1
|
Cherni Y, Girardin-Vignola G, Ballaz L, Begon M. Reliability of maximum isometric hip and knee torque measurements in children with cerebral palsy using a paediatric exoskeleton – Lokomat. Neurophysiol Clin 2019; 49:335-342. [DOI: 10.1016/j.neucli.2018.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/28/2018] [Accepted: 12/03/2018] [Indexed: 01/01/2023] Open
|
2
|
Abstract
The organization and functional logic of corticospinal motor neurons and their target connections remains unclear, despite their evident influence on movement. Spinal interneurons mediate much of this influence, yet we know little about the way in which corticospinal neurons engage spinal interneurons. This is perhaps not surprising given that the principles of organization of local spinal microcircuits remain elusive--we have glimpses of an underlying order but lack a comprehensive view of their functional architecture. In this brief essay we make a case that a new focus on the intersection of cortical and spinal circuits may provide clarity to the interpretation of corticospinal motor neuron firing patterns and help specify the logic of corticospinal motor neuronal function.
Collapse
Affiliation(s)
- Andrew Miri
- Departments of Neuroscience and Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute, Zuckerman Mind Brain Behavior Institute, and Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA.
| | | | | |
Collapse
|
3
|
Hedayatpour N, Arendt-Nielsen L, Falla D. Facilitation of quadriceps activation is impaired following eccentric exercise. Scand J Med Sci Sports 2012; 24:355-62. [DOI: 10.1111/j.1600-0838.2012.01512.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2012] [Indexed: 11/29/2022]
Affiliation(s)
- N. Hedayatpour
- Department of Physical Education and Sport Science; University of Bojnord; Bojnord Iran
- Department of Health Science and Technology; Center for Sensory-Motor Interaction (SMI); Aalborg University; Aalborg Denmark
| | - L. Arendt-Nielsen
- Department of Health Science and Technology; Center for Sensory-Motor Interaction (SMI); Aalborg University; Aalborg Denmark
| | - D. Falla
- Pain Clinic; Center for Anesthesiology; Emergency and Intensive Care Medicine; University Hospital Göttingen; Göttingen Germany
- Department of Neurorehabilitation Engineering; Bernstein Focus Neurotechnology (BFNT) Göttingen; Bernstein Center for Computational Neuroscience; University Medical Center Göttingen; Georg-August University; Göttingen Germany
| |
Collapse
|
4
|
|
5
|
|
6
|
|
7
|
|
8
|
|
9
|
Strategies for the control of studies of voluntary movements with one mechanical degree of freedom. Behav Brain Sci 2010. [DOI: 10.1017/s0140525x00048433] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
10
|
|
11
|
|
12
|
|
13
|
Abstract
AbstractA theory is presented to explain how accurate, single-joint movements are controlled. The theory applies to movements across different distances, with different inertial loads, toward targets of different widths over a wide range of experimentally manipulated velocities. The theory is based on three propositions. (1) Movements are planned according to “strategies” of which there are at least two: a speed-insensitive (SI) and a speed-sensitive (SS) one. (2) These strategies can be equated with sets of rules for performing diverse movement tasks. The choice between SI and SS depends on whether movement speed and/or movement time (and hence appropriate muscle forces) must be constrained to meet task requirements. (3) The electromyogram can be interpreted as a low-pass filtered version of the controlling signal to the motoneuron pools. This controlling signal can be modelled as a rectangular excitation pulse in which modulation occurs in either pulse amplitude or pulse width. Movements to different distances and with loads are controlled by the SI strategy, which modulates pulse width. Movements in which speed must be explicitly regulated are controlled by the SS strategy, which modulates pulse amplitude. The distinction between the two movement strategies reconciles many apparent conflicts in the motor control literature.
Collapse
|
14
|
|
15
|
|
16
|
|
17
|
|
18
|
|
19
|
|
20
|
|
21
|
Williams GN, Krishnan C. Response. Med Sci Sports Exerc 2010. [DOI: 10.1249/mss.0b013e3181c225ac] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
22
|
MacKenzie SJ, Rannelli LA, Yurchevich JJ. Neuromuscular Adaptations Following Antagonist Resisted Training. J Strength Cond Res 2010; 24:156-64. [DOI: 10.1519/jsc.0b013e3181bd4317] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
23
|
Bazzucchi I, Riccio ME, Felici F. Tennis players show a lower coactivation of the elbow antagonist muscles during isokinetic exercises. J Electromyogr Kinesiol 2008; 18:752-9. [PMID: 17449279 DOI: 10.1016/j.jelekin.2007.03.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 03/06/2007] [Accepted: 03/06/2007] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Previous studies have suggested that muscle coactivation could be reduced by a recurrent activity (training, daily activities). If this was correct, skilled athletes should show a specific muscle activation pattern with a low level of coactivation of muscles which are typically involved in their discipline. In particular, the aim of this study was to verify the hypothesis that the amount of antagonist activation of biceps brachii (BB) and triceps brachii (TB) is different between tennis players and non-players individuals during maximal isokinetic contractions. METHODS Ten young healthy men and eight male tennis players participated in the study. The surface electromyographic signals (sEMG) were recorded from the BB and TB muscles during three maximal voluntary isometric contractions (MVC) of elbow flexors and extensors and a set of three maximal elbow flexions and extensions at 15 degrees , 30 degrees , 60 degrees , 120 degrees , 180 degrees and 240 degrees /s. Normalized root mean square (RMS) of sEMG was calculated as an index of sEMG amplitude. RESULTS Antagonist activation (%RMSmax) of TB was significantly lower in tennis players (from 14.0+/-7.9% at MVC to 16.3+/-8.9% at 240 degrees /s) with respect to non-players (from 27.7+/-19.7% at MVC to 38.7+/-17.6% at 240 degrees /s) at all angular velocities. Contrary to non-players, tennis players did not show any difference in antagonist activation between BB and TB muscles. CONCLUSIONS Tennis players, with a constant practice in controlling forces around the elbow joint, learn how to reduce coactivation of muscles involved in the control of this joint. This has been shown by the lower antagonist muscular activity of triceps brachii muscle during isokinetic elbow flexion found in tennis players with respect to non-players.
Collapse
Affiliation(s)
- Ilenia Bazzucchi
- Department of Human Movement, Istituto Universitario di Scienze Motorie, Piazza Lauro De Bosis 6, Roma 00194, Italy.
| | | | | |
Collapse
|
24
|
de Boer MD, Morse CI, Thom JM, de Haan A, Narici MV. Changes in Antagonist Muscles' Coactivation in Response to Strength Training in Older Women. J Gerontol A Biol Sci Med Sci 2007; 62:1022-7. [PMID: 17895442 DOI: 10.1093/gerona/62.9.1022] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The purpose of this study was to assess changes in neuromuscular function of the plantarflexor and dorsiflexor muscles after 1 year of strength training of these muscles in elderly women. Twelve participants were assigned to a training (74.2 +/- 3.1 years) group and eight to a nontraining group (73.6 +/- 4.3 years). METHODS Isometric maximum voluntary contractions (MVC) and muscle activation based on surface electromyography (EMG) were recorded before and after the 12-month training program at six different joint angles. RESULTS After training (in the training group), (a) plantarflexion (PF) MVC increased on average by 14.4% (p <.05) across ankle joint angles from -20 degrees dorsiflexion (DF) to +30 degrees PF, (b) DF MVC decreased by 5.7% (p <.05), (c) PF EMG root mean square increased on average by 22.3% (p <.05), and (d) PF antagonists' coactivation increased on average by 7.5% across the tested joint angles. No changes were observed in the nontraining group. CONCLUSIONS The present results show a significant increase in antagonist muscle coactivation with strength training in older women. The hypothesis is put forward that with a training-induced gain in agonist muscles' torque, stabilization of the ankle joint by increasing antagonist coactivation is needed because of a changed ratio of maximal PF torque to maximal DF torque.
Collapse
Affiliation(s)
- Maarten D de Boer
- Institute for Biophysical and Clinical Research into Human Movement, Manchester Metropolitan University, Alsager, ST7 2HL, United Kingdom
| | | | | | | | | |
Collapse
|
25
|
Moore SP, Marteniuk RG. Kinematic and electromyographic changes that occur as a function of learning a time-constrained aiming task. J Mot Behav 2005; 18:397-426. [PMID: 15138139 DOI: 10.1080/00222895.1986.10735388] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The present study attempted to examine the changes associated with learning two time-constrained aiming movements at the neuromuscular and behavioral levels of analysis. Electromyographic data and movement kinematics were used to assess changes due to practice. Eight right-handed females were required to perform a 45 degrees horizontal forearm extension in either 200 ms or 500 ms for 100 trials on each of four consecutive days. Both groups demonstrated an improvement in performance and a decrease in within-subject variability in the endpoint response measures, movement trajectory, and myoelectric pattern. With practice, there was a decrease in the amount of cocontraction between the agonist and antagonist muscles during movement execution, which indicated an elimination of unwanted neural activity. For the 200 ms task, the acceleration profile became symmetrical and triphasic myoelectric pattern became evident. The deceleratory phase of the 500 ms task was longer than the acceleratory phase, and a biphasic pattern became apparent. The results suggest that two different control strategies were developed in the execution of the two movements examined. In addition, the relative invariance of the spatial-temporal dependent measures, as compared to the variability of the EMG, led us tot he conclusion that the movement planning hierarchy was concerned with the spatial-temporal domain, whereas the amplitude and timing of muscular activity were planned at a lower level and thus played a subordinate role in movement production.
Collapse
Affiliation(s)
- S P Moore
- Department of Kinesiology, University of Waterloo, Ontario, Canada
| | | |
Collapse
|
26
|
Buckon CE, Thomas SS, Harris GE, Piatt JH, Aiona MD, Sussman MD. Objective measurement of muscle strength in children with spastic diplegia after selective dorsal rhizotomy. Arch Phys Med Rehabil 2002; 83:454-60. [PMID: 11932845 DOI: 10.1053/apmr.2002.31202] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To examine changes in isometric muscle strength at the elbow, knee, and ankle at 6 months and 1 year after selective dorsal rhizotomy (SDR) and to determine if SDR altered the frequency of muscle cocontraction. DESIGN Prospective outcome study of a consecutive sample. SETTING Children's hospital. PATIENTS Ten children with spastic diplegia (7 independent and 3 dependent ambulators who used assistive devices) and 8 age-matched controls. INTERVENTIONS SDR; physical and occupational therapy; elbow, knee, and ankle measured for flexion and extension strength during three 10-second isometric contractions for each muscle group; and monitored cocontraction measured via muscle electrodes. MAIN OUTCOME MEASURES Absolute and normalized values of isometric strength; and alterations in the frequency of cocontraction at 6 months and 1 year postoperatively. RESULTS Children with spastic diplegia showed significantly weaker knee extensors, ankle dorsiflexors, and ankle plantarflexors than age-matched controls. There were no significant differences in strength between the 2 groups in the elbow flexors, elbow extensors, and knee flexors. Isometric strength did not increase or decrease significantly after SDR. Cocontraction during knee extension was normalized after SDR, whereas cocontraction during ankle plantarflexion was unchanged by SDR in the majority of children. CONCLUSION SDR did not result in a significant decrease in muscle strength in ambulatory children with spastic diplegia. The normalization of the electromyographic patterns at the knee and not the ankle after SDR lends support to the premise that in children with cerebral palsy cocontraction is multifaceted, representing a volitional strategy to enhance control, as well as a disorder of the mechanisms that govern patterns of muscle activity.
Collapse
Affiliation(s)
- Cathleen E Buckon
- Clinical Research Department, Shriners Hospital for Children, 3101 SW Sam Jackson Park Rd., Portland, OR 97201, USA.
| | | | | | | | | | | |
Collapse
|
27
|
Levin MF. Sensorimotor deficits in patients with central nervous system lesions: Explanations based on the λ model of motor control. Hum Mov Sci 2000. [DOI: 10.1016/s0167-9457(00)00004-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
28
|
Kellis E. The effects of fatigue on the resultant joint moment, agonist and antagonist electromyographic activity at different angles during dynamic knee extension efforts. J Electromyogr Kinesiol 1999; 9:191-9. [PMID: 10328414 DOI: 10.1016/s1050-6411(98)00032-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Examination of the effects of fatigue on antagonist function can provide information on the role of antagonists in limiting the resultant joint moment and stabilizing the knee. Therefore, the purpose of this study was to examine the moment, agonist and antagonist electromyographic (EMG) activity levels at different angular positions during an isokinetic muscular endurance knee extension test. Fifteen healthy males (age 22.6+/-1.9 yr) performed 34 maximal isokinetic concentric efforts of the knee extensors at 120 degrees s(-1). The EMG activity of vastus medialis and biceps femoris was recorded using surface electrodes. The motion ranged from 90 degrees to 0 degrees of knee flexion. The average moment and average EMG (AEMG) at 10-35 degrees, 36-55 degrees and 56-80 degrees angular position intervals were calculated for each repetition. Twenty eight efforts were further analysed. The moment of force demonstrated a decline of 70% at the end of the test. Two-way repeated measures analysis of variance tests indicated that this decline was significant (p < 0.05). No significant effects of angular position on fatigue moment characteristics were found. The agonist (vastus medialis) AEMG during the first repetition demonstrated a significant increase of 40-60% towards the middle part of the test (p < 0.05). In the second part of the test, the VM AEMG at longer muscle lengths was significantly higher compared to the initial efforts whereas the AEMG at short muscle lengths returned to initial values. The antagonist AEMG at all angular positions did not change significantly during the test. The decline in the resultant joint moment could be attributed to the effects of fatigue on the agonist muscle function. The agonist AEMG fatigue-patterns are dependent on the length of the muscle and may be due to alterations in the motor unit recruitment and/or activation failure in the quadriceps muscle. The biceps femoris maintains constant submaximal (21-33% of the maximum) AEMG activity which may play an important role in the stability of the knee joint. The contribution of antagonist activity to the resultant joint moment increases during the last part of an isokinetic concentric muscle endurance test.
Collapse
Affiliation(s)
- E Kellis
- Sport Performance Research Group, Division of Sport Sciences, University of Northumbria at Newcastle, Newcastle upon Tyne, UK
| |
Collapse
|
29
|
Kellis E, Baltzopoulos V. Muscle activation differences between eccentric and concentric isokinetic exercise. Med Sci Sports Exerc 1998; 30:1616-23. [PMID: 9813875 DOI: 10.1097/00005768-199811000-00010] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this study was to compare electromyographic (EMG) activity and joint moment of agonists and antagonists between isokinetic eccentric and concentric knee muscle actions. METHODS Twelve females (20.5 +/- 2.9 yr) performed maximum knee extension and flexion effort on a Biodex dynamometer isometrically and at concentric and eccentric angular velocities ranging from 30 degrees.s-1 to 150 degrees.s-1. EMG activity of vastus lateralis, rectus femoris, vastus medialis, and hamstrings was also recorded. The moment and agonist EMG values were normalized as a percentage of the maximum isometric values. The antagonist EMG was normalized as a percentage of the IEMG activity of the same muscle group when acting as agonist at the same angular velocity and angular position and taking into consideration the effects of muscle action. RESULTS Three-way ANOVA designs indicated significantly greater normalized eccentric moments compared with concentric moments (P < 0.05), whereas the eccentric normalized integrated EMG (IEMG) of agonists and antagonists was significantly lower compared with the respective concentric IEMG values (P < 0.05). These differences were more evident at fast angular velocities. CONCLUSIONS The present results demonstrate that neural activation and the resulting muscular action are different between isokinetic eccentric and concentric tests and depend also on the angular velocity of the movement. The antagonist IEMG activity is different depending on the muscle examined. The IEMG activity of the antagonists in this study indicate that the antagonist activity is an important factor that affects the resultant joint moment during isolated isokinetic maximum voluntary joint movements.
Collapse
Affiliation(s)
- E Kellis
- Division of Sport Science, University of Northumbria, Newcastle upon Tyne, United Kingdom
| | | |
Collapse
|
30
|
Kellis E, Baltzopoulos V. The effects of normalization method on antagonistic activity patterns during eccentric and concentric isokinetic knee extension and flexion. J Electromyogr Kinesiol 1996; 6:235-45. [DOI: 10.1016/s1050-6411(96)00012-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/1995] [Revised: 02/27/1996] [Accepted: 03/06/1996] [Indexed: 10/18/2022] Open
|
31
|
Rothmuller C, Cafarelli E. Effect of vibration on antagonist muscle coactivation during progressive fatigue in humans. J Physiol 1995; 485 ( Pt 3):857-64. [PMID: 7562623 PMCID: PMC1158050 DOI: 10.1113/jphysiol.1995.sp020775] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
1. Biceps femoris antagonist coactivation increases during progressive fatigue. Our purpose was to determine if the mechanism that increases coactivation during fatigue is susceptible to vibration. Vibration drives alpha-motoneurons via the Ia loop, producing force without descending motor drive, and thus uncoupling antagonist and agonist activation. Evidence that vibration increases coactivation disproportionately from its 'common drive' would suggest the possibility that some of the effects of fatigue are mediated through a segmental reflex loop. 2. Ten male subjects performed repeated maximal voluntary isometric contractions (MVCs) of the knee extensors of one leg. Paired submaximal test contractions (50% of MVC), without visual feedback, were performed when MVC reached 85, 70 and then 50% of its initial value. Vibration was applied to the patellar tendon during one test contraction in each pair. 3. Vibration reduced test contraction force below control values. However, coactivation increased at the same rate in both conditions. Biceps femoris coactivation was greater during vibration, but did not change during fatigue in either condition. 4. Our observations suggest that agonist-antagonist muscle pairs are controlled as a single motor unit pool by a common central drive. Vibrating the agonist increases antagonist coactivity, but does not alter the rate at which coactivation increases during fatigue. This supports the idea that agonist coactivation is controlled by a central mechanism.
Collapse
Affiliation(s)
- C Rothmuller
- Department of Physical Education, Faculty of Pure and Applied Science, York University, Toronto, Ontario, Canada
| | | |
Collapse
|
32
|
Weir JP, Housh TJ, Weir LL, Johnson GO. Effects of unilateral isometric strength training on joint angle specificity and cross-training. EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY AND OCCUPATIONAL PHYSIOLOGY 1995; 70:337-43. [PMID: 7649145 DOI: 10.1007/bf00865031] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The purpose of this study was to examine the effects of unilateral isometric leg extension strength training on the strength and integrated electromyogram (IEMG) of both the trained and untrained limbs at multiple joint angles. A training (TRN) group [nine women; mean (SD) age, 20(1) years] exercised for 6 weeks with isometric leg extensions at 80% of maximal isometric torque. A control (CTL) group [eight women; 21(1) years] did not exercise. The training was performed three times per week on a Cybex II isokinetic dynamometer at a joint angle where the lever arm was 0.79 rad below the horizontal plane. The subjects were tested pre- and posttraining for maximal unilateral isometric torque in both limbs at joint angles of zero, 0.26, 0.79, 1.31, and 1.57 rad below the horizontal plane. Bipolar surface electrodes were used to record the IEMG of the vastus lateralis (VL) and vastus medialis (VM) during the isometric tests. Three univariate (torque, IEMG-VL, and IEMG-VM) four-way (group x time x limb x angle) mixed factorial ANOVAs were used to analyze the data. The results indicated joint angle specificity for isometric torque in the TRN group only, with significant increases in torque at 0.79 (P = 0.0004) and 1.31 (P = 0.0039) rad. No significant increases in torque were found in the untrained limb of the TRN group or in either limb of the CTL group. Similarly, there were no significant changes in IEMG as a result of the training for the VL or VM.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- J P Weir
- Department of Movement Sciences and Education, Teachers College, Columbia University, New York, NY 10027, USA
| | | | | | | |
Collapse
|
33
|
Yamazaki Y, Ohkuwa T, Itoh H, Suzuki M. Reciprocal activation and coactivation in antagonistic muscles during rapid goal-directed movements. Brain Res Bull 1994; 34:587-93. [PMID: 7922602 DOI: 10.1016/0361-9230(94)90144-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Seven normal subjects performed elbow extensions as rapidly as possible from an initial position to a visually defined target at 36 degrees in amplitude. In electromyograms, the reciprocal activation of the agonist and then antagonist bursts was always followed by simultaneous activation of the antagonistic muscles, i.e., coactivation. Instructions added to perform extensions "as rapidly as possible" changed coactivation; the command to "strongly fix the upper arm at the target" increased coactivation, whereas "relax immediately after the start of movement" made coactivation almost disappear. However, basic features of reciprocal activation remained the same. Other instructions given also changed coactivation on initiation and termination, while reciprocal activation was relatively unaltered. When subjects were encouraged to "relax immediately after the start of movement, but fix the upper arm quickly after attaining the target," coactivation initiated shortly after reaching the target (< 200 ms). Following the instruction to "relax the upper arm quickly after attaining the target," coactivation terminated rapidly after reaching the target (< 280 ms). The results show that instructions serve to change amplitude and timing of coactivation while keeping reciprocal activation relatively unaltered, suggesting that coactivation is controlled independently of reciprocal activation during rapid goal-directed movements.
Collapse
Affiliation(s)
- Y Yamazaki
- Department of Health and Physical Education, Nagoya Institute of Technology, Japan
| | | | | | | |
Collapse
|
34
|
Degrees of freedom, dynamical laws, and boundary conditions for discrete voluntary movement. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
35
|
The strategy used to increase the amplitude of the movement varies with the muscle studied. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
36
|
Two ways to reduce motor programming load. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x0004838x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
37
|
At least two strategies. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
38
|
Elementary conditions for elemental movement strategies. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
39
|
Strategies and motor programs. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
40
|
Experiment and reality. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
41
|
Task variables and the saturation of the excitation pulse. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
42
|
Pulses, bursts, and single-joint movements. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
43
|
What is adapted in strategy-governed movements? Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
44
|
Bursts of discharge recorded from the red nucleus may provide real measures of Gottlieb's excitation pulses. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048391] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
45
|
On to real-life movements. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
46
|
Strategies for single-joint movements should also work for multijoint movements. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x0004841x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
47
|
Strategies are a means to an end. Behav Brain Sci 1989. [DOI: 10.1017/s0140525x00048317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
48
|
|
49
|
Abstract
Kinematic and myoelectric variables associated with rapid elbow-flexion movements of various distances to targets of various widths were studied. The movement time in these experiments conformed to Fitts' law: movement time increased with target distance and decreased with target width. Peak movement velocity, electromyograph (EMG) duration, and EMG quantity were poorly described by Fitts' law, for increases in target width were accompanied by increases in these variables. We show with regression equations, using separate weighting coefficients, that kinematic and myoelectric variables can be related to distance and target width. The use of distance and target width as independent variables allows us to suggest that the literature does not agree on the relation between EMG and distance moved partly because of the influences of the target on this relationship. We propose that human voluntary movement involves a subject "strategy," or set of internal constraints, that affect movement outcome. Significant elements of this strategy, such as how accurately to perform the task, may not be recognized or controlled in many movement paradigms, in spite of uniform instruction to subjects and similar apparatus.
Collapse
Affiliation(s)
- D M Corcos
- University of Illinois at Chicago, Department of Physical Education, USA
| | | | | |
Collapse
|
50
|
Basmajian JV. Electromyography--dynamic gross anatomy: a review. THE AMERICAN JOURNAL OF ANATOMY 1980; 159:245-60. [PMID: 7010981 DOI: 10.1002/aja.1001590302] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|