scholarly journals EXPRESS: Getting a Handle on Sales: Shopping Carts Affect Purchasing by Activating Arm Muscles

2021 ◽  
pp. 002224292110613
Author(s):  
Zachary Estes ◽  
Mathias C. Streicher
Keyword(s):  
Field Experiment ◽  
Physical Properties ◽  
Muscle Activation ◽  
Upper Arm ◽  
Shopping Cart ◽  
Extensor Muscles ◽  
Flexor Muscles ◽  
Arm Muscles

This research demonstrates that the physical properties of shopping carts influence purchasing and spending. Prior research on ergonomics indicates that standard shopping carts, which are pushed via a horizontal handlebar, are likely to activate arm extensor muscles. Prior research on arm muscle activation, in turn, suggests that arm extensor activation may elicit less purchasing than arm flexor activation. The authors thus deduce that standard shopping carts may be suboptimal for stimulating purchases. The authors predicted that shopping carts with parallel handles (i.e., like a wheelbarrow or “walker”) would instead activate the flexor muscles and thus increase purchasing. An electromyography (EMG) study revealed that both horizontal and vertical handles more strongly activate the extensor muscles of the upper arm (triceps), whereas parallel handles more strongly activate the flexor muscles (biceps). In a field experiment, parallel-handle shopping carts significantly and substantially increased sales across a broad range of categories, including both vice and virtue products. Finally, in a simulated shopping experiment, parallel handles increased purchasing and spending beyond both horizontal and vertical handles. These results were not attributable to the novelty of the shopping cart itself, participants’ mood, or purely ergonomic factors.

Plasticity in the Distribution of the Red Nucleus Output to Forearm Muscles After Unilateral Lesions of the Pyramidal Tract

2000 ◽  
Vol 83 (5) ◽  
pp. 3147-3153 ◽  
Author(s):  
Abderraouf Belhaj-Saïf ◽  
Paul D. Cheney
Keyword(s):  
Pyramidal Tract ◽  
Red Nucleus ◽  
Emg Activity ◽  
Motor Impairments ◽  
Forearm Muscles ◽  
Extensor Muscles ◽  
Flexor Muscles ◽  
Lesion Method ◽  
Stimulus Triggered Averaging ◽  
Suppression Effects

It has been hypothesized that the magnocellular red nucleus (RNm) contributes to compensation for motor impairments associated with lesions of the pyramidal tract. To test this hypothesis, we used stimulus triggered averaging (StTA) of electromyographic (EMG) activity to characterize changes in motor output from the red nucleus after lesions of the pyramidal tract. Three monkeys were trained to perform a reach and prehension task. EMG activity was recorded from 11 forearm muscles including one elbow, five wrist, and five digit muscles. Microstimulation (20 μA at 20 Hz) was delivered throughout the movement task to compute StTAs. Two monkeys served as controls. In a third monkey, 65% of the left pyramidal tract had been destroyed by an electrolytic lesion method five years before recording. The results demonstrate a clear pattern of postlesion reorganization in red nucleus–mediated output effects on forearm muscles. The normally prominent extensor preference in excitatory output from the RNm (92% in extensors) was greatly diminished in the lesioned monkey (59%). Similarly, suppression effects, which are normally much more prominent in flexor than in extensor muscles (90% in flexors), were also more evenly distributed after recovery from pyramidal tract lesions. Because of the limited excitatory output from the RNm to flexor muscles that normally exists, loss of corticospinal output would leave control of flexors particularly weak. The changes in RNm organization reported in this study would help restore function to flexor muscles. These results support the hypothesis that the RNm is capable of reorganization that contributes to the recovery of forelimb motor function after pyramidal tract lesions.

scholarly journals Development of Postural Muscles and Their Innervation

2005 ◽  
Vol 12 (2-3) ◽  
pp. 141-151 ◽  
Author(s):  
J. IJkema-Paassen ◽  
A. Gramsbergen
Keyword(s):  
Motor Performance ◽  
Muscle Fibers ◽  
Animal Experiments ◽  
Great Resistance ◽  
Fiber Properties ◽  
Flexor Muscles ◽  
Dendrite Bundles ◽  
Arm Muscles ◽  
Muscle Actions ◽  
Postural Muscles

Control of posture is a prerequisite for efficient motor performance. Posture depends on muscles capable of enduring contractions, whereas movements often require quick, forceful muscle actions. To serve these different goals, muscles contain fibers that meet these different tasks. Muscles with strong postural functions mainly consist of slow muscle fibers with a great resistance against fatigue. Flexor muscles in the leg and arm muscles are mainly composed of fast muscle fibers producing relatively large forces that are rapidly fatigable. Development of the neuromuscular system continues after birth. We discuss in the human baby and in animal experiments changes in muscle fiber properties, regression from polyneural into mononeural innervation, and developmental changes in the motoneurons of postural muscles during that period. The regression of poly-neural innervation in postural muscles and the development of dendrite bundles of their motoneurons seem to be linked to the transition from the immature into the adult-like patterns of moving and postural control.

Older Adults Use a Unique Strategy to Lift Inertial Loads With the Elbow Flexor Muscles

2000 ◽  
Vol 83 (4) ◽  
pp. 2030-2039 ◽  
Author(s):  
Andrew E. Graves ◽  
Kurt W. Kornatz ◽  
Roger M. Enoka
Keyword(s):  
Young Adults ◽  
Elbow Joint ◽  
Muscle Activation ◽  
Angular Displacement ◽  
Elbow Flexor ◽  
Lengthening Contractions ◽  
Old Adults ◽  
Flexor Muscles ◽  
Elbow Flexor Muscles ◽  
Target Force

The purpose of this study was to determine the effect of age on the ability to exert steady forces and to perform steady flexion movements with the muscles that cross the elbow joint. An isometric task required subjects to exert a steady force to match a target force that was displayed on a monitor. An anisometric task required subjects to raise and lower inertial loads so that the angular displacement around the elbow joint matched a template displayed on a monitor. Steadiness was measured as the coefficient of variation of force and as the normalized standard deviation of wrist acceleration. For the isometric task, steadiness as a function of target force decreased similarly for old adults and young adults. For the anisometric task, steadiness increased as a function of the inertial load and there were significant differences caused by age. Old adults were less steady than young adults during both shortening and lengthening contractions with the lightest loads. Furthermore, old adults were least steady when performing lengthening contractions. These behaviors appear to be associated with the patterns of muscle activation. These results suggest that different neural strategies are used to control isometric and anisometric contractions performed with the elbow flexor muscles and that these strategies do not change in parallel with advancing age.

scholarly journals Hindlimb muscular activity, kinetics and kinematics of cats jumping to their maximum achievable heights

1981 ◽  
Vol 91 (1) ◽  
pp. 73-86 ◽  
Author(s):  
F. E. Zajac ◽  
M. R. Zomlefer ◽  
W. S. Levine
Keyword(s):  
Vertical Jump ◽  
Muscular Activity ◽  
Dynamic State ◽  
Extensor Muscles ◽  
Ankle Joints ◽  
Flexor Muscles ◽  
Reaction Forces ◽  
Vertical Ground ◽  
Vertical Ground Reaction Forces ◽  
Propulsion Phase

Cats were trained to jump from a force platform to their maximum achievable heights. Vertical ground reaction forces developed by individual hindlimbs showed that the propulsion phase consists of two epochs. During the initial “preparatory phase' the cat can traverse many different paths. Irrespective of the path traversed, however, the cat always attains the same position, velocity and momentum at the end of this phase. Starting from this dynamic state the cat during the subsequent “launching phase' (about 150 ms long) generates significant propulsion as its hindlimbs develop force with identical, stereotypic profiles. Cinematographic data, electromyographic data, and computed torques about the hip, knee and ankle joints indicate that during the jump proximal extensor musculature is activated before distal musculature. During terminal experiments when the hindlimb was set at positions corresponding to those in the jump, isometric torques produced by tetanic stimulation of groups of extensor and flexor muscles were compared with computed torques developed by the same cat during previous jumps. These comparisons suggest that extensor muscles of the hindlimb are fully activated during the maximal vertical jump.

Selectivity and excitability of upper-limb muscle activation during cervical transcutaneous spinal cord stimulation in humans

2021 ◽  
Author(s):  
Roberto M. de Freitas ◽  
Atsushi Sasaki ◽  
Dimitry G. Sayenko ◽  
Yohei Masugi ◽  
Taishin Nomura ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Upper Limb ◽  
Spinal Cord Stimulation ◽  
Muscle Activation ◽  
Anterior Neck ◽  
Hand Muscles ◽  
Ia Afferents ◽  
Arm Muscles ◽  
Muscle Responses ◽  
Transcutaneous Spinal Cord Stimulation

Cervical transcutaneous spinal cord stimulation (tSCS) efficacy for rehabilitation of upper-limb motor function was suggested to depend on recruitment of Ia afferents. However, selectivity and excitability of motor activation with different electrode configurations remains unclear. In this study, activation of upper-limb motor pools was examined with different cathode and anode configurations during cervical tSCS in 10 able-bodied individuals. Muscle responses were measured from six upper-limb muscles simultaneously. First, post-activation depression was confirmed with tSCS paired pulses (50 ms interval) for each cathode configuration (C6, C7, and T1 vertebral levels), with anode on the anterior neck. Selectivity and excitability of activation of the upper-limb motor pools were examined by comparing the recruitment curves (10-100 mA) of first evoked responses across muscles and cathode configurations. Our results showed that hand muscles were preferentially activated when the cathode was placed over T1 compared to the other vertebral levels, while there was no selectivity for proximal arm muscles. Furthermore, higher stimulation intensities were required to activate distal hand muscles than proximal arm muscles, suggesting different excitability thresholds between muscles. In a separate protocol, responses were compared between anode configurations (anterior neck, shoulders, iliac crests, and back), with one selected cathode configuration. The level of discomfort was also assessed. Largest muscle responses were elicited with the anode configuration over the anterior neck, while there were no differences in the discomfort. Our results therefore inform methodological considerations for electrode configuration to help optimize recruitment of Ia afferents during cervical tSCS.

scholarly journals Influence of Ball Impact Location on Racquet Kinematics, Forearm Muscle Activation and Shot Accuracy during the Forehand Groundstrokes in Tennis

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 89
Author(s):  
Masahiro Ikenaga ◽  
Nobue Okuma ◽  
Hiroki Nishiyama ◽  
Shinichiro Chiba ◽  
Katsutoshi Nishino ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Muscular Activity ◽  
Side Impact ◽  
Ball Impact ◽  
Tennis Players ◽  
Impact Location ◽  
Flexor Muscles ◽  
Flight Parameters ◽  
Extensor Carpi Radialis ◽  
Forearm Muscle

We aimed to clarify the effect of ball–racquet impact locations on the dynamic behavior of tennis racquet, the accuracy of shots and muscle activation of the forearm. Eight male intermediate tennis players performed ten forehand groundstrokes. A motion capture system was used to measure the motions of racquet, ball and human body at 2000 Hz, and electromyography (EMG) activities of wrist extensor and flexor muscles were measured simultaneously. The flight parameters of the ball were measured by ballistic measurement equipment. All shots were divided into tertiles based on ball impact location along the lateral axis of tennis racquet. We found that the off-center, upper-side impact induces a larger muscular activity in extensor carpi radialis. Passive radial deviation of the wrist occurring immediately after ball impact may account for this. Furthermore, the off-center, upper-side impact could be associated with a missed shot having a lower, outward ball launch angle.

scholarly journals No Relationship Between Preoperative and Early Postoperative Strength After ACL Reconstruction

2020 ◽  
Vol 29 (5) ◽  
pp. 583-587
Author(s):  
Pier Paolo Mariani ◽  
Luca Laudani ◽  
Jacopo E. Rocchi ◽  
Arrigo Giombini ◽  
Andrea Macaluso
Keyword(s):  
Acl Reconstruction ◽  
Cruciate Ligament ◽  
Knee Extensor ◽  
Quadriceps Strength ◽  
Maximal Voluntary Isometric Contraction ◽  
Extensor Muscles ◽  
Flexor Muscles ◽  
Anterior Cruciate ◽  
Tendon Autograft ◽  
Knee Extensor Muscles

Context: All rehabilitative programs before anterior cruciate ligament (ACL) reconstructive surgery, which are focused on recovery of proprioception and muscular strength, are defined as prehabilitation. While it has shown that prehabilitation positively affects the overall outcome after ACL reconstruction, it is still controversial whether preoperatively enhancing quadriceps strength has some beneficial effect on postoperative strength, mainly during the first period. Objective: To determine whether there is any relationship between preoperative and early postoperative quadriceps strength. Design: Case control. Setting: University research laboratory. Participants: Fifty-nine males (18–33 y; age: 23.69 [0.71] y) who underwent ACL reconstruction with patellar-tendon autograft were examined the day before surgery, and at 60 and 90 days after surgery. Main Outcome Measures: The limb symmetry index (LSI) was quantified for maximal voluntary isometric contraction of the knee extensor muscles and of the knee flexor muscles at 90° joint angle. A k-means analysis was performed on either quadriceps or hamstrings LSI before surgery to classify the patients in high and low preoperative LSI clusters. Differences in postoperative LSI were then evaluated between the high and low preoperative LSI clusters. Results: Following surgery, there were no differences in the quadriceps LSI between patients with high and low preoperative quadriceps LSI. Sixty days after surgery, the hamstrings LSI was higher in patients with high than low preoperative hamstrings LSI (84.0 [13.0]% vs 75.4 [15.9]%; P < .05). Conclusions: Findings suggest that quadriceps strength deficit is related to the ACL injury and increases further after the reconstruction without any correlation between the preoperative and postoperative values. Therefore, it appears that there is no need to delay surgery in order to increase the preoperative quadriceps strength before surgery.

scholarly journals Investigation of upper arm muscle activation for the progress monitoring in stroke rehabilitation

2018 ◽  
Author(s):  
Nor Hayati Ismail ◽  
Wan Khairunizam ◽  
Saiful Majid ◽  
Basri Nor Cahyadi ◽  
M. N. Rudzuan ◽  
...  
Keyword(s):  
Stroke Rehabilitation ◽  
Muscle Activation ◽  
Progress Monitoring ◽  
Upper Arm

Hydrothermal Field Experiment Simulating Steel Canister Embedded in Expansive Clay - Physical Behavior of the Clay

1991 ◽  
Vol 257 ◽  
Author(s):  
Roland Pusch ◽  
Ola Karnland ◽  
Alain Lajudie ◽  
Rosemarie Atabek
Keyword(s):  
Field Experiment ◽  
Physical Properties ◽  
Mineral Composition ◽  
Water Saturation ◽  
Expansive Clay ◽  
Physical Behavior ◽  
Gas Formation ◽  
Aluminum Compounds ◽  
Short Test ◽  
High Degree

ABSTRACTField heat experiments with kaolinite/smectite clay surrounding heaters in boreholes were conducted for 0.7 and 4 years with temperatures up to 170-180°C. The short test gave a high degree of water saturation even in the hottest part (> 75 %) and almost no change in physical properties and mineral composition. The long test gave a dry inner zone of claystone, indicating gas formation, and rich precipitation of silica/aluminum compounds and sulphate minerals. Brittleness characterized the hot parts and stiffening occurred also in the colder parts due to precipitation of silica and aluminum.

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