scholarly journals Effects of Fourteen-Day Bed Rest on Trunk Stabilizing Functions in Aging Adults

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Nejc Sarabon ◽  
Jernej Rosker
Keyword(s):  
Arm Movement ◽  
Bed Rest ◽  
Complete Recovery ◽  
Anticipatory Postural Adjustments ◽  
Trunk Muscles ◽  
Significant Deterioration ◽  
Response Latencies ◽  
Postural Adjustments ◽  
Postural Reflex ◽  
Aging Adults

Bed rest has been shown to have detrimental effects on structural and functional characteristics of the trunk muscles, possibly affecting trunk and spinal stability. This is especially important in populations such as aging adults with often altered trunk stabilizing functions. This study examined the effects of a fourteen-day bed rest on anticipatory postural adjustments and postural reflex responses of the abdominal wall and back muscles in sixteen adult men. Postural activation of trunk muscles was measured using voluntary quick arm movement and sudden arm loading paradigm. Measurements were conducted prior to the bed rest, immediately after, and fourteen days after the bed rest. Immediately after the bed rest, latencies of anticipatory postural adjustments showed significant shortening, especially for the obliquus internus and externus muscles. After a fourteen-day recuperation period, anticipatory postural adjustments reached a near to complete recovery. On the contrary, reactive response latencies increased from pre-bed-rest to both post-bed-rest measurement sessions. Results indicate an important effect of bed rest on stabilizing functions of the trunk muscles in elderly adults. Moreover, there proved to be a significant deterioration of postural reactive responses that outlasted the 14-day post-bed-rest rehabilitation.

Effect of age on anticipatory postural adjustments in unilateral arm movement

2006 ◽  
Vol 24 (2) ◽  
pp. 203-210 ◽  
Author(s):  
Séverine Bleuse ◽  
François Cassim ◽  
Jean-Louis Blatt ◽  
Etienne Labyt ◽  
Philippe Derambure ◽  
...  
Keyword(s):  
Arm Movement ◽  
Anticipatory Postural Adjustments ◽  
Postural Adjustments ◽  
Effect Of Age

scholarly journals A Novel Viewpoint on the Anticipatory Postural Adjustments During Gait Initiation

2021 ◽  
Vol 15 ◽  
Author(s):  
Veronica Farinelli ◽  
Francesco Bolzoni ◽  
Silvia Maria Marchese ◽  
Roberto Esposti ◽  
Paolo Cavallari
Keyword(s):  
Center Of Pressure ◽  
Force Plate ◽  
Anticipatory Postural Adjustments ◽  
The Body ◽  
Erector Spinae ◽  
Trunk Muscles ◽  
Gait Initiation ◽  
Concentrated Force ◽  
Postural Adjustments ◽  
Leg Muscles

Anticipatory postural adjustments (APAs) are the coordinated muscular activities that precede the voluntary movements to counteract the associated postural perturbations. Many studies about gait initiation call APAs those activities that precede the heel-off of the leading foot, thus taking heel-off as the onset of voluntary movement. In particular, leg muscles drive the center of pressure (CoP) both laterally, to shift the body weight over the trailing foot and backward, to create a disequilibrium torque pushing forward the center of mass (CoM). However, since subjects want to propel their body rather than lift their foot, the onset of gait should be the CoM displacement, which starts with the backward CoP shift. If so, the leg muscles driving such a shift are the prime movers. Moreover, since the disequilibrium torque is mechanically equivalent to a forward force acting at the pelvis level, APAs should be required to link the body segments to the pelvis: distributing such concentrated force throughout the body would make all segments move homogeneously. In the aim of testing this hypothesis, we analyzed gait initiation in 15 right-footed healthy subjects, searching for activities in trunk muscles that precede the onset of the backward CoP shift. Subjects stood on a force plate for about 10 s and then started walking at their natural speed. A minimum of 10 trials were collected. A force plate measured the CoP position while wireless probes recorded the electromyographic activities. Recordings ascertained that at gait onset APAs develop in trunk muscles. On the right side, Rectus Abdominis and Obliquus Abdominis were activated in 11 and 13 subjects, respectively, starting on average 33 and 54 ms before the CoP shift; Erector Spinae (ES) at L2 and T3 levels was instead inhibited (9 and 7 subjects, 104 and 120 ms). On the contralateral side, the same muscles showed excitatory APAs (abdominals in 11 and 12 subjects, 27 and 82 ms; ES in 10 and 7 subjects, 75 and 32 ms). The results of this study provide a novel framework for distinguishing postural from voluntary actions, which may be relevant for the diagnosis and rehabilitation of gait disorders.

scholarly journals EMG Analysis of Trunk Muscle Recruitment Patterns of Anticipatory Postural Adjustments during Unilateral Arm Flexion in Chronic Neck Pain Patients

2018 ◽  
Author(s):  
F Ghaffarinejad ◽  
A Kordi Yoosefinejad ◽  
S Pirouzi ◽  
A R Shakibafar ◽  
Z Bagheri ◽  
...  
Keyword(s):  
Neck Pain ◽  
Chronic Neck Pain ◽  
Anticipatory Postural Adjustments ◽  
Trunk Muscle ◽  
Trunk Muscles ◽  
Repeated Measure ◽  
Control Group ◽  
Onset Latency ◽  
Postural Adjustments ◽  
Recruitment Patterns

Introduction: EMG recruitment pattern of trunk muscles can change to compensate pain. One of these pattern alterations occurs in anticipatory postural adjustments (APAs) or feedforward activity of trunk muscles prior to arm movements. No study has determined the EMG pattern alterations of trunk muscle recruitments during the arm movement in patients with chronic neck pain (CNP). This study was examined the effect of CNP on EMG activities of trunk muscles for APAs during rapid arm flexion. Material and Methods: Sixteen patients with CNP for at least 3 months and sixteen healthy individuals matched in gender, age and weight were selected in this semi-experimental study. Surface EMG was utilized to evaluate 8 trunk muscles bilaterally and right anterior fibers of deltoid muscle during a unilateral rapid arm flexion. Anticipatory muscle activity was calculated by EMG onset latency of the trunk muscle from 100 ms before deltoid activity to 100 ms after it. Also, the values of root mean square (RMS) in 4 epochs around the onset of deltoid EMG were measured and compared. A two-tailed t-test and repeated-measure ANOVA were used for statistical analyses.Results: The onset latency of muscles in left and right side, except left erector spine muscle, in patients showed a significantly higher delay compared to healthy controls (P<0.05). The analysis of RMS in the 4 epochs revealed that in the control group, the values of RMS for rectus abdominus and erector spine in both sides, left external oblique and left transverse abdominus/internal oblique increased significantly during Epochs 3 and 4 , but in CNP subjects, the RMS of these muscles did not change significantly in 4 epochs.Conclusion: The patients with CNP had alterations in their recruitment patterns of particular trunk muscles in response to arm movement.Therefore, these patients have impaired motor control of trunk muscles during internal perturbation. These results indicated that not only the alterations in recruitment of trunk muscles occur, but also the intensity of their contractions decreases. In conclusion, CNP may alter in order to control the reactive forces resulting from limb movement. 

scholarly journals Two aspects of feedforward postural control: anticipatory postural adjustments and anticipatory synergy adjustments

2011 ◽  
Vol 105 (5) ◽  
pp. 2275-2288 ◽  
Author(s):  
Miriam Klous ◽  
Pavle Mikulic ◽  
Mark L. Latash
Keyword(s):  
Muscle Activation ◽  
Center Of Pressure ◽  
Anticipatory Postural Adjustments ◽  
Uncontrolled Manifold ◽  
Trunk Muscles ◽  
Body Sway ◽  
Postural Adjustments ◽  
Muscle Mode ◽  
Shoulder Flexion ◽  
Muscle Modes

We used the framework of the uncontrolled manifold hypothesis to explore the relations between anticipatory synergy adjustments (ASAs) and anticipatory postural adjustments (APAs) during feedforward control of vertical posture. ASAs represent a drop in the index of a multimuscle-mode synergy stabilizing the coordinate of the center of pressure in preparation to an action. ASAs reflect early changes of an index of covariation among variables reflecting muscle activation, whereas APAs reflect early changes in muscle activation levels averaged across trials. The assumed purpose of ASAs is to modify stability of performance variables, whereas the purpose of APAs is to change magnitudes of those variables. We hypothesized that ASAs would be seen before APAs and that this finding would be consistent with regard to the muscle-mode composition defined on the basis of different tasks and phases of action. Subjects performed a voluntary body sway task and a quick, bilateral shoulder flexion task under self-paced and reaction time conditions. Surface muscle activity of 12 leg and trunk muscles was analyzed to identify sets of 4 muscle modes for each task and for different phases within the shoulder flexion task. Variance components in the muscle-mode space and indexes of multimuscle-mode synergy stabilizing shift of the center of pressure were computed. ASAs were seen ∼100–150 ms prior to the task initiation, before APAs. The results were consistent with respect to different sets of muscle modes defined over the two tasks and different shoulder flexion phases. We conclude that the preparation for a self-triggered postural perturbation is associated with two types of anticipatory adjustments, ASAs and APAs. They reflect different feedforward processes within the hypothetical hierarchical control scheme, resulting in changes in patterns of covariation of elemental variables and in their patterns averaged across trials, respectively. The results show that synergies quantified using dissimilar sets of muscle modes show similar feedforward changes in preparation to action.

Individuals With Stroke Use Asymmetrical Anticipatory Postural Adjustments When Counteracting External Perturbations

Motor Control ◽  
2019 ◽  
Vol 23 (4) ◽  
pp. 461-471
Author(s):  
Etem Curuk ◽  
Yunju Lee ◽  
Alexander S. Aruin
Keyword(s):  
Muscle Activity ◽  
Balance Control ◽  
Anticipatory Postural Adjustments ◽  
Trunk Muscles ◽  
Electromyographic Activity ◽  
Healthy Controls ◽  
Unaffected Side ◽  
Postural Adjustments ◽  
External Perturbations ◽  
Anticipatory Activation

The authors investigated anticipatory postural adjustments in persons with unilateral stroke using external perturbations. Nine individuals with stroke and five control subjects participated. The electromyographic activity of 16 leg and trunk muscles was recorded. The onsets of muscle activity during the anticipatory phase of postural control were analyzed. The individuals with stroke did not show an anticipatory activation of leg and trunk muscles on the affected side; instead, the muscle onsets were seen after the perturbation, during the balance restoration phase. However, an anticipatory activation of muscles on the unaffected side was seen in individuals with stroke, and it was observed earlier compared with healthy controls (p < .05). The individuals with stroke showed a distal to proximal order of anticipatory activation of muscles on the unaffected side. The outcome of the study provides a basis for future investigations regarding ways of improving balance control in people with stroke.

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