Matching Items (38)
Description
Muscular weakness is a common manifestation for Stroke survivors and for patients with Anterior Cruciate Ligament reconstruction leading to reduced functional independence, especially mobility. Several rigid orthotic devices are being designed to assist mobility. However, limitations in majority of these devices are: 1) that they are constrained only to level walking applications, 2) are mostly bulky and rigid lacking user comfort. For these reasons, rehabilitation using soft-robotics can serve as a powerful modality in gait assistance and potentially accelerate functional recovery. The characteristics of soft robotic exosuit is that it’s more flexible, delivers high power to weight ratio, and conforms with the user’s body structure making it a suitable choice. This work explores the implementation of an existing soft robotic exosuit in assisting knee joint mechanism during stair ascent for patients with muscular weakness. The exosuit assists by compensating the lack of joint moment and minimizing the load on the affected limb. It consists of two I-cross-section soft pneumatic actuators encased within a sleeve along with insole sensor shoes and control electronics. The exosuit actuators were mechanically characterized at different angles, in accordance to knee flexion in stair gait, to enable the generation of the desired joint moments. A linear relation between the actuator stiffness and internal pressure as a function of the knee angle was obtained. Results from this characterization along with the insole sensor outputs were used to provide assistance to the knee joint. Analysis of stair gait with and without the exosuit ‘active’ was performed, using surface electromyography (sEMG) sensors, for two healthy participants at a slow walking speed. Preliminary user testing with the exosuit presented a promising 16% reduction in average muscular activity of Vastus Lateralis muscle and a 3.6% reduction on Gluteus Maximus muscle during the stance phase and unrestrained motion during the swing phase of ascent thereby demonstrating the applicability of the soft-inflatable exosuit in rehabilitation.
ContributorsMuthukrishnan, Niveditha (Author) / Polygerinos, Panagiotis (Thesis advisor) / Lockhart, Thurmon (Committee member) / Peterson, Daniel (Committee member) / Arizona State University (Publisher)
Created2018
Description
Individuals fluent in sign language who have at least one deaf parent are considered native signers while those with non-signing, hearing parents are non-native signers. Musculoskeletal pain from repetitive motion is more common from non-natives than natives. The goal of this study was twofold: 1) to examine differences in upper extremity (UE) biomechanical measures between natives and non-natives and 2) upon creating a composite measure of injury-risk unique to signers, to compare differences in scores between natives and non-natives. Non-natives were hypothesized to have less favorable biomechanical measures and composite injury-risk scores compared to natives. Dynamometry was used for measurement of strength, electromyography for ‘micro’ rest breaks and muscle tension, optical motion capture for ballistic signing, non-neutral joint angle and work envelope, a numeric pain rating scale for pain, and the modified Strain Index (SI) as a composite measure of injury-risk. There were no differences in UE strength (all p≥0.22). Natives had more rest (natives 76.38%; non-natives 26.86%; p=0.002) and less muscle tension (natives 11.53%; non-natives 48.60%; p=0.008) for non-dominant upper trapezius across the first minute of the trial. For ballistic signing, no differences were found in resultant linear segment acceleration when producing the sign for ‘again’ (natives 27.59m/s2; non-natives 21.91m/s2; p=0.20). For non-neutral joint angle, natives had more wrist flexion-extension motion when producing the sign for ‘principal’ (natives 54.93°; non-natives 46.23°; p=0.04). Work envelope demonstrated the greatest significance when determining injury-risk. Natives had a marginally greater work envelope along the z-axis (inferior-superior) across the first minute of the trial (natives 35.80cm; non-natives 30.84cm; p=0.051). Natives (30%) presented with a lower pain prevalence than non-natives (40%); however, there was no significant difference in the modified SI scores (natives 4.70 points; non-natives 3.06 points; p=0.144) and no association between presence of pain with the modified SI score (r=0.087; p=0.680). This work offers a comprehensive analysis of all the previously identified UE biomechanics unique to signers and helped to inform a composite measure of injury-risk. Use of the modified SI demonstrates promise, although its lack of association with pain does confirm that injury-risk encompasses other variables in addition to a signer’s biomechanics.
ContributorsRoman, Gretchen Anne (Author) / Swan, Pamela (Thesis advisor) / Vidt, Meghan (Committee member) / Peterson, Daniel (Committee member) / Lockhart, Thurmon (Committee member) / Ofori, Edward (Committee member) / Arizona State University (Publisher)
Created2018
Description
This study investigated the effect of a small added load on postural stability in older adults. Sixteen healthy older adults (6 male, 10 female, age=72 ± 3.2y, height=172± 9.3 cm, weight=84± 7.6 kg) performed clinical measures of postural control with different loads placed on the shoulders (0%, 1% and 3% bodyweight). The functional reach test, comprising a forward, right and left lateral reach, along with COP data measured through the use of a force plate were the postural control measures utilized in this study. COP data used were COP sway velocity and COP mean sway area, in the form of a 95% confidence ellipse. During the COP trials, visual input (eyes open and eyes closed) and surface conditions (firm and foam) were varied to evaluate the effect of the loads under different conditions. Two trials of each measurement were performed for all tests, and participants were allowed rest intervals as needed. Anticipated results show a decreased reach distance of 8% in the forward direction, and a 7% decrease in the left and right lateral directions under a 1% bodyweight load. For expected results of COP velocity, there will be a 12% increase from baseline COP sway velocity in the 1% bodyweight condition. Anticipated results for COP sway area show a 39% increase in the eyes open firm surface, under a 1% bodyweight load, and a 40% increase under the 3% load. These expected results show a significant effect on postural control with a 1% and 3% bodyweight load placed on the shoulders of older adults. This information may be valuable in combatting the epidemic of falls seen among the elderly population, as part of an exercise program for improving balance and postural stability.
ContributorsScherwinski, Eric (Author) / Dounskaia, Natalia (Thesis director) / Vidt, Meghan (Committee member) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Introduction: Individuals with rotator cuff tears have been found to compensate in their movement patterns by using lower thoracohumeral elevation angles during certain tasks, as well as increased internal rotation of the shoulder (Vidt et al., 2016). Leading joint hypothesis suggests there is one leading joint that creates the foundation for the entire limb motion, and there are other subordinate joints which monitor the passive interaction torque and create a net torque aiding to limb motions required for the task. This experiment seeks to establish a better understanding of joint control strategies during a wide range of arm movements. Based on the leading joint hypothesis, we hypothesize that when a subject has a rotator cuff tear, their performance of planar and three-dimensional motions should be altered not only at the shoulder, which is often the leading joint, but also at other joints on the arm, such as the elbow and wrist. This paper will focus on the effect of normal aging on the control of the joints of the arm.
Methods: There were 4 groups of participants: healthy younger adults (n=14)(21.74 ± 1.97), healthy older adults (n=12)(55-75), older adults (n=4)(55-75) with a partial-thickness rotator cuff tear, and older adults (n=4)(55-75) with a full-thickness rotator cuff tear (RCT). All four groups completed strength testing, horizontal drawing and pointing tasks, and three dimensional (3D) activities of daily living. Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 12 reflective markers placed on the arm, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque on the different segments of the arm and interaction torque caused as a result of the multi-joint structure of human limbs. The number of tested participants for the minor RCT, and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article. Between the older adult control group and the young adult control group in the tasks upward reach to eye height and hair comb there were significant differences found between the groups. The differences were found in shorter overall time and distance between the two groups in the upward eye task.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. With available data, it can be concluded that healthy older adults use movement control strategies, such as shortening distance covered, decreasing time percentage in active joint phases, and increasing time percentage in passive joint phases, to account for atrophy along with other age-related declines in performance, such as a decrease in range of motion. This article is a part of a bigger project which aims to better understand how older adults with RCTs compensate for the decreased strength, the decreased range of motion, and the pain that accompany this type of injury. It is anticipated that the results of this experiment will lead to more research toward better understanding how to treat patients with RCTs.
Methods: There were 4 groups of participants: healthy younger adults (n=14)(21.74 ± 1.97), healthy older adults (n=12)(55-75), older adults (n=4)(55-75) with a partial-thickness rotator cuff tear, and older adults (n=4)(55-75) with a full-thickness rotator cuff tear (RCT). All four groups completed strength testing, horizontal drawing and pointing tasks, and three dimensional (3D) activities of daily living. Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 12 reflective markers placed on the arm, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque on the different segments of the arm and interaction torque caused as a result of the multi-joint structure of human limbs. The number of tested participants for the minor RCT, and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article. Between the older adult control group and the young adult control group in the tasks upward reach to eye height and hair comb there were significant differences found between the groups. The differences were found in shorter overall time and distance between the two groups in the upward eye task.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. With available data, it can be concluded that healthy older adults use movement control strategies, such as shortening distance covered, decreasing time percentage in active joint phases, and increasing time percentage in passive joint phases, to account for atrophy along with other age-related declines in performance, such as a decrease in range of motion. This article is a part of a bigger project which aims to better understand how older adults with RCTs compensate for the decreased strength, the decreased range of motion, and the pain that accompany this type of injury. It is anticipated that the results of this experiment will lead to more research toward better understanding how to treat patients with RCTs.
ContributorsFlores, Noah Mateo (Author) / Dounskaia, Natalia (Thesis director) / Vidt, Meghan (Committee member) / College of Health Solutions (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Introduction: Individuals with rotator cuff tears (RCT) have been found to compensate in their movement patterns by using lower thoracohumeral elevation angles during certain tasks, as well as increased internal rotation of the shoulder (Vidt et al., 2016). The leading joint hypothesis (LJH) suggests there is one leading joint that creates the foundation for the entire limb motion, and there are other subordinate joints that monitor the passive interaction torque (IT) and create a net torque (NT) aiding to limb motions required for the task. This experiment hopes to establish a better understanding of joint control strategies during a wide range of arm movements. Based off of the LJH, we hypothesize that when a subject has a rotator cuff tear, their performance of planar and three- dimensional motions should be altered not only at the shoulder, which is often the leading joint, but also at other joints on the arm such as the elbow and wrist.
Methods: There were 3 groups of participants: healthy younger adults (age 21.74 ± 1.97), healthy older adult controls (age 69.53 ± 6.85), and older adults with a RCT (age 64.33 ± 4.04). All three groups completed strength testing, horizontal drawing and pointing tasks, and three-dimensional (3D) activities of daily living (ADLs). Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 13 reflective markers placed on the arm and trunk, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). During these tasks, electromyography (EMG) electrodes were placed on 12 muscles along the arm that affect shoulder, elbow, and wrist rotation. Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque (GT) on the different segments of the arm and IT caused as a result the multi-joint structure of human limbs. The number of tested participants for the healthy older adults and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. This article is a part of a bigger project which hopes to get a better understanding of how older adults adjust to large passive torques acting on the arm during 3D movements and how older adults with RCTs compensate for the decreased strength, the decreased range of motion (ROM), and the pain that accompany these types of tears. Hopefully the results of this experiment lead to more research toward better understanding how to treat patients with RCTs.
Methods: There were 3 groups of participants: healthy younger adults (age 21.74 ± 1.97), healthy older adult controls (age 69.53 ± 6.85), and older adults with a RCT (age 64.33 ± 4.04). All three groups completed strength testing, horizontal drawing and pointing tasks, and three-dimensional (3D) activities of daily living (ADLs). Kinematic and kinetic variables of the arm were obtained during horizontal and 3D tasks using data from 13 reflective markers placed on the arm and trunk, 8 motion capture cameras, and Cortex motion capture software (Motion Analysis Corp., Santa Rosa, CA). During these tasks, electromyography (EMG) electrodes were placed on 12 muscles along the arm that affect shoulder, elbow, and wrist rotation. Strength testing tasks were measured using a dynamometer. All strength testing and 3D tasks were completed for three trials and horizontal tasks were completed for two trials.
Results: Results of the younger adult participants showed that during the forward portion of seven 3D tasks, there were four phases of different joint control mechanics seen in a majority of the movements. These phases included active rotation of both the shoulder and the elbow joint, active rotation of the shoulder with passive rotation of the elbow, passive rotation of the shoulder with active rotation of the elbow, and passive rotation of both the shoulder and the elbow. Passive rotation during movements was a result of gravitational torque (GT) on the different segments of the arm and IT caused as a result the multi-joint structure of human limbs. The number of tested participants for the healthy older adults and RCT older adults groups is not yet high enough to produce significant results and because of this their results are not reported in this article.
Discussion: Through the available results, multiple phases were found where one or both of the joints of the arm moved passively which further supports the LJH and extends it to include 3D movements. This article is a part of a bigger project which hopes to get a better understanding of how older adults adjust to large passive torques acting on the arm during 3D movements and how older adults with RCTs compensate for the decreased strength, the decreased range of motion (ROM), and the pain that accompany these types of tears. Hopefully the results of this experiment lead to more research toward better understanding how to treat patients with RCTs.
ContributorsGarnica, Nicholas (Co-author) / Perrine, Austin (Co-author) / Schalk, Courtney (Co-author) / Dounskaia, Natalia (Thesis director) / Vidt, Meghan (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Background: Falls are a leading cause of injury in older adults with roughly 1 in 4 American's over the age of 65 experiencing a fall. Research that looks at reactive stepping, or the steps a person takes when they encounter a loss of balance, is sparse. Whether a specific aspect of reactive stepping can be linked to falls has yet to be determined. Purpose: The purpose of this study was to determine which reactive stepping characteristics may be correlated with falls in from community dwelling older adults. Methods: 54 older adults (11 fallers & 43 non-fallers) underwent 3 "postural perturbations", in which they leaned back into the testers hands and were released, resulting in one or more reactive steps. Inertial sensors (APDM, inc.) were used to measure participant movement and Quantify reactive steps. Step length and step latency, which is the time it takes for an individual to perform a step, were the primary outcomes measured, along with time to stabilization, number of steps taken, and time until first foot strike. Results: Neither step length or step latency were significantly different in fallers compared to non-fallers (p=0.537 and p=0.431, respectively). However, four square step test was significantly different between the populations (p= 0.045). Conclusions: These results showed that four square step test may be more closely related to falls than step length or latency. When performing fall prevention training, or working with an individual at risk for falling, it may be more beneficial to focus on four square step test and the changes in direction associated with it, as opposed to other stepping characteristics in order to improve their fall risk.
ContributorsPreschler, Rachael (Author) / Peterson, Daniel (Thesis director) / Schaefer, Sydney (Committee member) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
According to the Center for Disease Control, 1 in every 3 individuals will fall in their lifetime. Treadmill perturbation training has been a beneficial tool to increase reactive postural control and decrease the amount of falls. This study looked at the extent of the training effects on 29 healthy young adults to evaluate if stepping improvements in one direction could generalize to improvements in the quality of stepping in other directions. Outcome variables of Margin of Stability (MOS), step length, and step latency were evaluated for all 15 participants trained with forward perturbations and 14 participants trained with backward perturbations. From the paired t-tests, there were limited significant improvements in stepping with regards to motor learning and generalization. The only significant outcome was an increase in step length for the participants who trained in the backward direction (p=0.014; p<0.05). However, this significant increase in step length for this backward group did not generalize when the participants stepped in the forward direction post training. From the correlation tests, there was a significant, moderate correlation between motor learning and generalization (rho =0.527, p= 0.043; p<0.05), thus suggesting there may be a relationship between the amount of learning and the amount of generalization observed. Further evaluation of the second step and the foot motion during stepping may reveal more information and explain the changes in stepping to describe how healthy young adults were able to regain balance with each perturbation given.
ContributorsNowak, Rachael Teresa (Author) / Peterson, Daniel (Thesis director) / Dounskaia, Natalia (Committee member) / School of Nutrition and Health Promotion (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2018-12
Description
In motor training, transfer is defined as the gain/loss of performance in one task as a result of training on another. In our laboratory, we have observed that training on a multi-joint coordination task (which simulates arm and wrist movement when feeding) transfers to a dexterity task (which simulates finger and hand movement when dressing), such that there are improvements in the dexterity task that emerge without having trained on that specific task. More recently, we have shown that the dexterity task transfers to the multi-joint coordination task. These collective findings suggest that there are shared movement patterns between these two functional motor tasks that may yield this bi-directional transfer effect. Therefore, the objective of this thesis project was to collect kinematic data of the hand to use in future principal component analyses to better understand the underlying mechanism of transfer between these two functional motor tasks. The joint angles of the hand were recorded during twenty second trials of the multi-joint coordination task and the dexterity task. The ranges of motion for the joints in the hand during naïve performance of both motor tasks were analyzed. From a linear regression analysis, we observe that the hand’s ranges of motion were strongly correlated between the two tasks, which suggests that these two functionally different tasks may share movement patterns in terms of joint angles. This similarity of joint angles of the hand may play a role in why we observe this bi-directional transfer between the dexterity and multi-joint coordination tasks. Following neurological injury, patients participate in physical therapy in order to retrain their nervous system to restore lost motor function(s). If patients can only practice a limited number of activities in therapy, our data suggest that other activities may also improve through transfer of training. Kinematic data collection may inform how much a patient improves with motor training and why there may be an improvement in untrained motor tasks.
ContributorsConnor, Sydney Christine (Author) / Schaefer, Sydney (Thesis director) / Peterson, Daniel (Committee member) / Harrington Bioengineering Program (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Rotator cuff tears (RCT) can affect up to 50% of the older population and this injury is typically associated with functional deficits and shoulder pain that prevent people from living a typical lifestyle. Particularly in an older population, this type of pain increases functional dependency on others and can hinder the possibility of independent living. An area of shoulder pathology that lacks research is the functional differences in symptomatic and asymptomatic tears on activities of daily living (ADL). In order to more fully understand the functional presentations associated with each of these types of tears, it is critical that we evaluate the various mechanisms that contribute to altered movement patterns. Understanding these different compensatory patterns between asymptomatic and symptomatic tears will allow for a better understanding of the presentation of this shoulder pathology and provide new insight for diagnostic and rehabilitation purposes. Therefore, the objective of this study is to quantify kinematic differences of daily upper limb movements between symptomatic and asymptomatic RCTs in an older population. To accomplish this goal, we will be using motion capture and electromyography to assess typical ADL movements and their associated muscle activation patterns during 2D and 3D tasks in older adults (≥55 years). Strength and shoulder range of motion measures will also be taken, as well as self-reported measures of function and pain. Through this project, we seek to understand the presentation of RCTs and what characteristics are associated with symptoms. Long term, outcomes from this work will be used to develop a more standardized approach to early detection and treatment of this common shoulder pathology in the older adult population.
ContributorsFujita, Hikaru Ashley (Author) / Vidt, Meghan (Thesis director) / Dounskaia, Natalia (Committee member) / School of Nutrition and Health Promotion (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Research on joint control during arm movements in adults has led to the development of the Leading Joint Hypothesis (LJH), which states that the central nervous system takes advantage of interaction torque (IT) and muscle torque (MT) to produce movements with maximum efficiency in the multi-jointed limbs of the human body. A gap in knowledge exists in determining how this mature pattern of joint control develops in children. Prior research focused on the kinematics of joint control for children below the age of three; however, not much is known about interjoint coordination with respect to MT and IT in school-aged children. In the present study, joint control at the shoulder, elbow, and wrist during drawing of five shapes was investigated. A random sample of nine typically developing children ages 6 to 12 served as subjects. The task was to trace with the index finger a template placed on a horizontal table. The template consisted of a circle, horizontal, vertical, right-diagonal, and left-diagonal line. Analysis of muscle torque contribution (MTC) revealed the individual roles of MT and IT in the shoulder, elbow, and wrist joints. During drawing of the horizontal line, which requires the most difficult joint control pattern in adults because it does not allow the use of IT for joint rotation, joint control was found to change through development. For the youngest children, the function of elbow MT modified to suppress IT, thereby producing large elbow rotation. The oldest children simplified this by using the shoulder as the principal joint of movement production and with decreased assistance from the elbow. For the other four drawing movements, differences in the pattern of joint control used by all of the subjects was unaffected by an increase in age. Overall, the results suggest that in children above 6 years of age, minor changes in joint control occur during drawing of relatively simple movements. The limited effect of age that was observed could be related to the restriction of movements to the horizontal plane. For a future study, three-dimensional movements that provide more freedom in joint control due to redundancy of degrees of freedom could be more informative about developmental changes in joint coordination.
ContributorsKemmou, Nadaa (Co-author) / Way, Victoria (Co-author) / Dounskaia, Natalia (Thesis director) / Vidt, Meghan (Committee member) / School of Nutrition and Health Promotion (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12