Read by QxMD icon Read

Joint loading

Daniel J Southwell, Shane A Petersen, Tyson A C Beach, Ryan B Graham
Altering footwear worn during performance of the barbell back squat has been shown to change motion patterns, but it is not completely understood how this affects biomechanical loading demands. The primary objective was to compare lower back and extremity net joint moments in 24 experienced weightlifters (12M, 12F) who performed 80% one-repetition maximum back squats under three different footwear conditions (barefoot, running shoes, weightlifting shoes). Results showed that there was a significant main effect of footwear condition on the knee extension moment (p=0...
October 12, 2016: Journal of Electromyography and Kinesiology
Vajara Wilairatana, Peerasit Sinlapavilawan, Sittisak Honsawek, Noppachart Limpaphayom
BACKGROUND: The aim was to compare serum levels of interleukin-6 (SIL6), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and joint fluid IL-6 (JIL-6) level between total knee arthroplasty (TKA) that used bone cement (BC group) and antibiotic-loaded bone cement (ALBC group). MATERIALS AND METHODS: Thirty-nine patients (40 TKAs) with a mean age of 69.6 years were non-randomly assigned to the BC or ALBC groups. Samples of SIL6, ESR, and CRP were collected at baseline and at 24 h, 72 h, and 4 weeks after surgery...
October 21, 2016: Journal of Orthopaedics and Traumatology: Official Journal of the Italian Society of Orthopaedics and Traumatology
Jasper Stevens, Kenneth Meijer, Wouter Bijnens, Mathijs C H W Fuchs, Lodewijk W van Rhijn, Joris P S Hermus, Sander van Hoeve, Martijn Poeze, Adhiambo M Witlox
BACKGROUND: Arthrodesis of the first metatarsophalangeal (MTP1) joint is an intervention often used in patients with severe MTP1 joint osteoarthritis and relieves pain in approximately 80% of these patients. The kinematic effects and compensatory mechanism of the foot for restoring a more normal gait pattern after this intervention are unknown. The aim of this study was to clarify this compensatory mechanism, in which it was hypothesized that the hindfoot and forefoot would be responsible for compensation after an arthrodesis of the MTP1 joint...
October 21, 2016: Foot & Ankle International
X Li, M Li, J Lu, Y Hu, L Cui, D Zhang, Y Yang
OBJECTIVES: To elucidate the effects of age on the expression levels of the receptor activator of the nuclear factor-κB ligand (RANKL) and osteoclasts in the periodontal ligament during orthodontic mechanical loading and post-orthodontic retention. MATERIALS AND METHODS: The study included 20 male Sprague-Dawley rats, ten in the young group (aged four to five weeks) and ten in the adult group (aged 18 to 20 weeks). In each rat, the upper-left first molar was subjected to a seven-day orthodontic force loading followed by a seven-day retention period...
October 2016: Bone & Joint Research
Michael P Atkinson, Moshe Kress, Roberto Szechtman
BACKGROUND: The US invests considerable effort in searching and interdicting drug-trafficking vessels in the Caribbean and Eastern Pacific regions. While some vessels are indeed interdicted, resulting in confiscation of substantial quantities of drugs, many such vessels manage to avoid detection and arrive safely at their destinations in Central America and Mexico with their drug load intact. The agency in charge of interdicting this traffic, Joint Interagency Task Force South-JIATF-S, sends out both aerial and surface assets for search and interdiction missions...
October 18, 2016: International Journal on Drug Policy
Lindsay V Slater, Joseph M Hart
The squat is an assessment of lower extremity alignment during movement, however there is little information regarding altered joint kinetics during poorly performed squats. The purpose of this study was to examine changes in joint kinetics and power from altered knee alignment during a squat. Thirty participants completed squats while displacing the knee medially, anteriorly, and with neutral alignment (control). Sagittal and frontal plane torques at the ankle, knee, and hip were altered in the descending and ascending phase of the squat in both the medial and anterior malaligned squat compared to the control squat...
October 12, 2016: Journal of Electromyography and Kinesiology
Christian Voigt, Andreas Schaller, Carsten Klöhn, Roger Scholz
PURPOSE: In revision total hip arthroplasty, until today, orthopaedic surgeons are missing evidence-based guidelines on cementless acetabular cup fixation. METHODS: 5 finite element models were generated featuring the following anchorage strategies: 1 short peg, 1 long peg, 2 long screws, 3 short screws and zero anchoring components for reference. The micromotions at the implant-bone interface were analyzed for 3 different loadcases, "Seated leg-crossing" (joint force 940 N, impingement force 750 N), "Normal gait" (joint force 1820 N), and "Stumbling" (joint force 4520 N)...
October 15, 2016: Hip International: the Journal of Clinical and Experimental Research on Hip Pathology and Therapy
Hyunglae Lee, Elliott J Rouse, Hermano Igo Krebs
The human ankle joint plays a critical role during walking and understanding the biomechanical factors that govern ankle behavior and provides fundamental insight into normal and pathologically altered gait. Previous researchers have comprehensively studied ankle joint kinetics and kinematics during many biomechanical tasks, including locomotion; however, only recently have researchers been able to quantify how the mechanical impedance of the ankle varies during walking. The mechanical impedance describes the dynamic relationship between the joint position and the joint torque during perturbation, and is often represented in terms of stiffness, damping, and inertia...
2016: IEEE Journal of Translational Engineering in Health and Medicine
Gerrit Bode, Ferdinand Kloos, Matthias J Feucht, Benjamin Fleischer, Norbert Südkamp, Philipp Niemeyer, Christoph Becher
PURPOSE: The unloading effect of an extra-articular absorber system on the knee joint medial compartment was compared with high tibial osteotomy (HTO) under physiological conditions in vitro. METHODS: Seven fresh-frozen cadaveric knees were used to test isokinetic flexion-extension motions under physiological loading using a biomechanical knee simulator. Tibiofemoral area contact and peak contact pressures were measured using pressure-sensitive film in the untreated medial compartment...
October 19, 2016: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
Daniela Ohlendorf, Christina Erbe, Imke Hauck, Jennifer Nowak, Ingo Hermanns, Dirk Ditchen, Rolf Ellegast, David A Groneberg
BACKGROUND: In Germany, about 86.7 % of the dentists have stated to suffer from pain in the neck and shoulder region. These findings are predominantly based on surveys. Therefore the objective of this study is to conduct a kinematic analysis of occupational posture in dentistry. METHODS: Twenty one dentists (11 f/10 m; age: 40.1 ± 10.4 years) have participated in this examination. The CUELA-System was used to collect kinematic data of the activities on an average dental workday...
October 18, 2016: BMC Musculoskeletal Disorders
Jonathan T Kaplan, Corey P Neu, Hicham Drissi, Nancy C Emery, David M Pierce
Osteoarthritis and articular cartilage injuries are common conditions in human joints and a frequent cause of pain and disability. Unfortunately, cartilage is avascular and has limited capabilities for self-repair. Despite the societal impact, there is little information on the dynamic process of cartilage degeneration. We performed a series of cyclic unconfined compression tests motivated by in vivo loading conditions and designed to generate mechanical fatigue. We examined the functional (both stress-stretch and creep) responses of the tissue after recovery from a specified number of loading cycles, as well as histology and second harmonic generation microscopy images...
October 1, 2016: Journal of the Mechanical Behavior of Biomedical Materials
Meagan E Ita, Nathan D Crosby, Ben A Bulka, Beth A Winkelstein
STUDY DESIGN: Immunohistochemistry labeled pre- and post-synaptic structural markers to quantify excitatory and inhibitory synapses in the spinal superficial dorsal horn at 14 days after painful facet joint injury in the rat. OBJECTIVE: The objective of this study was to investigate the relationship between pain and synapse density in the spinal cord after facet injury. SUMMARY OF BACKGROUND DATA: Neck pain is a major contributor to disability and often becomes chronic...
October 17, 2016: Spine
Teresa E Flaxman, Tine Alkjær, Erik B Simonsen, Michael R Krogsgaard, Daniel L Benoit
INTRODUCTION: Knee muscles are commonly labelled as flexors or extensors and aptly stabilize the knee against sagittal plane loads. However, how these muscles stabilize the knee against adduction-abduction and rotational loads remains unclear. Our study sought to: (1) classify muscle roles as they relate to joint stability by quantifying the relationship between individual muscle activation patterns and internal net joint moments in all three loading planes, and (2) determine if these roles change with increasing force levels...
October 14, 2016: Medicine and Science in Sports and Exercise
John Morellato, Hakim Louati, Andrew Bodrogi, Andrew Stewart, Steven Papp, Allan Liew, Wade Gofton
BACKGROUND/PURPOSE: There have been no studies assessing the optimal biomechanical tension of suture button constructs. The purpose of this study was to assess optimal tensioning of suture button fixation and its ability to maintain reduction under loaded conditions using a stress computed tomography (CT) model. METHODS: Ten cadaveric lower limbs disarticulated at the knee were used. The limbs were placed in a modified ankle load frame that allowed for the application of sustained torsional axial, or combined torsional/axial loads...
October 13, 2016: Journal of Orthopaedic Trauma
Bhupinder Singh, Huy Vo, Shelby L Francis, Kathleen F Janz, John H Yack
PURPOSE: This study assessed the biomechanical gait changes in obese and normal weight female adult subjects following a commonly recommended 30-minute walking session. Hip and knee adduction and extensor moments, which are the primary modulators of frontal and sagittal plane load distribution were hypothesized to increase in obese females following a 30-minute walking period, resulting in more stress across the hip and knee joint. METHODS: Ten obese (37.7 ± 4...
October 6, 2016: Medicine and Science in Sports and Exercise
Sakiko Oyama, Andrew G Waldhelm, Araceli R Sosa, Ravina R Patel, Derick L Kalinowski
OBJECTIVE: Pitching technique is one of many factors that affect injury risk. Exhibiting excessive contralateral trunk tilt (CLT) during pitching has been linked to higher ball speed but also to increased joint loading. Deficit in trunk muscle strength has been suggested as an underlying cause of this movement pattern. The purpose of the study was to compare trunk muscle strength between youth baseball pitchers with varying degree of CLT during pitching. DESIGN: Cross-sectional study...
October 6, 2016: Clinical Journal of Sport Medicine: Official Journal of the Canadian Academy of Sport Medicine
Michelle Rae, Michelle Girouard, Colin McKinnon, Jack P Callaghan, Wayne J Albert
Police officers have been identified as group at high risk for developing musculoskeletal injuries. The purpose of this study was to determine physical demands differences of patrol officers during day shifts and night shifts. Sixteen participants were recruited (10 males, 6 females) for in-vehicle observation over one full day shift and one full night shift. Dynamic pressure distribution when seated in the vehicle was assessed and compared between the first and last part of each shift. Activity characterization and postural analyses were conducted from video that was recorded continuously for the duration of each shift to determine time spent in each task and corresponding postures...
October 18, 2016: International Journal of Occupational Safety and Ergonomics: JOSE
Iris K Minichmayr, André Schaeftlein, Joseph L Kuti, Markus Zeitlinger, Charlotte Kloft
OBJECTIVES: We aimed to assess linezolid pharmacokinetics in the plasma and interstitial space fluid (ISF) of patients with sepsis, diabetic foot infections or cystic fibrosis and healthy volunteers. The impacts of joint characteristics and disease on plasma and target-site exposure were to be identified together with the benefit of dose intensification in critically ill patients. METHODS: Rich plasma (n = 1598) and ISF concentrations in subcutaneous adipose (n = 1430) and muscle tissue (n = 1089) measured by microdialysis were pooled from three clinical trials with 51 individuals receiving 600 mg of intravenous and oral linezolid...
October 17, 2016: Clinical Pharmacokinetics
Kun Zhang, Yanxi Chen, Minfei Qiang, Yini Hao
Single, double, and triple hindfoot arthrodeses are used to correct hindfoot deformities and relieve chronic pain. However, joint fusion may lead to dysfunction in adjacent articular surfaces. We compared range of motion in adjacent joints before and after arthrodesis to determine the effects of each procedure on joint motion. The theory of moment of couple, bending moment and balanced loading was applied to each of 16 fresh cadaver feet to induce dorsiflexion, plantarflexion, internal rotation, external rotation, inversion, and eversion...
October 18, 2016: Scientific Reports
Elizabeth Wellsandt, Ashutosh Khandha, Kurt Manal, Michael J Axe, Thomas S Buchanan, Lynn Snyder-Mackler
Anterior cruciate ligament (ACL) injury results in altered knee joint mechanics which frequently continue even after ACL reconstruction. The persistence of altered mechanical loading of the knee is of concern due to its likely role in the development of post-traumatic osteoarthritis (OA). Joint contact forces are associated with post-traumatic OA development, but evaluation of factors influencing the magnitude of contact forces after ACL injury is needed to advance current strategies aimed at preventing post-traumatic OA...
October 17, 2016: Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"