Leg Joint Stiffness Affects Dynamics of Backward Falling From Standing Height: A Simulation Work

2020 ◽  
Author(s):  
Mu Qiao ◽  
Feng Yang
Keyword(s):  
Older Adults ◽  
Lower Limb ◽  
Joint Stiffness ◽  
Biomechanical Properties ◽  
Knee Joints ◽  
Human Model ◽  
Loss Of Consciousness ◽  
Rotational Stiffness ◽  
Ankle Stiffness ◽  
The Impact

Abstract Falling backward can lead to injuries including hip fracture, back injury, and traumatic brain impact among older adults. A loss of consciousness is associated with falling backward and accounts for about 13% of all falls among older adults. Little is known about the dynamics of backward falls, such as the falling duration, the impact severity, and how the fall dynamics are affected by the biomechanical properties of the lower limb joints, particularly the rotational stiffness. The purpose of this study was to investigate the influence of the stiffness of individual leg joints on the dynamics of backward falls after losing consciousness in terms of the falling duration and impact velocities. Based on a 15-segment human model, we simulated the process of falling backwards by sweeping the parameter space of ankle, knee, and hip's stiffness varying from 0 to 8.73 Nm/deg (or 500 Nm/rad). The results revealed that the falling duration and impact speeds of the head and hip ranged from 0.27 to 0.63 s, 2.65 to 7.88 m/s, and 0.35 to 3.36 m/s, respectively, when the stiffness of the leg joints changed within their limits. Overall, the influence of the joint stiffness on the falling dynamics (falling duration and impact speed) is comparable between hip and knee joints. Whereas, ankle stiffness showed little influence on the backward falling dynamics. Our findings could provide references for designing protective devices to prevent impact-induced injuries after a backward fall.

scholarly journals Adjustments with running speed reveal neuromuscular adaptations during landing associated with high mileage running training

2017 ◽  
Vol 122 (3) ◽  
pp. 653-665 ◽  
Author(s):  
Jasper Verheul ◽  
Adam C. Clansey ◽  
Mark J. Lake
Keyword(s):  
Lower Limb ◽  
Muscle Activation ◽  
Joint Stiffness ◽  
Thigh Muscle ◽  
Running Speed ◽  
Running Training ◽  
Knee Stiffness ◽  
Peak Knee ◽  
The Impact ◽  
Weight Acceptance

It remains to be determined whether running training influences the amplitude of lower limb muscle activations before and during the first half of stance and whether such changes are associated with joint stiffness regulation and usage of stored energy from tendons. Therefore, the aim of this study was to investigate neuromuscular and movement adaptations before and during landing in response to running training across a range of speeds. Two groups of high mileage (HM; >45 km/wk, n = 13) and low mileage (LM; <15 km/wk, n = 13) runners ran at four speeds (2.5–5.5 m/s) while lower limb mechanics and electromyography of the thigh muscles were collected. There were few differences in prelanding activation levels, but HM runners displayed lower activations of the rectus femoris, vastus medialis, and semitendinosus muscles postlanding, and these differences increased with running speed. HM runners also demonstrated higher initial knee stiffness during the impact phase compared with LM runners, which was associated with an earlier peak knee flexion velocity, and both were relatively unchanged by running speed. In contrast, LM runners had higher knee stiffness during the slightly later weight acceptance phase and the disparity was amplified with increases in speed. It was concluded that initial knee joint stiffness might predominantly be governed by tendon stiffness rather than muscular activations before landing. Estimated elastic work about the ankle was found to be higher in the HM runners, which might play a role in reducing weight acceptance phase muscle activation levels and improve muscle activation efficiency with running training. NEW & NOTEWORTHY Although neuromuscular factors play a key role during running, the influence of high mileage training on neuromuscular function has been poorly studied, especially in relation to running speed. This study is the first to demonstrate changes in neuromuscular conditioning with high mileage training, mainly characterized by lower thigh muscle activation after touch down, higher initial knee stiffness, and greater estimates of energy return, with adaptations being increasingly evident at faster running speeds.

Sex and Stride Impact Joint Stiffness During Loaded Running

2020 ◽  
pp. 1-7
Author(s):  
Tyler N. Brown ◽  
AuraLea C. Fain ◽  
Kayla D. Seymore ◽  
Nicholas J. Lobb
Keyword(s):  
Range Of Motion ◽  
Analysis Of Variance ◽  
Lower Limb ◽  
Injury Risk ◽  
Mixed Model ◽  
Joint Stiffness ◽  
Mixed Model Analysis ◽  
Joint Compliance ◽  
Ankle Stiffness ◽  
Flexion Moment

This study determined changes in lower limb joint stiffness when running with body-borne load, and whether they differ with stride or sex. Twenty males and 16 females had joint stiffness quantified when running (4.0 m/s) with body-borne load (20, 25, 30, and 35 kg) and 3 stride lengths (preferred or 15% longer and shorter). Lower limb joint stiffness, flexion range of motion (RoM), and peak flexion moment were submitted to a mixed-model analysis of variance. Knee and ankle stiffness increased 19% and 6% with load (P < .001, P = .049), but decreased 8% and 6% as stride lengthened (P = .004, P < .001). Decreased knee RoM (P < .001, 0.9°–2.7°) and increased knee (P = .007, up to 0.12 N.m/kg.m) and ankle (P = .013, up to 0.03 N.m/kg.m) flexion moment may stiffen joints with load. Greater knee (P < .001, 4.7°–5.4°) and ankle (P < .001, 2.6°–7.2°) flexion RoM may increase joint compliance with longer strides. Females exhibited 15% stiffer knee (P = .025) from larger reductions in knee RoM (4.3°–5.4°) with load than males (P < .004). Stiffer lower limb joints may elevate injury risk while running with load, especially for females.

scholarly journals Differential genomic responses in old vs. young humans despite similar levels of modest muscle damage after resistance loading

2010 ◽  
Vol 40 (3) ◽  
pp. 141-149 ◽  
Author(s):  
Anna E. Thalacker-Mercer ◽  
Louis J. Dell'Italia ◽  
Xiangqin Cui ◽  
James M. Cross ◽  
Marcas M. Bamman
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Muscle Damage ◽  
Stress Responses ◽  
Structural Integrity ◽  
Model Systems ◽  
Human Model ◽  
Young Subjects ◽  
The Impact

Across numerous model systems, aging skeletal muscle demonstrates an impaired regenerative response when exposed to the same stimulus as young muscle. To better understand the impact of aging in a human model, we compared changes to the skeletal muscle transcriptome induced by unaccustomed high-intensity resistance loading (RL) sufficient to cause moderate muscle damage in young (37 yr) vs. older (73 yr) adults. Serum creatine kinase was elevated 46% 24 h after RL in all subjects with no age differences, indicating similar degrees of myofiber membrane wounding by age. Despite this similarity, from genomic microarrays 318 unique transcripts were differentially expressed after RL in old vs. only 87 in young subjects. Follow-up pathways analysis and functional annotation revealed among old subjects upregulation of transcripts related to stress and cellular compromise, inflammation and immune responses, necrosis, and protein degradation and changes in expression (up- and downregulation) of transcripts related to skeletal and muscular development, cell growth and proliferation, protein synthesis, fibrosis and connective tissue function, myoblast-myotube fusion and cell-cell adhesion, and structural integrity. Overall the transcript-level changes indicative of undue inflammatory and stress responses in these older adults were not mirrored in young subjects. Follow-up immunoblotting revealed higher protein expression among old subjects for NF-κB, heat shock protein (HSP)70, and IL-6 signaling [total and phosphorylated signal transducer and activator of transcription (STAT)3 at Tyr705]. Together, these novel findings suggest that young and old adults are equally susceptible to RL-mediated damage, yet the muscles of older adults are much more sensitive to this modest degree of damage—launching a robust transcriptome-level response that may begin to reveal key differences in the regenerative capacity of skeletal muscle with advancing age.

The Impact of Subjective and Objective Hearing Loss on Cognition and Memory in Older Adults

2015 ◽  
Vol 20 (2) ◽  
pp. 49-57 ◽  
Author(s):  
Yvonne Rogalski ◽  
Amy Rominger
Keyword(s):  
Older Adults ◽  
Hearing Loss ◽  
Reading Aloud ◽  
Cognitive Testing ◽  
Professional Collaboration ◽  
Cognitive Screening ◽  
Speech Language Pathologist ◽  
Text Passage ◽  
The Impact ◽  
Audiologic Evaluation

For this exploratory cross-disciplinary study, a speech-language pathologist and an audiologist collaborated to investigate the effects of objective and subjective hearing loss on cognition and memory in 11 older adults without hearing loss (OAs), 6 older adults with unaided hearing loss (HLOAs), and 16 young adults (YAs). All participants received cognitive testing and a complete audiologic evaluation including a subjective questionnaire about perceived hearing difficulty. Memory testing involved listening to or reading aloud a text passage then verbally recalling the information. Key findings revealed that objective hearing loss and subjective hearing loss were correlated and both were associated with a cognitive screening test. Potential clinical implications are discussed and include a need for more cross-professional collaboration in assessing older adults with hearing loss.

The Impact of TimeSlips on Undergraduate Students in Service Learning With Older Adults

2020 ◽  
pp. 1-8
Author(s):  
Sabine Heuer
Keyword(s):  
Older Adults ◽  
Service Learning ◽  
Undergraduate Students ◽  
Attitude Scale ◽  
Evidence Based ◽  
Attitudes Toward Older Adults ◽  
Students Attitudes ◽  
Attitude Shift ◽  
The Impact ◽  
Journal Entries

Purpose Future speech-language pathologists are often unprepared in their academic training to serve the communicative and cognitive needs of older adults with dementia. While negative attitudes toward older adults are prevalent among undergraduate students, service learning has been shown to positively affect students' attitudes toward older adults. TimeSlips is an evidence-based approach that has been shown to improve health care students' attitudes toward older adults. The purpose of this study is to explore the change in attitudes in speech-language pathology students toward older adults using TimeSlips in service learning. Method Fifty-one students participated in TimeSlips service learning with older adults and completed the Dementia Attitude Scale (DAS) before and after service learning. In addition, students completed a reflection journal. The DAS data were analyzed using nonparametric statistics, and journal entries were analyzed using a qualitative analysis approach. Results The service learners exhibited a significant increase in positive attitude as indexed on the DAS. The reflective journal entries supported the positive change in attitudes. Conclusions A noticeable attitude shift was indexed in reflective journals and on the DAS. TimeSlips is an evidence-based, patient-centered approach well suited to address challenges in the preparation of Communication Sciences and Disorders students to work with the growing population of older adults.

The impact of caffeine on older adults' name learning

2011 ◽  
Author(s):  
Elizabeth A. Crandall ◽  
Lori E. James
Keyword(s):  
Older Adults ◽  
The Impact

Fear of memory decline predicts lower quality of life and increased memory failures in older adults: Preliminary findings from a novel fear-avoidance of memory decline scale.

2020 ◽  
Author(s):  
Francesca Farina ◽  
Marc Patrick Bennett ◽  
James William Griffith ◽  
Bert Lenaert
Keyword(s):  
Quality Of Life ◽  
Older Adults ◽  
Memory Performance ◽  
Fear Avoidance ◽  
Subjective Memory ◽  
Memory Decline ◽  
General Anxiety ◽  
Quality Of Life Scale ◽  
The Impact

Evidence concerning the impact of fear of memory decline on health-related outcomes is limited. To determine the relationship between fear-avoidance of memory decline, quality of life and subjective memory in older adults using a novel scale to measure fear of memory decline. Sixty-seven older adults (59-81 years) completed a 23-item self-report questionnaire designed to capture experiential, cognitive and behavioral components of fear of memory decline, known as the fear and avoidance of memory decline (FAM) scale. Memory performance was assessed using the Wechsler Memory Scale (WMS-IV) and the Memory Failures Scale (MFS). General anxiety was assessed using the Depression, Anxiety and Stress Scales (DASS) and the Geriatric Anxiety Inventory (GAI). Quality of life was assessed using the Older Person’s Quality of Life scale (OPQOL-35). The FAM scale demonstrated good reliability and validity. Three latent factors were observed including: (1) fear-avoidance, (2) problematic beliefs and (3) resilience. After adjusting for age, education, memory performance and general anxiety, higher fear-avoidance predicted lower quality of life (p=.021) and increased memory failures (p=.022). Increased fear of memory decline predicts lower quality of life and subjective memory failures in healthy older adults. Based on these findings, we propose a preliminary fear-avoidance model that explains the development and maintenance of dementia-related functional disability in terms of psychological processes.

The Impact of Stressful Life Events and Social Support on Drinking among Older Adults: A General Population Survey

1992 ◽  
Vol 35 (2) ◽  
pp. 99-123 ◽  
Author(s):  
Karen M. Jennison
Keyword(s):  
Social Support ◽  
Older Adults ◽  
Life Events ◽  
Stressful Life Events ◽  
Prolonged Exposure ◽  
Drinking Behavior ◽  
National Sample ◽  
Stressful Life ◽  
Stress Buffering ◽  
The Impact

This article is an analysis of stressful life events, the buffering hypothesis, and alcohol use in a national sample of 1,418 respondents 60 years of age and over. The results indicate that older adults who experience stressful losses are significantly more likely to drink excessively than those who have not experienced such losses or who have experienced them to a lesser extent. Increased drinking among older adults may therefore be a reaction to life circumstances in which alcohol represents an attempt to cope with traumatic loss, personal as well as within the kinship network. Supportive resources of spouse, family, friends, and church appear to have a stress-buffering effects that reduces the excessive-drinking response to life crisis. Data suggest, however, that older persons are vulnerable to the magnitude of losses experienced as they grow older and lose more of their family, friends, and peers. These stressors appear to seriously impact their drinking behavior and are not effectively buffered. Respondents report that drinking may increase during periods of prolonged exposure to emotionally depleting life change and loss, when supportive needs may exceed the capacities of personal and social support resources.

scholarly journals Reliability of Bi-Axial Ankle Stiffness Measurement in Older Adults

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1162
Author(s):  
Hogene Kim ◽  
Sangwoo Cho ◽  
Hwiyoung Lee
Keyword(s):  
Older Adults ◽  
Range Of Motion ◽  
Angular Displacement ◽  
Plantar Flexion ◽  
Significant Negative Correlation ◽  
Talocrural Joint ◽  
Ankle Foot Orthosis ◽  
Ankle Stiffness ◽  
Ankle Movement ◽  
Test Retest Reliability

This study involves measurements of bi-axial ankle stiffness in older adults, where the ankle joint is passively moved along the talocrural and subtalar joints using a custom ankle movement trainer. A total of 15 elderly individuals participated in test–retest reliability measurements of bi-axial ankle stiffness at exactly one-week intervals for validation of the angular displacement in the device. The ankle’s range of motion was also compared, along with its stiffness. The kinematic measurements significantly corresponded to results from a marker-based motion capture system (dorsi-/plantar flexion: r = 0.996; inversion/eversion: r = 0.985). Bi-axial ankle stiffness measurements showed significant intra-class correlations (ICCs) between the two visits for all ankle movements at slower (2.14°/s, ICC = 0.712) and faster (9.77°/s, ICC = 0.879) speeds. Stiffness measurements along the talocrural joint were thus shown to have significant negative correlation with active ankle range of motion (r = −0.631, p = 0.012). The ankle movement trainer, based on anatomical characteristics, was thus used to demonstrate valid and reliable bi-axial ankle stiffness measurements for movements along the talocrural and subtalar joint axes. Reliable measurements of ankle stiffness may help clinicians and researchers when designing and fabricating ankle-foot orthosis for people with upper-motor neuron disorders, such as stroke.

scholarly journals The Geriatric Medication Game to Raise Community Pharmacists’ Awareness on Older Adults’ Day-to-Day Challenges

2021 ◽  
pp. 1-6
Author(s):  
Aisha F. Badr
Keyword(s):  
Older Adults ◽  
Saudi Arabia ◽  
Learning Process ◽  
Community Pharmacists ◽  
The Elderly ◽  
Learning Activity ◽  
Simulation Games ◽  
Self Reflection ◽  
Satisfaction Rate ◽  
The Impact

<b><i>Introduction:</i></b> In Saudi Arabia; it is estimated that the elderly (aged 60 and above) would reach up to (22.9%) by 2050, compared to (5.6%) in 2017. Simulation games have proven to be a useful and effective method of education in pharmacy schools, as it actively involves participants in the learning process. The objective of this study was to examine the impact of the modified geriatric medication game on community pharmacists’ awareness and attitudes toward older adults with common disabilities. <b><i>Methods:</i></b> A modified geriatric medication game was adopted to stimulate both physical and sensory disabilities in older adults. A total of 9 community pharmacists were gathered in 1 room and were asked to play 2 scenarios each. Self-reflection was assessed and ground theories were analyzed. <b><i>Results:</i></b> All pharmacists felt frustration and anger playing the game (100%), followed by becoming more aware of the extra time and guidance needed with older adults and realized how disabling chronic diseases could be, and felt they needed to improve common perceived attitude towards the elderly (88.89%). Pharmacists also felt empathy, sympathy, and compassion towards this population, needed improvement of common perceived attitude towards older adults, and felt the need to double check with older adults if they have any disabilities before counseling (77.78%). Finally, over half pharmacists (55.5%) wished they had more training on geriatrics during pharmacy school and the need for further review of Beer’s criteria. All pharmacists were satisfied with the game and recommended it to all community pharmacists. <b><i>Conclusion:</i></b> Simulation games are a great way to strengthen awareness and change practice accordingly. Pharmacists improved their awareness and attitude towards the elderly and reported a positive perceived value of this learning activity; with a 100% satisfaction rate. Adding a geriatric course with simulation component is recommended for better geriatric care.

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