Effects of stimulation frequencies and patterns on performance of repetitive, nonisometric tasks

2002 ◽  
Vol 92 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Maikutlo B. Kebaetse ◽  
Amanda E. Turner ◽  
Stuart A. Binder-Macleod
Keyword(s):  
Isometric Force ◽  
Knee Extension ◽  
Variable Frequency ◽  
Constant Frequency ◽  
Human Knee ◽  
Target Angle ◽  
Single Pattern ◽  
The Subject ◽  
Stimulation Pattern ◽  
Quadriceps Femoris Muscles

The purpose of this paper was to determine the effects of stimulation pattern and frequency on repetitive human knee movements. Quadriceps femoris muscles were stimulated against a load equal to 10% of each subject's maximum voluntary isometric force. The main variable of interest was the number of repetitions in which the leg reached a target angle of 40° of knee extension. Sixteen different trains were tested, including 1) six constant-frequency trains with frequencies ranging from 9 to 100 Hz, 2) five variable-frequency trains with an initial 5-ms triplet and mean frequencies ranging from 11 to 35 Hz, and 3) five doublet-frequency trains, which used doublets (2 pulses with a 5-ms interpulse interval) to replace single pulses, with mean frequencies of 17–57 Hz. Testing was stopped when the subject failed to reach the target angle for three consecutive activations. Results showed that no single pattern was best for all subjects. The 33- and 100-Hz constant-frequency trains, 35-Hz variable-frequency trains, and 27- and 36-Hz doublet frequency trains each met the target the most times for some subjects. The results showed that, under our testing conditions, higher frequency trains were better suited for producing repetitive knee movements than lower frequency trains.

Effects of activation frequency and force on low-frequency fatigue in human skeletal muscle

1999 ◽  
Vol 86 (4) ◽  
pp. 1337-1346 ◽  
Author(s):  
Stuart A. Binder-Macleod ◽  
David W. Russ
Keyword(s):  
Healthy Subjects ◽  
Human Skeletal Muscle ◽  
Low Frequency ◽  
Variable Frequency ◽  
Activation Pattern ◽  
Constant Frequency ◽  
Mean Frequency ◽  
Before And After ◽  
Low Frequency Fatigue ◽  
Force Time

No comparison of the amount of low-frequency fatigue (LFF) produced by different activation frequencies exists, although frequencies ranging from 10 to 100 Hz have been used to induce LFF. The quadriceps femoris of 11 healthy subjects were tested in 5 separate sessions. In each session, the force-generating ability of the muscle was tested before and after fatigue and at 2, ∼13, and ∼38 min of recovery. Brief (6-pulse), constant-frequency trains of 9.1, 14.3, 33.3, and 100 Hz and a 6-pulse, variable-frequency train with a mean frequency of 14.3 Hz were delivered at 1 train/s to induce fatigue. Immediately postfatigue, there was a significant effect of fatiguing protocol frequency. Muscles exhibited greater LFF after stimulation with the 9.1-, 14.3-, and variable-frequency trains. These three trains also produced the greatest mean force-time integrals during the fatigue test. At 2, ∼13, and ∼38 min of recovery, however, the LFF produced was independent of the fatiguing protocol frequency. The findings are consistent with theories suggesting two independent mechanisms behind LFF and may help identify the optimal activation pattern when functional electrical stimulation is used.

Effects of activation pattern on nonisometric human skeletal muscle performance

2007 ◽  
Vol 102 (5) ◽  
pp. 1985-1991 ◽  
Author(s):  
Ryan D. Maladen ◽  
Ramu Perumal ◽  
Anthony S. Wexler ◽  
Stuart A. Binder-Macleod
Keyword(s):  
Skeletal Muscle ◽  
Instantaneous Frequency ◽  
Muscle Activation ◽  
Motor Units ◽  
Muscle Performance ◽  
Variable Frequency ◽  
Constant Frequency ◽  
Muscle Activation Patterns ◽  
Activation Rate ◽  
Discharge Patterns

During volitional muscle activation, motor units often fire with varying discharge patterns that include brief, high-frequency bursts of activity. These variations in the activation rate allow the central nervous system to precisely control the forces produced by the muscle. The present study explores how varying the instantaneous frequency of stimulation pulses within a train affects nonisometric muscle performance. The peak excursion produced in response to each stimulation train was considered as the primary measure of muscle performance. The results showed that at each frequency tested between 10 and 50 Hz, variable-frequency trains that took advantage of the catchlike property of skeletal muscle produced greater excursions than constant-frequency trains. In addition, variable-frequency trains that could achieve targeted trajectories with fewer pulses than constant-frequency trains were identified. These findings suggest that similar to voluntary muscle activation patterns, varying the instantaneous frequency within a train of pulses can be used to improve muscle performance during functional electrical stimulation.

Catchlike-inducing train activation of human muscle during isotonic contractions: burst modulation

1999 ◽  
Vol 87 (5) ◽  
pp. 1758-1767 ◽  
Author(s):  
Samuel C. K. Lee ◽  
Cara N. Becker ◽  
Stuart A. Binder-Macleod
Keyword(s):  
Isometric Contraction ◽  
Peak Power ◽  
Average Power ◽  
Knee Extension ◽  
Human Muscle ◽  
Constant Frequency ◽  
Maximum Voluntary Isometric Contraction ◽  
Before And After ◽  
Isotonic Performance ◽  
Isotonic Contractions

Stimulation trains that exploit the catchlike property [catchlike-inducing trains (CITs)] produce greater forces and rates of rise of force than do constant-frequency trains (CFTs) during isometric contractions and isovelocity movements. This study examined the effect of CITs during isotonic contractions in healthy subjects. Knee extension was electrically elicited against a load of 10% of maximum voluntary isometric contraction. The stimulation intensity was set to produce 20% of maximum voluntary isometric contraction. The muscle was tested before and after fatigue with a 6-pulse CFT and 6-pulse CITs that contained an initial doublet, triplet, or quadruplet. For prefatigue responses, the greatest isotonic performance was produced by CITs with initial doublets. When the muscles were fatigued, triplet CITs were best. CITs produce greater excursion, work, peak power, and average power than do CFTs, because CITs produced more rapid rates of rise of force. Faster rates of rise of force enabled the preload on the muscle to be exceeded earlier during the stimulation train.

scholarly journals Upper and lower body coordination in FES-assisted sit-to-stand transfers in paraplegic subjects - A case study

2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Jovana Jović ◽  
Christine Azevedo Coste ◽  
Philippe Fraisse ◽  
Charles Fattal
Keyword(s):  
Electrical Stimulation ◽  
Detection Algorithm ◽  
The Body ◽  
Lower Body ◽  
Trunk Movement ◽  
Sit To Stand ◽  
Trunk Acceleration ◽  
The Subject ◽  
Stimulation Pattern

AbstractThe objective of the work presented is to improve functional electrical stimulation (FES) assisted sit-to-stand motion in complete paraplegic individuals by restoring coordination between the upper part of the subject’s body, under voluntary control, and the lower part of the body, under FES control. The proposed approach is based on the observation of trunk movement during rising motion and a detection algorithm, which triggers a pre-programmed stimulation pattern. We present a pilot study carried out on one T6 paraplegic subject. We validated the ability of the subject to produce repeatable trunk acceleration during sit-to-stand transfers under FES and, the ability of the system to trigger the stimulator at the desired instant in time. We also analyzed the influence of the timing of leg stimulation, relative to the trunk acceleration profile, on upper limb efforts applied during sit-to-stand motion.

Effects of Series Elasticity on the Human Knee Extension Torque-Angle Relationship in Vivo

2006 ◽  
Vol 77 (4) ◽  
pp. 408-416 ◽  
Author(s):  
Keitaro Kubo ◽  
Kazuya Ohgo ◽  
Ryuichi Takeishi ◽  
Kazunari Yoshinaga ◽  
Naoya Tsunoda ◽  
...  
Keyword(s):  
Knee Extension ◽  
Human Knee ◽  
Series Elasticity ◽  
Torque Angle

Effects of electrical stimulation pattern on quadriceps isometric force and fatigue in individuals with spinal cord injury

2015 ◽  
Vol 52 (2) ◽  
pp. 260-264 ◽  
Author(s):  
Gaelle Deley ◽  
Jeremy Denuziller ◽  
Nicolas Babault ◽  
John Andrew Taylor
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Electrical Stimulation ◽  
Isometric Force ◽  
Cord Injury ◽  
Stimulation Pattern

scholarly journals Fatigability and Variable-Frequency Train Stimulation of Human Skeletal Muscles

2003 ◽  
Vol 83 (4) ◽  
pp. 366-373 ◽  
Author(s):  
C Scott Bickel ◽  
Jill M Slade ◽  
Gordon L Warren ◽  
Gary A Dudley
Keyword(s):  
Rise Time ◽  
Physical Therapists ◽  
Fiber Type ◽  
Peak Torque ◽  
Variable Frequency ◽  
Constant Frequency ◽  
Time Integral ◽  
Type Composition ◽  
History Of ◽  
Frequency Train

Abstract Background and Purpose. The quadriceps femoris (QF) and tibialis anterior (TA) muscles are often activated through the use of electrical stimulation by physical therapists. These 2 muscles are fundamentally different in regard to their fiber-type composition. Whether protocols developed using a given muscle can be applied to another muscle has seldom been questioned, even if they differ in fiber type. The purpose of this study was to test the hypothesis that torque augmentation during variable-frequency train (VFT) stimulation as compared with constant-frequency train (CFT) stimulation in the fatigued state would not differ between these muscles, even though the TA muscle has 50% relatively more slow fibers than the QF muscle relative to each muscle's overall composition. Subjects. Ten recreationally active men with no history of lower-extremity pathology participated in the study (mean age=25 years, SD=4, range=19–31; mean height=179 cm, SD=5, range=170–188; mean body mass=80 kg, SD=15, range=63–111). Methods. The subjects' TA and QF muscles were stimulated with CFTs (six 200-microsecond square waves separated by 70 milliseconds) or VFTs (first interpulse interval=5 milliseconds) that evoked an isometric contraction. Results. After potentiation, the torque-time integral and peak torque were not different for the VFT and CFT stimulation. Rise time was longer for the TA muscle than for the QF muscle and for CFT stimulation versus VFT stimulation (both approximately 40%). After 180 CFTs (50% duty cycle), peak torque decreased 56% overall, with no differences between muscles. Enhancement of the torque-time integral (25%) by VFT stimulation was not different between fatigued QF and TA muscles. Torque augmentation was due to the VFT stimulation evoking 27% greater peak torque and less slowing of rise time than the CFT stimulation (15% versus 30%). Discussion and Conclusion. The results indicate that the QF muscle may not necessarily fatigue more than the TA muscle. The results suggest that VFTs augment the force of fatigued, human skeletal muscle irrespective of fiber type.

scholarly journals Validity and Test-Retest Reliability of a Novel Push Low-Cost Hand-Held Dynamometer for Knee Strength Assessment During Different Force Ranges

2021 ◽  
Author(s):  
Maria de Cássia Macedo ◽  
Matheus Almeida Souza ◽  
Kariny Realino Ferreira ◽  
Laura Oliveira Campos ◽  
Igora Sérgio Oliveira Souza ◽  
...  
Keyword(s):  
Isometric Force ◽  
Low Cost ◽  
Knee Extension ◽  
Isometric Strength ◽  
Retest Reliability ◽  
Strength Assessment ◽  
Knee Strength ◽  
Effective Form ◽  
Test Retest Reliability ◽  
User Friendly

The objective was to assess the instrumental validity and the test-retest reliability of a low-cost hand-held push dynamometer adapted from a load-cell based hanging scale (tHHD) to collect compressive forces in different ranges of compressive forces. Three independent raters applied 50 pre-established compressions each on the tHHD centered on a force platform in 3 distinct ranges: ~70 N, ~160 N, ~250 N. Knee isometric strength was also assessed on 19 subjects in two sessions (48h apart) using the tHHD anchored by an inelastic adjustable strap. Knee extension and flexion were assessed with the participant seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. The isometric force peaks were recorded and compared. The ICC and the Cronbach’s α showed excellent consistency and agreement for both instrumental validity and test-retest reliability, as the correlation and determination coefficients. The SEM and the MDC analysis returned adequate low values with a coefficient of variation less than 5%. The Bland-Altman results showed consistency and high levels of agreement. The tHHD is a valid method to assess the knee isometric strength, showing portability, cost-effectiveness, and user-friendly interface to provide an effective form to assess the knee isometric strength.

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