify the effects of stretching amplitude, stretching speed, and muscle mechanical work on steady-state force enhancement (FEss) and transient force relaxation rate after active stretching. The results of this study were interpreted with respect to prior force depression (FD) experiments [4], to identify if the two phenomena exhibited similar transient and steady-state behaviors, and thus could be described by the same underlying mechanism(s).

scholarly journals The influence of training-induced sarcomerogenesis on the history dependence of force

2020 ◽  
Vol 223 (15) ◽  
pp. jeb218776 ◽  
Author(s):  
Jackey Chen ◽  
Parastoo Mashouri ◽  
Stephanie Fontyn ◽  
Mikella Valvano ◽  
Shakeap Elliott-Mohamed ◽  
...  
Keyword(s):  
Extensor Digitorum Longus ◽  
Isometric Force ◽  
Muscle Length ◽  
Force Enhancement ◽  
Active Muscle ◽  
Training Groups ◽  
Force Depression ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Whole Muscle

ABSTRACTThe increase or decrease in isometric force following active muscle lengthening or shortening, relative to a reference isometric contraction at the same muscle length and level of activation, are referred to as residual force enhancement (rFE) and residual force depression (rFD), respectively. The purpose of these experiments was to investigate the trainability of rFE and rFD on the basis of serial sarcomere number (SSN) alterations to history-dependent force properties. Maximal rFE/rFD measures from the soleus and extensor digitorum longus (EDL) of rats were compared after 4 weeks of uphill or downhill running with a no-running control. SSN adapted to the training: soleus SSN was greater with downhill compared with uphill running, while EDL demonstrated a trend towards more SSN for downhill compared with no running. In contrast, rFE and rFD did not differ across training groups for either muscle. As such, it appears that training-induced SSN adaptations do not modify rFE or rFD at the whole-muscle level.

Fatigue and muscle–tendon stiffness after stretch–shortening cycle and isometric exercise

2006 ◽  
Vol 31 (5) ◽  
pp. 565-572 ◽  
Author(s):  
Hechmi Toumi ◽  
Georges Poumarat ◽  
Thomas M. Best ◽  
Alain Martin ◽  
John Fairclough ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Isometric Force ◽  
Isometric Exercise ◽  
Isometric Contractions ◽  
Jump Performance ◽  
Tendon Stiffness ◽  
Before And After ◽  
Drop Jumps ◽  
Stretch Shortening Cycle ◽  
Knee Muscle

The purpose of the present study was to compare vertical jump performance after 2 different fatigue protocols. In the first protocol, subjects performed consecutive sets of 10 repetitions of stretch–shortening cycle (SSC) contractions. In the second protocol, successive sets of 10 repetitions of isometric contractions were performed for 10 s with the knee at 90° of flexion. The exercises were stopped when the subjects failed to reach 50% of their maximum voluntary isometric contractions. Maximal isometric force and maximal concentric power were assessed by performing supine leg presses, squat jumps, and drop jumps. Surface EMG was used to determine changes in muscle activation before and after fatigue. In both groups, the fatigue exercises reduced voluntary isometric force, maximal concentric power, and drop jump performance. Kinematic data showed a decrease in knee muscle–tendon stiffness accompanied by a lengthened ground contact time. EMG analysis showed that the squat and drop jumps were performed similarly before and after the fatigue exercise for both groups. Although it was expected that the stiffness would decrease more after SSC than after isometric fatigue (as a result of a greater alteration of the reflex sensitivity SSC), our results showed that both protocols had a similar effect on knee muscle stiffness during jumping exercises. Both fatigue protocols induced muscle fatigue, and the decrease in jump performance was linked to a decrease in the strength and stiffness of the knee extensor muscles.

Force recovery after activated shortening in whole skeletal muscle: transient and steady-state aspects of force depression

2005 ◽  
Vol 99 (1) ◽  
pp. 252-260 ◽  
Author(s):  
David T. Corr ◽  
Walter Herzog
Keyword(s):  
Skeletal Muscle ◽  
Steady State ◽  
Isometric Force ◽  
Mechanical Work ◽  
Transient Phenomena ◽  
Cross Bridge ◽  
Force Depression ◽  
In Situ Experiments ◽  
Force Recovery ◽  
Cross Bridges

The depression of isometric force after active shortening is a well-accepted characteristic of skeletal muscle, yet its mechanisms remain unknown. Although traditionally analyzed at steady state, transient phenomena caused, at least in part, by cross-bridge kinetics may provide novel insight into the mechanisms associated with force depression (FD). To identify the transient aspects of FD and its relation to shortening speed, shortening amplitude, and muscle mechanical work, in situ experiments were conducted in soleus muscle-tendon units of anesthetized cats. The period immediately after shortening, in which force recovers toward steady state, was fit by using an exponential recovery function ( R2 > 0.99). Statistical analyses revealed that steady-state FD (FDss) increased with shortening amplitude and mechanical work. This FDss increase was always accompanied by a significant decrease in force recovery rate. Furthermore, a significant reduction in stiffness was observed after all activated shortenings, presumably because of a reduced proportion of attached cross bridges. These results were interpreted with respect to the two most prominent proposed mechanisms of force depression: sarcomere length nonuniformity theory ( 7 , 32 ) and a stress-induced inhibition of cross-bridge binding in the newly formed actin-myosin overlap zone ( 14 , 28 ). We hypothesized that the latter could describe both steady-state and transient aspects of FD using a single scalar variable, the mechanical work done during shortening. As either excursion (overlap) or force (stress) is increased, mechanical work increases, and cross-bridge attachment would become more inhibited, as supported by this study in which an increase in mechanical work resulted in a slower recovery to a more depressed steady-state force.

scholarly journals Shortening-induced residual force depression in humans

2019 ◽  
Vol 126 (4) ◽  
pp. 1066-1073 ◽  
Author(s):  
Jackey Chen ◽  
Daniel Hahn ◽  
Geoffrey A. Power
Keyword(s):  
Positive Relationship ◽  
Isometric Force ◽  
Muscle Length ◽  
Experimental Models ◽  
Force Depression ◽  
Current Review ◽  
Isometric Muscle Contraction ◽  
Residual Force ◽  
Muscle Groups ◽  
Isometric Muscle

When an isometric muscle contraction is immediately preceded by an active shortening contraction, a reduction in steady-state isometric force is observed relative to an isometric reference contraction at the same muscle length and level of activation. This shortening-induced reduction in isometric force, termed “residual force depression” (rFD), has been under investigation for over a half century. Various experimental models have revealed the positive relationship between rFD and the force and displacement performed during shortening, with rFD values ranging from 5 to 39% across various muscle groups, which appears to be due to a stress-induced inhibition of cross-bridge attachments. The current review will discuss the findings of rFD in humans during maximal and submaximal contractions.

scholarly journals The influence of training-induced sarcomerogenesis on the history dependence of force

2020 ◽  
Author(s):  
Jackey Chen ◽  
Parastoo Mashouri ◽  
Stephanie Fontyn ◽  
Mikella Valvano ◽  
Shakeap Elliott-Mohamed ◽  
...  
Keyword(s):  
Isometric Force ◽  
Muscle Length ◽  
Force Enhancement ◽  
Force Depression ◽  
Summary Statement ◽  
Residual Force ◽  
Residual Force Enhancement ◽  
Whole Muscle ◽  
Insight Into ◽  
Sarcomere Number

AbstractThe increase or decrease in isometric force following active muscle lengthening or shortening, relative to a reference isometric contraction at the same muscle length and level of activation, are referred to as residual force enhancement (rFE) and residual force depression (rFD), respectively. The purpose of these experiments was to gain further mechanistic insight into the trainability of rFE and rFD, on the basis of serial sarcomere number (SSN) alterations to length-dependent properties. Maximal rFE/rFD measures from the soleus and extensor digitorum longus (EDL) of rats were compared after 4 weeks of uphill/downhill running and a no running control. Serial sarcomere numbers adapted to the training: soleus serial sarcomere number was greater with downhill compared to uphill running, while EDL demonstrated a trend towards more serial sarcomeres for downhill compared to no running. In contrast, absolute and normalized rFE/rFD did not differ across training groups for either muscle. As such, it appears that training-induced SSN adaptations do not modify rFE/rFD at the whole-muscle level.Summary StatementThe addition and subtraction of serial sarcomeres induced by downhill and uphill running, respectively, did not influence the magnitude of stretch-induced force enhancement and shortening-induced force depression.

scholarly journals Walking time measures for evaluating OA of the knee

2019 ◽  
Vol 50 (1) ◽  
pp. 5-8
Author(s):  
R. Marks
Keyword(s):  
Functional Performance ◽  
Intraclass Correlation ◽  
Knee Extensor ◽  
Quadriceps Strength ◽  
Knee Extensor Strength ◽  
Before And After ◽  
Walking Tests ◽  
Experimental Subjects ◽  
Test Retest Reliability ◽  
Walking Time

This study assessed the test-retest reliability and the sensitivity of self-paced walking time measurements for evaluating the functional performance of persons with knee osteoarthritis (OA). The 13 m timed walking tests were carried out on two separate occasions over a six-week period for 10 patients using a standardised protocol. The same measurements were recorded also for three additional patients before and after a six-week quadriceps strength training regimen. As indicated by an intraclass correlation coefficient of 0.83 with no significant intersession test differences for the group (P=0.98), the gait measurements were reliable. However, despite marked increase in knee extensor strength and significant subjective improvements in walking time for the three experimental subjects were smaller than the error of measurement. The findings suggest that regardless of reliability, measurements of self-paced level walking time might not be sufficiently sensitive for evaluating longitudinal changes in functional performance in this patient population.

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