Musculoskeletal System Commons^™

Correction To: Hif Prolyl Hydroxylase Inhibition Protects Skeletal Muscle From Eccentric Contraction Induced Injury, Andrew N. Billin, Samuel E. Honeycutt, Alan V. Mcdougal, Jaclyn P. Kerr, Zhe Chen, Johannes M. Freudenberg, Deepak K. Rajpal, Guizhen Luo, Henning Fritz Kramer, Robert S. Geske, Frank Fang, Bert Yao, Richard V. Clark, John Lepore, Alex Cobitz, Ram Miller, Kazunori Nosaka, Aaron C. Hinken, Alan J. Russell

Research outputs 2014 to 2021

Following publication of the original article [1], the authors flagged that there is a discrepancy with the Availability of data and materials statement on page 12 of the article.

Femoroacetabular Impingement As A Complication Of Acetabular Fracture Fixation, David A. Zuelzer, Christopher B. Hayes, Raymond D. Wright, Stephen T. Duncan

Orthopaedic Surgery and Sports Medicine Faculty Publications

Case

We present the case of a thirteen-year-old female who sustained a posterior wall acetabular fracture dislocation. She underwent urgent closed reduction and subsequent uncomplicated open reduction and internal fixation. Post reduction computed tomography demonstrated a concentrically reduced hip joint with no evidence of femoroacetabular impingement (FAI). She subsequently healed her fracture and returned to running activities; however, one year later presented with aching pain in her thigh. Radiographs demonstrated the development of a large osseous prominence on her anterolateral femoral neck consistent with femoroacetabular impingement. Based on these findings she was evaluated by a hip preservation specialist. She subsequently …

The Relationship Between Feeding Type And Temporomandibular Joint Morphology In Superfamily Musteloidea, Travis L. Garvin

Masters Theses

Many studies have focused on the soft tissue analysis of carnivores and have demonstrated a relationship between feeding biomechanics and feeding types. Herbivores and omnivores rely heavily on anteroposterior and helical movement of the mandible and teeth for the breakdown of fibrous foods resulting in a flat mandibular fossa while the function of the carnivore TMJ is different, as they need a much stable joint for ripping and tearing of the flesh. I aim to look at whether the bony morphology of the temporomandibular joint (TMJ) can be directly related to feeding type, specifically in the superfamily Musteloidea. I sampled …

A Multicenter Study To Evaluate Pulmonary Function In Osteogenesis Imperfecta., Allison Tam, Shan Chen, Evan Schauer, Ingo Grafe, Venkata Bandi, Jay R. Shapiro, Robert D. Steiner, Peter A. Smith, Michael B. Bober, Tracy Hart, David Cuthbertson, Jeffrey Krischer, Mary Mullins, Peter H. Byers, Robert A. Sandhaus, Michaela Durigova, Francis H. Glorieux, Frank Rauch, Vernon Reid Sutton, Brendan Lee, Members Of The Brittle Bone Disorders Consortium, Eric T. Rush, Sandesh C S Nagamani

Manuscripts, Articles, Book Chapters and Other Papers

Pulmonary complications are a significant cause for morbidity and mortality in osteogenesis imperfecta (OI). However, to date, there have been few studies that have systematically evaluated pulmonary function in individuals with OI. We analyzed spirometry measurements, including forced vital capacity (FVC) and forced expiratory volume in the first second (FEV₁ ), in a large cohort of individuals with OI (n = 217) enrolled in a multicenter, observational study. We show that individuals with the more severe form of the disease, OI type III, have significantly reduced FVC and FEV₁ which do not follow the expected trends of the …

Anticipatory Postural Adjustments And Spatial Organization Of Motor Cortex: Evidence Of Adaptive Compensations In Healthy Older Adults, Jo Armour Smith, Beth E. Fisher

Physical Therapy Faculty Articles and Research

During anticipated postural perturbations induced by limb movement, the central nervous system generates anticipatory postural adjustments (APAs) in the trunk and hip musculature to minimize disturbances to equilibrium. Age-related changes in functional organization of the nervous system may contribute to changes in APAs in healthy older adults. Here we examined if altered APAs of trunk/hip musculature in older adults are accompanied by changes in the representation of these muscles in motor cortex. Twelve healthy older adults, 5 with a history of falls and 7 nonfallers, were compared with 13 young adults. APAs were assessed during a mediolateral arm raise task …

Hif Prolyl Hydroxylase Inhibition Protects Skeletal Muscle From Eccentric Contraction-Induced Injury, Andrew N Billin, Samuel E Honeycutt, Alan V Mcdougal, Jaclyn P Kerr, Zhe Chen, Johannes M Freudenberg, Deepak K Rajpal, Guizhen Luo, Henning Fritz Kramer, Robert S Geske, Frank Fang, Bert Yao, Richard V Clark, John Lepore, Alex Cobitz, Ram Miller, Kazunori Nosaka, Aaron C Hinken, Alan J Russell

Research outputs 2014 to 2021

BACKGROUND: In muscular dystrophy and old age, skeletal muscle repair is compromised leading to fibrosis and fatty tissue accumulation. Therefore, therapies that protect skeletal muscle or enhance repair would be valuable medical treatments. Hypoxia-inducible factors (HIFs) regulate gene transcription under conditions of low oxygen, and HIF target genes EPO and VEGF have been associated with muscle protection and repair. We tested the importance of HIF activation following skeletal muscle injury, in both a murine model and human volunteers, using prolyl hydroxylase inhibitors that stabilize and activate HIF.

METHODS: Using a mouse eccentric limb injury model, we characterized the protective effects …

A Novel Tetracycline-Responsive Transgenic Mouse Strain For Skeletal Muscle-Specific Gene Expression, Masahiro Iwata, Davis A. Englund, Yuan Wen, Cory M. Dungan, Kevin A. Murach, Ivan J. Vechetti Jr., Christopher B. Mobley, Charlotte A. Peterson, John J. Mccarthy

Center for Muscle Biology Faculty Publications

Background: The tetracycline-responsive system (Tet-ON/OFF) has proven to be a valuable tool for manipulating gene expression in an inducible, temporal, and tissue-specific manner. The purpose of this study was to create and characterize a new transgenic mouse strain utilizing the human skeletal muscle α-actin (HSA) promoter to drive skeletal muscle-specific expression of the reverse tetracycline transactivator (rtTA) gene which we have designated as the HSA-rtTA mouse.

Methods: To confirm the HSA-rtTA mouse was capable of driving skeletal muscle-specific expression, we crossed the HSA-rtTA mouse with the tetracycline-responsive histone H2B-green fluorescent protein (H2B-GFP) transgenic mouse in order to label myonuclei.

Results: …

The Chapman Bone Algorithm: A Diagnostic Alternative For The Evaluation Of Osteoporosis, Elise Levesque, Anton Ketterer, Wajiha Memon, Cameron James, Noah Barrett, Cyril Rakovski, Frank Frisch

Mathematics, Physics, and Computer Science Faculty Articles and Research

Osteoporosis is the most common metabolic bone disease and goes largely undiagnosed throughout the world, due to the inaccessibility of DXA machines. Multivariate analyses of serum bone turnover markers were evaluated in 226 Orange County, California, residents with the intent to determine if serum osteocalcin and serum pyridinoline cross-links could be used to detect the onset of osteoporosis as effectively as a DXA scan. Descriptive analyses of the demographic and lab characteristics of the participants were performed through frequency, means and standard deviation estimations. We implemented logistic regression modeling to find the best classification algorithm for osteoporosis. All calculations and …

Comparative Analysis Of Body Composition And Reference Values Of Visceral Adipose Tissues In Various American Collegiate Sports, Eshan M. Dandekar

Master's Theses

Background: Currently, body composition (BC) assessment is usually performed to diagnose disease states and accurately estimate certain types of tissues. In athletes, performing BC assessments helps gauge training and nutrition programs to see if they are adequately meeting the athlete’s needs to improve performance. Annual Dual Energy X-ray Absorptiometry (DXA) scans before the start of an athlete’s season can help identify an athlete’s preparedness or health before training begins.

Objective: To assess the preseason BC of four collegiate sports: Men’s basketball, men’s baseball, women’s volleyball, and women’s soccer, for Fat Mass (FM), bone mineral density BMD), Fat-Free Mass …

Unfolded Protein Response Pathways In Skeletal Muscle Homeostasis., Kyle R. Bohnert

Electronic Theses and Dissertations

Skeletal muscle mass, contractile properties, and metabolic function are regulated through the coordinated activation of multiple intracellular signaling pathways and genetic reprogramming. The endoplasmic reticulum (ER) plays a pivotal role in protein folding and calcium homeostasis in many cell types, including skeletal muscle. Disruption of calcium levels or accumulation of misfolded proteins in the ER lumen leads to stress, which results in the activation of a signaling network called the unfolded protein response (UPR). Further, recent studies have suggested that in certain conditions, UPR pathways can be activated independent of ER stress. However, the role of ER stress and the …

A Biomechanical Simulation Of Musculoskeletal Kinematics During Ambulation, Alex Thomas

Master's Theses (2009 -)

The purpose of this study was to validate a 3D musculoskeletal model in OpenSim and assess OpenSim’s ability to determine muscle-length variation during ambulation. An 18 camera motion capture system was used to analyze 20 healthy individuals between the ages of 18 and 35. Following data collection, the data was processed through OpenSim and Visual3D. The kinematic output processed through the OpenSim model was then compared to the kinematic output of the validated Visual3D model to validate the OpenSim model. Muscle fiber length data obtained from the same experimental data was compared to control data to assess OpenSim’s muscle analysis …

Glucosamine From Hydrolysis Of 3d Printing Chitosan For Osteoarthritis Treatment, Ruj Dansriboon, Laphon Premcharoen

The International Student Science Fair 2018

This project aims to introduce a new way for osteoarthritis treatment which is expected to increase in the future. Glucosamine is the main subject for a treatment, which can be derived by hydrolyzing chitosan. This project also includes extraction of chitosan from shrimp waste to make a worthy use of food waste from industry. In this project, 3D printer is applied to print chitosan gel since 3D printing is adjustable to form various shapes of the gel.

The research process begins with the extraction of chitosan from shrimp shells. For the next step, the percent of deacetylation of chitosan was …

Immunohistochemical Identification Of Human Skeletal Muscle Macrophages, Kate Kosmac, Bailey D. Peck, R. Grace Walton, Jyothi Mula, Philip A. Kern, Marcas M. Bamman, Richard A. Dennis, Cale A. Jacobs, Christian Lattermann, Darren L. Johnson, Charlotte A. Peterson

Physical Therapy Faculty Publications

Macrophages have well-characterized roles in skeletal muscle repair and regeneration. Relatively little is known regarding the role of resident macrophages in skeletal muscle homeostasis, extracellular matrix remodeling, growth, metabolism and adaptation to various stimuli including exercise and training. Despite speculation into macrophage contributions during these processes, studies characterizing macrophages in non-injured muscle are limited and methods used to identify macrophages vary. A standardized method for the identification of human resident skeletal muscle macrophages will aide in the characterization of these immune cells and allow for the comparison of results across studies. Here, we present an immunohistochemistry (IHC) protocol, validated by …

Transcriptional Profiling Reveals Extraordinary Diversity Among Skeletal Muscle Tissues, Erin E. Terry, Xiping Zhang, Christy Hoffmann, Laura D. Hughes, Scott A. Lewis, Jiajia Li, Matthew J. Wallace, Lance A. Riley, Collin M. Douglas, Miguel A. Gutierrez-Monreal, Nicholas F. Lahens, Ming C. Gong, Francisco H. Andrade, Karyn A. Esser, Michael E. Hughes

Physiology Faculty Publications

Skeletal muscle comprises a family of diverse tissues with highly specialized functions. Many acquired diseases, including HIV and COPD, affect specific muscles while sparing others. Even monogenic muscular dystrophies selectively affect certain muscle groups. These observations suggest that factors intrinsic to muscle tissues influence their resistance to disease. Nevertheless, most studies have not addressed transcriptional diversity among skeletal muscles. Here we use RNAseq to profile mRNA expression in skeletal, smooth, and cardiac muscle tissues from mice and rats. Our data set, MuscleDB, reveals extensive transcriptional diversity, with greater than 50% of transcripts differentially expressed among skeletal muscle tissues. We detect …

Insertion And Presence Of Fine-Wire Intramuscular Electrodes To The Lumbar Paraspinal Muscles Do Not Affect Muscle Performance And Activation During Highexertion Spinal Extension Activities, Szu-Ping Lee, Jo Armour Smith, Matthew Kimber, Kelsey Houk

Physical Therapy Faculty Articles and Research

Background

Low back pain (LBP) is commonly associated with paraspinal muscle dysfunctions. A method to study deep lumbar paraspinal (i.e. multifidus) muscle function and neuromuscular activation pattern is intramuscular electromyography (EMG). Previous studies have shown that the procedure does not significantly impact muscle function during activities involving low-level muscle contractions. However, it is currently unknown how muscular function and activation are affected during high-exertion contractions.

Objective

To examine the effects of insertion and presence of fine-wire EMG electrodes in the lumbar multifidus on muscle strength, endurance, and activation profiles during high-exertion spinal extension muscle contractions.

Design

Single-blinded, repeated measures intervention …

Melatonin-Micronutrients Osteopenia Treatment Study (Mots): A Translational Study Assessing The Effects Of Melatonin, Strontium Citrate, Vitamin D3 And Vitamin K2 On Bone Density, Bone Turnover Markers And Health-Related Quality Of Life In Postmenopausal Osteopenic Women Following A One-Year Double-Blind Randomized Placebo-Controlled Trial And On Osteoblast-Osteoclast Co-Cultures, Sifat Maria

Electronic Theses and Dissertations

Objective: The purpose of this study was to assess if a novel combination of melatonin and three other natural bone-aiding micronutrients: strontium citrate, vitamins D₃ and K₂ (MSDK) could improve bone health by modulating the activity of osteoblasts and osteoclasts in favor of balanced bone remodeling and by improving the overall health-related quality of life in postmenopausal osteopenic women.

Methods: The Melatonin-micronutrients Osteopenia Treatment Study (MOTS) is a translational research study that used both clinical and in vitro approaches to assess the efficacy of MSDK on bone health in women and to identify potential mechanisms for its effects. …

Effects Of Load Carriage And Surface Inclination On Linear And Non-Linear Postural Variability, Rahul Soangra, Hema Bhatt, Ehsan Rashedi

Physical Therapy Faculty Articles and Research

Understanding of inclined-work-related risk of falls and developing novel practical engineering controls for reducing this risk of falls among hilly working population remains in high demand. Standing on sloped surfaces provides a unique environment for examining the biomechanics and neural control of standing. The present investigation examined the variability of postural signals when standing on inclined surfaces and with load carriages by linear and nonlinear analysis. The purpose of this study was to determine if the sloped surface deteriorated in postural stability among healthy individuals with two distinctive kinds of load carriage methods head versus posterior load carriage. We also …

Oncology Section Edge Task Force On Cancer: Measures Of Cancer-Related Fatigue—A Systematic Review, Mary Insana Fisher, Claire Davies, Hannah Lacy, Deborah Doherty

Physical Therapy Faculty Publications

Background: Cancer-related fatigue (CRF) is one of the most common side effects of cancer and cancer treatment. Being able to accurately screen for and assess CRF will improve access to and prescriptions for interventions. Valid and reliable measures to screen for and assess CRF need to be identified.

Purpose: To identify and recommend reliable, valid, and clinically useful tools to screen for and assess CRF among those treated for cancer.

Methods: A systematic review of the literature was conducted to assess the published psychometric properties and clinical feasibility of each method identified. Task force members independently reviewed each measure using …

Mechanisms Of Fatigue With Aging: Evidence From The Whole-Limb To The Single Cell In Humans, Christopher W. Sundberg

Dissertations (1934 -)

Aging is accompanied by a loss of muscle mass and increased fatigability of limb muscles making it difficult for old adults to generate the force and power necessary to perform daily activities, such as ascending a flight of stairs. The mechanisms for the age-related increase in fatigability in old and very old adults (≥80 yrs) and whether there are differences between men and women are unknown. The purpose of this dissertation was to determine the mechanisms for the age-related increase in fatigability in men and women by studying fatigue at the level of the whole-limb and within the muscle cells. …

Gender And Posture Are Significant Risk Factors To Musculoskeletal Symptoms During Touchscreen Tablet Computer Use, Szu-Ping Lee, Ya-Ting Hsu, Betina Bair, Marissa Toberman, Lung-Chang Chien

Physical Therapy Faculty Research

[Purpose] To investigate the prevalence of neck and shoulder symptoms during the use of tablet computer, and to identify the risk factors associated with these symptoms. [Subjects and Methods] A cross-sectional survey was conducted to study tablet computer usage, posture during use, and neck and shoulder symptoms in 412 participants in a school setting. Significant risk factors for musculoskeletal symptoms during tablet computer use were identified. [Results] Overall prevalence of musculoskeletal symptoms during tablet computer use was 67.9% with greater prevalence of neck symptoms (neck: 84.6%; shoulder/upper extremity: 65.4%). Significant risk factors associated with symptoms during use were: current musculoskeletal …

Human Body Composition And Immunity: Visceral Adipose Tissue Produces Il-15 And Muscle Strength Inversely Correlates With Nk Cell Function In Elderly Humans, Ahmad Al-Attar, Steven R. Presnell, Jody L. Clasey, Douglas E. Long, R. Grace Walton, Morgan Sexton, Marlene E. Starr, Philip A. Kern, Charlotte A. Peterson, Charles T. Lutz

Pathology and Laboratory Medicine Faculty Publications

Natural killer (NK) lymphocyte-mediated cytotoxicity and cytokine secretion control infections and cancers, but these crucial activities decline with age. NK cell development, homeostasis, and function require IL-15 and its chaperone, IL-15 receptor alpha (IL-15Rα). Macrophages and dendritic cells (DC) are major sources of these proteins. We had previously postulated that additional IL-15 and IL-15Rα is made by skeletal muscle and adipose tissue. These sources may be important in aging, when IL-15-producing immune cells decline. NK cells circulate through adipose tissue, where they may be exposed to local IL-15. The objectives of this work were to determine (1) if human muscle, …

Cam Impingement In A Collegiate Male Soccer Player With Bilateral Arthroscopic Labral Repair, Nayun Ahn

UNO Student Research and Creative Activity Fair

Cam impingement in a collegiate male soccer player with the bilateral arthroscopic labral repair.

To demonstrate cam impingement and recurrent cam deformity caused by femoroacetabular impingement after bilateral arthroscopic labral repair in a collegiate male soccer player. Cam impingement is caused by deformities of the femoral head. The deformity is generated due to overuse and high shear stress on the femoral head leading to restricted hip ROM by grinding the articular cartilage. It is typically detected in young, active male populations playing high-impact sports. In this case, one NCAA Division 1 soccer midfielder reported the recurrent cam impingement after he …

Venous Thoracic Outlet Syndrome With Paget-Schroetter’S Syndrome In A Male Collegiate Baseball Player, Jaeho Jang

UNO Student Research and Creative Activity Fair

A NCAA Division I baseball middle infielder complained of discomfort in his right upper extremity. He reported no specific mechanism of injury. He had a history of right elbow fracture at age eight with joint displacement. However, no other previous injury to his upper extremity was reported. He did not feel any pain or abnormal sensations while exercising, but noted some discomfort in the right arm, shoulder and pectoral muscles afterward. The evaluating athletic trainer also noted obvious swelling and discoloration of the right arm, bilaterally different temperature, decreased radial pulse, and positive Roo’s and Adson’s Tests. The venous duplex …

In-Home Delivery Of Constraint-Induced Movement Therapy Via Virtual Reality Gaming, Alexandra L. Borstad, Roger Crawfis, Kala Phillips, Linda Pax Lowes, David Maung, Ryan Mcpherson, Amelia Siles, Lise Worthen-Chaudhari, Lynne V. Gauthier

Journal of Patient-Centered Research and Reviews

Purpose: People with chronic hemiparesis are frequently dissatisfied with the recovery of their hand and arm, yet many lack access to effective treatments. Constraint-induced movement therapy (CI therapy) effectively increases arm function and spontaneous use in persons with chronic hemiparesis. The purpose of this study was to determine the feasibility and measure safety and outcomes of an in-home model of delivering CI therapy using a custom, avatar-based virtual reality game.

Methods: Seventeen individuals with chronic hemiparesis participated in this pretest/posttest quasi-experimental design study. The 10-day intervention had three components: 1) high-repetition motor practice using virtual reality gaming; 2) constraint of …

Use Of An Optical Scanning Device To Monitor The Progress Of Noninvasive Treatments For Chest Wall Deformity: A Pilot Study, Robert E. Kelly Jr., Robert J. Obermeyer, Ann Kuhn, Frazier W. Frantz, Mohammad F. Obeid, Nahom Kidane, Frederic D. Mckenzie

Computational Modeling & Simulation Engineering Faculty Publications

Background: The nonsurgical treatment of chest wall deformity by a vacuum bell or external brace is gradual, with correction taking place over months. Monitoring the progress of nonsurgical treatment of chest wall deformity has relied on the ancient methods of measuring the depth of the excavatum and the protrusion of the carinatum. Patients, who are often adolescent, may become discouraged and abandon treatment. Methods: Optical scanning was utilized before and after the intervention to assess the effectiveness of treatment. The device measured the change in chest shape at each visit. In this pilot study, patients were included if they were …

A Comparison Of Hamstring Injury Recovery Rates In Male And Female Athletes, Amanda Hall

Undergraduate Honors Theses

Excerpt from Introduction

Hamstring injuries are among the most common muscular injuries sustained by athletes across multiple levels of various sports (Askling et al). Most hamstring injuries occur during similar movements and under similar conditions, where the muscle is required to be explosive. Thus, athletes that participate in sports where “sprinting, kicking, or high-speed skilled movements” are required, experience an increased likelihood of suffering a hamstring injury (Erickson and Sherry). After injury, athletes are then subjected to different methods of rehabilitation to heal and strengthen the afflicted area. However, some athletes take longer than others to return and impatience may …

Muscle Synergy During A Single Leg Standing Test In Ambulatory Children With Cerebral Palsy, Brennan L. Smith

Theses and Dissertations--Kinesiology and Health Promotion

INTRODUCTION: Cerebral Palsy (CP) is a sensorimotor disorder characterized by dysfunctional motor coordination, balance problems, and loss of selective motor control. Motor coordination exhibited as co-contraction, has been subjectively quantified using gait analysis, but recent studies have begun to objectively analyze the amount of co-contraction by collecting electromyography (EMG) data. Center of pressure excursion (COPE) measurements collected during a single leg standing test (SLST) have shown to be more valid measurements of balance in populations with motor disabilities than a SLST alone. A recent study has correlated increased COPE velocity with a lower fall risk as determined by reported fall …

Using Foot Pressure Analysis To Predict Reoccurrence Of Deformity For Children With Unilateral Clubfoot, Juanita Jean Wallace

Theses and Dissertations--Kinesiology and Health Promotion

Reoccurrence of deformity can affect upwards of 64% of children with clubfoot. The ability to use foot function as a measure of reoccurrence has not been previously assessed. The purpose of this investigation was to utilize foot pressure analysis to predict the probability of reoccurrence in children with unilateral clubfoot. Retrospective foot pressure data revealed predictive algorithms detecting the probability of experiencing any type of reoccurrence (overall reoccurrence) and for experiencing a tibialis anterior tendon transfer (TATT). The equation for overall reoccurrence reported sensitivity and specificity of 0.82 and 0.81 and the equation for TATT reported values of 0.81 and …

Examining Injury Data Reporting Practices Among Wildland Firefighters, Erin M. Boggs

Graduate Student Theses, Dissertations, & Professional Papers

Wildland Firefighter (WLFF) Crews lack an injury surveillance program to collect information on non-traumatic and traumatic injuries. Tactical athletes including: police, military and structural firefighters all have a variety of collection systems in place for injury data collection. The lack of injury data prevents WLFF crews from identifying high-risk environments, implementing injury prevention programs, and improving the overall quality of care on the job. Over the last several decades the recent rise in wildfire occurrences and wildfire suppression costs creates a need for healthy and strong individuals in the field. The cost of firefighter salaries and medical care can be …

Changes In Balance And Joint Position Sense During A 12-Day High Altitude Trek: The British Services Dhaulagiri Medical Research Expedition, Sarah B. Clarke, Kevin Deighton, Caroline Newman, Gareth Nicholson, Liam Gallagher, Christopher J. Boos, Adrian Mellor, David R. Woods, John P. O'Hara

Journal Articles

Postural control and joint position sense are essential for safely undertaking leisure and professional activities, particularly at high altitude. We tested whether exposure to a 12-day trek with a gradual ascent to high altitude impairs postural control and joint position sense. This was a repeated measures observational study of 12 military service personnel (28±4 years). Postural control (sway velocity measured by a portable force platform) during standing balance, a Sharpened Romberg Test and knee joint position sense were measured, in England (113m elevation) and at 3 research camps (3619m, 4600m and 5140m) on a 12-day high altitude trek in the …