The goal of this study was to determine if exposure to sensorimotor adaptation training improved head stabilization in older adults. Sixteen participants, age 66–81 yr, were assigned at random to the control group (n = 8) or the experimental group (n = 8). Both groups first completed 6 trials of walking a foam pathway consisting of a moveable platform that induced a lateral perturbation during walking. Head-in-space and trunk-in-space angular velocities were collected. Participants from both groups then trained twice per week for 4 wk. Both groups walked on a treadmill for 20 min. The control group viewed a static scene. The experimental group viewed a rotating visual scene that provided a perceptual-motor mismatch. After training, both groups were retested on the perturbation pathway test. The experimental group used a movement strategy that preserved head stabilization compared with the controls (p < .05). This training effect was not retained after 4 wk.
Regina R. Buccello-Stout, Ronita L. Cromwell, Jacob J. Bloomberg and Elbert B. Whorton
Rachael D. Seidler
Visuomotor adaptive processes were examined by testing transfer of adaptation between similar conditions. Participants made manual aiming movements with a joystick to hit targets on a computer screen, with real-time feedback display of their movement. They adapted to three different rotations of the display in a sequential fashion, with a return to baseline display conditions between rotations. Adaptation was better when participants had prior adaptive experiences. When performance was assessed using direction error (calculated at the time of peak velocity) and initial endpoint error (error before any overt corrective actions), transfer was greater when the final rotation reflected an addition of previously experienced rotations (adaptation order 30° rotation, 15°, 45°) than when it was a subtraction of previously experienced conditions (adaptation order 45° rotation, 15°, 30°). Transfer was equal regardless of adaptation order when performance was assessed with final endpoint error (error following any discrete, corrective actions). These results imply the existence of multiple independent processes in visuomotor adaptation.
Dennis A. Nowak, Joachim Hermsdörfer, Jens Philipp, Christian Marquardt, Stefan Glasauer and Norbert Mai
We investigated the quality of predictive grip force control during gravity changes induced by parabolic flight maneuvers. During these maneuvers gravity varied: There were 2 periods of hypergravity, in which terrestrial gravity nearly doubled, and a 20-s period of microgravity, during which a manipulated object was virtually weightless. We determined grip and load forces during vertical point-to-point movements of an instrumented object. Point-to-point movements were a combination of static (stationary holding) and dynamic (continuous movements) task conditions, which were separately analyzed in our previous studies. Analysis of the produced grip forces revealed that grip adjustments were closely linked to load force fluctuations under each gravity condition. In particular, grip force maxima coincided closely in time with load force peaks, although these occurred at different phases of the movement depending on the gravity level. However, quantitative analysis of the ratio of maximum grip force to the corresponding load force peak revealed an increased force ratio during microgravity when compared to that during normal and hypergravity, We hypothesize that the impaired precision of force coupling with respect to force magnitude during microgravity results from reduced feedback information about the object's mass during the stationary holding of the object in between each movement. The results indicate that the temporal grip force regulation is highly automatized and stable, whereas economical planning of force magnitude is more flexible and might reflect changes of the external loading condition.
Dalia Mickeviciene, Renata Rutkauskaite, Dovile Valanciene, Diana Karanauskiene, Marius Brazaitis and Albertas Skurvydas
sensorimotor adaptation, which is fast learning ( Anguera, Reuter-Lorenz, Willingham, & Seidler, 2011 ). These changes occur gradually over the course of 100–200 repetitions. Although decreases or increases in these parameters have been documented in a variety of tasks ( Shadmehr et al., 2010 ; Wolpert et
Peiyuan Wang, Frank J. Infurna and Sydney Y. Schaefer
evidenced by several types of motor learning paradigms, including sensorimotor adaptation ( McNay & Willingham, 1998 ; Seidler, 2006 ), complex motor skill acquisition ( Brown, Robertson, & Press, 2009 ; Pratt, Chasteen, & Abrams, 1994 ), and motor sequence learning ( Ehsani, Abdollahi, Mohseni Bandpei
John Andrew Badagliacco and Andrew Karduna
injuries is not completely understood, there are many distinct physical characteristics of the throwing shoulder that have been studied in relation to injury, such as range of motion (ROM), laxity, osseous adaptations, muscle strength, and scapular position. 6 However, less is known about the sensorimotor
Yuko Kuramatsu, Yuji Yamamoto and Shin-Ichi Izumi
direction that is inherently unstable for them. We investigated dynamic balance control in poststroke individuals with hemiparesis executing whole-body movements to try to understand the sensorimotor adaptations that may have developed. STS is a mechanically demanding, daily, whole-body activity ( Carr
Erik A. Wikstrom and Patrick O. McKeon
of ≥1 significant lateral ankle sprain, “giving way” episodes, sustaining recurrent sprains, and/or having “feelings of instability”. 5 The condition is also associated with structural and/or sensorimotor adaptations, 6 decreased quality of life scores, 7 lower observed levels of physical activity
Arturo Forner-Cordero, Virgínia H. Quadrado, Sitsofe A. Tsagbey and Bouwien C.M. Smits-Engelsman
primary dystonia . Journal of NeuroEngineering and Rehabilitation, 9 , 46 . PubMed doi:10.1186/1743-0003-9-46 10.1186/1743-0003-9-46 Caselli , P. , Conforto , S. , Schmid , M. , Accornero , N. , & D’Alessio , T. ( 2006 ). Difference in sensorimotor adaptation to horizontal and vertical
Lena Hübner, Solveig Vieluf, Ben Godde and Claudia Voelcker-Rehage
, M. ( 2006 ). Relationship between sensorimotor adaptation and cognitive functions in younger and older subjects . Experimental Brain Research, 169 ( 3 ), 400 – 406 . PubMed ID: 16328306 doi:10.1007/s00221-005-0153-4. 10.1007/s00221-005-0153-4 Boe , S.G. , Cassidy , R.J. , McIlroy , W