Science.gov

Sample records for shoulder joint forces

  1. Glenohumeral joint reaction forces increase with critical shoulder angles representative of osteoarthritis-A biomechanical analysis.

    PubMed

    Viehöfer, Arnd F; Snedeker, Jess G; Baumgartner, Daniel; Gerber, Christian

    2016-06-01

    Osteoarthritis (OA) of the glenohumeral joint constitutes the most frequent indication for nontraumatic shoulder joint replacement. Recently, a small critical shoulder angle (CSA) was found to be associated with a high prevalence of OA. This study aims to verify the hypothesis that a small CSA leads to higher glenohumeral joint reaction forces during activities of daily living than a normal CSA. A shoulder simulator with simulated deltoid (DLT), supraspinatus (SSP), infraspinatus/teres minor (ISP/TM), and subscapularis (SSC) musculotendinous units was constructed. The DLT wrapping on the humerus was simulated using a pulley that could be horizontally adjusted to simulate the 28° CSA found in OA or the 33° CSA found in disease-free shoulders. Over a range of motion between 6° and 82° of thoracohumeral abduction joint forces were measured using a six-axis load cell. An OA-associated CSA yielded higher net joint reaction forces than a normal CSA over the entire range of motion. The maximum difference of 26.4 N (8.5%) was found at 55° of thoracohumeral abduction. Our model thus suggests that a CSA typical for OA predisposes the glenohumeral joint to higher joint reaction forces and could plausibly play a role in joint overloading and development of OA. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1047-1052, 2016.

  2. Shoulder Joint For Protective Suit

    NASA Technical Reports Server (NTRS)

    Kosmo, Joseph J.; Smallcombe, Richard D.

    1994-01-01

    Shoulder joint allows full range of natural motion: wearer senses little or no resisting force or torque. Developed for space suit, joint offers advantages in protective garments for underwater work, firefighting, or cleanup of hazardous materials.

  3. Shoulder Joint Replacement

    MedlinePlus

    ... examination. This will assess shoulder motion, stability, and strength. joint. (Right) Osteoarthritis of the shoulder. Note the ... you can start moving sooner and get your strength back more quickly. Talk with your surgeon if ...

  4. 21 CFR 888.3690 - Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint humeral (hemi-shoulder) metallic... Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis. (a) Identification. A shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis is a device made of alloys, such as...

  5. 21 CFR 888.3680 - Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint glenoid (hemi-shoulder) metallic... Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis. (a) Identification. A shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis is a device that has a glenoid (socket)...

  6. Ultrasonography of the canine shoulder joint and its pathological changes.

    PubMed

    Piórek, A; Adamiak, Z

    2010-01-01

    The objective of this study was to present and discuss the available data on canine shoulder joint ultrasonography. The paper presents the method of ultrasonographic examination of the shoulder joint area, describes the normal structure of the shoulder joint in dogs, and discusses the most frequently encountered shoulder joint pathologies.

  7. Problems With Large Joints: Shoulder Conditions.

    PubMed

    Campbell, Michael

    2016-07-01

    The shoulder is the most mobile joint in the body. It requires an extensive support system to create mobility while providing stability. Although there are many etiologies of shoulder pain, weakness, and instability, most injuries in the shoulder are due to overuse. Rotator cuff tears, labral tears, calcific tendinopathy, and impingement often result from chronic overuse injuries. Acute injuries include dislocations that can cause labral tears or other complications. Frozen shoulder refers to a typically benign condition of restricted range of motion that may spontaneously resolve but can cause prolonged pain and discomfort. The history combined with specific shoulder examination techniques can help family physicians successfully diagnose shoulder conditions. X-ray imaging typically is sufficient to rule out more serious etiologies when evaluating patients with shoulder conditions. However, imaging with magnetic resonance imaging (MRI) study or ultrasonography for rotator cuff tears, and MRI study with intra-articular contrast for labral tears, is needed to confirm these diagnoses. Corticosteroid injections and physical therapy are first-line treatments for most shoulder conditions. Surgical options typically are reserved for patients for whom conservative treatments are ineffective, and typically are performed arthroscopically.

  8. 21 CFR 888.3690 - Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... uncemented prosthesis. 888.3690 Section 888.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis. (a) Identification. A shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis is a device made of alloys, such as...

  9. 21 CFR 888.3680 - Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... cemented prosthesis. 888.3680 Section 888.3680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis. (a) Identification. A shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis is a device that has a glenoid (socket)...

  10. 21 CFR 888.3690 - Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... uncemented prosthesis. 888.3690 Section 888.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis. (a) Identification. A shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis is a device made of alloys, such as...

  11. 21 CFR 888.3690 - Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... uncemented prosthesis. 888.3690 Section 888.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis. (a) Identification. A shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis is a device made of alloys, such as...

  12. 21 CFR 888.3690 - Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... uncemented prosthesis. 888.3690 Section 888.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis. (a) Identification. A shoulder joint humeral (hemi-shoulder) metallic uncemented prosthesis is a device made of alloys, such as...

  13. 21 CFR 888.3680 - Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... cemented prosthesis. 888.3680 Section 888.3680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis. (a) Identification. A shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis is a device that has a glenoid (socket)...

  14. Shoulder acromioclavicular joint reconstruction options and outcomes.

    PubMed

    Lee, Simon; Bedi, Asheesh

    2016-12-01

    Acromioclavicular joint separations are a common cause of shoulder pain in the young athletic population. In high-grade injuries, acromioclavicular joint reconstruction procedures may be indicated for functional improvement. There is currently no gold standard for the surgical management of these injuries. Multiple reconstructive options exist, including coracoclavicular screws, hook plates, endobutton coracoclavicular fixations, and anatomic ligament reconstructions with tendon grafts. This article aims to review pertinent acromioclavicular joint anatomy and biomechanics, radiographic evaluation, classification system, as well as reconstruction options, outcomes, and complications.

  15. 21 CFR 888.3680 - Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... made of alloys, such as cobalt-chromium-molybdenum, or alloys with ultra-high molecular weight... equivalent to a shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis that was in...

  16. 21 CFR 888.3680 - Shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... made of alloys, such as cobalt-chromium-molybdenum, or alloys with ultra-high molecular weight... equivalent to a shoulder joint glenoid (hemi-shoulder) metallic cemented prosthesis that was in...

  17. Echographic and Kinetic Changes in the Shoulder Joint after Manual Wheelchair Propulsion Under Two Different Workload Settings

    PubMed Central

    Gil-Agudo, Ángel; Solís-Mozos, Marta; Crespo-Ruiz, Beatriz; del-Ama Eng, Antonio J.; Pérez-Rizo, Enrique; Segura-Fragoso, Antonio; Jiménez-Díaz, Fernando

    2014-01-01

    Manual wheelchair users with spinal cord injury (SCI) have a high prevalence of shoulder pain due to the use of the upper extremity for independent mobility, transfers, and other activities of daily living. Indeed, shoulder pain dramatically affects quality of life of these individuals. There is limited evidence obtained through radiographic techniques of a relationship between the forces acting on the shoulder during different propulsion conditions and shoulder pathologies. Today, ultrasound is widely accepted as a precise tool in diagnosis, displaying particularly effectiveness in screening the shoulder rotator cuff. Thus, we set out to perform an ultrasound-based study of the acute changes to the shoulder soft tissues after propelling a manual wheelchair in two workload settings. Shoulder joint kinetics was recorded from 14 manual wheelchair users with SCI while they performed high- and low-intensity wheelchair propulsion tests (constant and incremental). Shoulder joint forces and moments were obtained from inverse dynamic methods, and ultrasound screening of the shoulder was performed before and immediately after the test. Kinetic changes were more relevant after the most intensive task, showing the significance of high-intensity activity, yet no differences were found in ultrasound-related parameters before and after each propulsion task. It therefore appears that further studies will be needed to collect clinical data and correlate data regarding shoulder pain with both ultrasound images and data from shoulder kinetics. PMID:25566539

  18. Echographic and kinetic changes in the shoulder joint after manual wheelchair propulsion under two different workload settings.

    PubMed

    Gil-Agudo, Ángel; Solís-Mozos, Marta; Crespo-Ruiz, Beatriz; Del-Ama Eng, Antonio J; Pérez-Rizo, Enrique; Segura-Fragoso, Antonio; Jiménez-Díaz, Fernando

    2014-01-01

    Manual wheelchair users with spinal cord injury (SCI) have a high prevalence of shoulder pain due to the use of the upper extremity for independent mobility, transfers, and other activities of daily living. Indeed, shoulder pain dramatically affects quality of life of these individuals. There is limited evidence obtained through radiographic techniques of a relationship between the forces acting on the shoulder during different propulsion conditions and shoulder pathologies. Today, ultrasound is widely accepted as a precise tool in diagnosis, displaying particularly effectiveness in screening the shoulder rotator cuff. Thus, we set out to perform an ultrasound-based study of the acute changes to the shoulder soft tissues after propelling a manual wheelchair in two workload settings. Shoulder joint kinetics was recorded from 14 manual wheelchair users with SCI while they performed high- and low-intensity wheelchair propulsion tests (constant and incremental). Shoulder joint forces and moments were obtained from inverse dynamic methods, and ultrasound screening of the shoulder was performed before and immediately after the test. Kinetic changes were more relevant after the most intensive task, showing the significance of high-intensity activity, yet no differences were found in ultrasound-related parameters before and after each propulsion task. It therefore appears that further studies will be needed to collect clinical data and correlate data regarding shoulder pain with both ultrasound images and data from shoulder kinetics.

  19. 21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace...

  20. 21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  1. 21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace...

  2. 21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  3. 21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace...

  4. 21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  5. 21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace...

  6. 21 CFR 888.3650 - Shoulder joint metal/polymer non-constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Shoulder joint metal/polymer non-constrained... Shoulder joint metal/polymer non-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer non-constrained cemented prosthesis is a device intended to be implanted to replace...

  7. 21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  8. 21 CFR 888.3660 - Shoulder joint metal/polymer semi-constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer semi-constrained... Shoulder joint metal/polymer semi-constrained cemented prosthesis. (a) Identification. A shoulder joint metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace...

  9. Shoulder joint kinetics of the elite wheelchair tennis serve

    PubMed Central

    Reid, Machar; Elliott, Bruce; Alderson, Jacque

    2007-01-01

    Background The shoulder is a key joint in wheelchair locomotion and commonly implicated in injury among virtually all wheelchair populations. In tennis, quantification of the shoulder joint kinetics that characterise the wheelchair serve could enhance injury prevention and rehabilitation practices as well as assist coaches evaluate the efficacy of their current technical instruction. Methods A 12‐camera, 250 Hz Vicon motion analysis system (Oxford Metrics Inc., UK) recorded the 3D flat (WFS) and kick serve (WKS) motions of two male top 30‐ranked international wheelchair players. Mechanical comparisons between wheelchair players, as well as to the previously captured data of 12 high‐performance able‐bodied players executing the same types of serves, were undertaken. Results Without the benefit of a propulsive leg action, wheelchair players developed lower peak absolute (∼32 m/s) and horizontal (∼28 m/s) pre‐impact racquet velocities than able‐bodied players (∼42 m/s, ∼38 m/s). Wheelchair serve tactics nevertheless necessitated that higher pre‐impact horizontal and right lateral racquet velocities characterised the WFS (∼29 m/s, WKS: ∼26 m/s) and WKS (∼4 m/s, WFS: ∼11 m/s) respectively. The shoulder joint kinetics that contributed to the differential racquet velocity profiles were mostly developed independent of wheelchair serve type, but varied with and were likely related to the level and severity of spinal cord injury of the individual players. Conclusions Compared with able‐bodied players, wheelchair players experienced matching pre‐ and post‐impact shoulder joint loads, such that wheelchair and able‐bodied playing populations appear subject to similar shoulder joint injury risk. PMID:17957009

  10. Kinesio Tape and Shoulder-Joint Position Sense

    PubMed Central

    Aarseth, Lindsay M.; Suprak, David N.; Chalmers, Gordon R.; Lyon, Lonnie; Dahlquist, Dylan T.

    2015-01-01

    Context Joint position sense (JPS) is a key neuromuscular factor for developing and maintaining control of muscles around a joint. It is important when performing specialized tasks, especially at the shoulder. No researchers have studied how Kinesio Tape (KT) application affects JPS. Objective To investigate the effects of KT application and no tape on shoulder JPS at increasing shoulder elevations in athletes. Design Cross-sectional study. Setting University laboratory. Patients or Other Participants A total of 27 healthy athletes who did not participate in overhead sports (age = 20.44 ± 1.05 years, height = 175.02 ± 11.67 cm, mass = 70.74 ± 9.65 kg) with no previous pathologic shoulder conditions volunteered for the study. All participants were from 1 university. Intervention(s) Shoulder JPS was assessed at increasing elevations with and without KT application. Participants attempted to actively replicate 3 target positions with and without the KT and without visual guidance. Main Outcome Measure(s) We examined absolute and variable repositioning errors at increasing shoulder-elevation levels with and without KT application. Results Data revealed an interaction between tape and position for absolute error (F2,52 = 4.07, P = .02); simple effects revealed an increase in error, with KT demonstrating a 2.65° increase in error at 90° of elevation compared with no tape (t26 = 2.65, P = .01). The effect size was medium (ω2 = .135). Variable error showed no interaction of tape and position (F2,52 = .709, P = .50). Further analysis of simple effects was not needed. However, we still calculated the effect size and observed small effect sizes for tape (ω2 = .002), position (ω2 = .072), and tape by position (ω2 = .027). Conclusions At 90° of elevation, shoulder JPS was impaired by the application of KT. PMID:26090707

  11. The effect of an active vibration stimulus according to different shoulder joint angles on functional reach and stability of the shoulder joint

    PubMed Central

    Kim, Eun-Kyung; Kim, Seong-Gil

    2016-01-01

    [Purpose] The purpose of this study was to analyze the effect of an active vibration stimulus exercise according to shoulder joint angles on functional reach and stability of the shoulder joint. [Subjects and Methods] Thirty healthy male students participated in this study. Upper limb length of each subject was measured to obtain normalized measurement values. The exercise groups were as follows: group I (n=10, shoulder joint angle of 90°), group II (n=10, shoulder joint angle of 130°), and group III (n=10, shoulder joint angle of 180°). After warm-up, an active vibration stimulus was applied to the subjects with a Flexi-Bar. The Functional Reach Test and Y-balance test were conducted for measurement of shoulder stability. [Results] Analysis of covariance was conducted with values before the intervention as covariates to analyze the differences among the groups in the two tests. There were significant differences among the groups. According to Bonferroni post hoc comparison, group I showed greater improvement than group III in the Functional Reach Test, and group II showed greater improvement than group I and group III in the Y-balance test. [Conclusion] The effect of the exercise with different shoulder joint angles revealed that the shoulder joint has a certain effective joint angle for its functionality and stability. In addition, application of an active vibration stimulus with a Flexi-Bar can be a very effective tool for improvement of functionality and stability of the shoulder joint. PMID:27134352

  12. Joint Forces Capabilities

    DTIC Science & Technology

    2007-11-02

    for countering the proliferation of weapons of mass destruction (WMD) in space. The Space Operations Center ( SPOC ), USSPACECOM is the single point...of contact for assessing space capabilities. Combatant commanders, subordinate JFCs, and Services can access this information from the SPOC via the...special operations forces SPOC Space Operations Center SSBN fleet ballistic missile submarine SST space support team UJTL Universal Joint Task List UN

  13. The shoulder and elbow joints and right and left sides demonstrate similar joint position sense.

    PubMed

    King, Jacqlyn; Harding, Elizabeth; Karduna, Andrew

    2013-01-01

    Proper orientation of the shoulder and elbow is necessary for accurate and precise positioning of the hand. The authors' goal was to compare these joints with an active joint position sense task, while also taking into account the effects of joint flexion angle and arm dominance. Fifteen healthy subjects were asked to replicate presented joint angles with a single degree of freedom active positioning protocol. There were no significant differences in angular joint position sense errors with respect to joint (shoulder vs. elbow) and side (left vs. right). However, when considering linear positioning, errors were lower for the elbow, due to a shorter lever arm. Also, as flexion angles increased toward 90°, there was a consistent pattern of lower errors for both joints.

  14. Clinical Effectiveness of Scapulothoracic Joint Control Training Exercises on Shoulder Joint Dysfunction.

    PubMed

    Zhang, Ming; Zhou, Jing-Jie; Zhang, Yu-Ming; Wang, Ji-Hong; Zhang, Qiu-Yang; Chen, Wei

    2015-05-01

    The objective of this study was to examine the clinical effectiveness of scapulothoracic joint control training exercises on shoulder joint dysfunction. Forty patients with traumatic shoulder pain and joint dysfunction were randomized into the treatment or control group. Standard rehabilitation interventions included glenohumeral joint mobilization techniques, ultrasound therapy, traditional Chinese medicine, interference current therapy, and other comprehensive interventions. Patients received scapulothoracic joint control training exercises, including active and passive motions of the scapulothoracic joints, peri-joint muscle exercise, and joint stability exercises for 1 month. Patient status was evaluated by Constant-Murley scales before and after the prescribed interventions. The pain conditions, daily activities, range of movement, strength tests and total scores were significantly improved compared to prior treatment. Moreover, improvements in pain, daily activities, scope of activities, and total scores for patients in the treatment group were statistically significant when compared to the control group (P < 0.05). However, there was no inter-group difference in strength testing. The combination of standard rehabilitation interventions and scapulothoracic joint control training exercises are an effective treatment of the shoulder joint dysfunction. Moreover, the pain outcomes, scope of activities, and total scores were better in the treatment group.

  15. Shoulder sensorimotor control assessment by force platform: feasibility and reliability.

    PubMed

    Edouard, Pascal; Gasq, David; Calmels, Paul; Ducrot, Sarah; Degache, Francis

    2012-09-01

    Given the important role of the shoulder sensorimotor system in shoulder stability, its assessment appears of interest. Force platform monitoring of centre of pressure (CoP) in upper-limb weight-bearing positions is of interest as it allows integration of all aspects of shoulder sensorimotor control. This study aimed to determine the feasibility and reliability of shoulder sensorimotor control assessment by force platform. Forty-five healthy subjects performed two sessions of CoP measurement using Win-Posturo(®) Medicapteurs force platform in an upper-limb weight-bearing position with the lower limbs resting on a table to either the anterior superior iliac spines (P1) or upper patellar poles (P2). Four different conditions were tested in each position in random order: eyes open or eyes closed with trunk supported by both hands and eyes open with trunk supported on the dominant or non-dominant side. P1 reliability values were globally moderate to high for CoP length, CoP velocity and CoP standard deviation (SD), standard error of measurement ranged from 6·0% to 26·5%, except for CoP area. P2 reliability values were globally low and not clinically acceptable. Our results suggest that shoulder sensorimotor control assessment by force platform is feasible and has good reliability in upper-limb weight-bearing positions when the lower limbs are resting on a table to the anterior superior iliac spines. CoP length, CoP velocity and CoP SD velocity appear to be the most reliable variables.

  16. Towards computer-assisted surgery in shoulder joint replacement

    NASA Astrophysics Data System (ADS)

    Valstar, Edward R.; Botha, Charl P.; van der Glas, Marjolein; Rozing, Piet M.; van der Helm, Frans C. T.; Post, Frits H.; Vossepoel, Albert M.

    A research programme that aims to improve the state of the art in shoulder joint replacement surgery has been initiated at the Delft University of Technology. Development of improved endoprostheses for the upper extremities (DIPEX), as this effort is called, is a clinically driven multidisciplinary programme consisting of many contributory aspects. A part of this research programme focuses on the pre-operative planning and per-operative guidance issues. The ultimate goal of this part of the DIPEX project is to create a surgical support infrastructure that can be used to predict the optimal surgical protocol and can assist with the selection of the most suitable endoprosthesis for a particular patient. In the pre-operative planning phase, advanced biomechanical models of the endoprosthesis fixation and the musculo-skeletal system of the shoulder will be incorporated, which are adjusted to the individual's morphology. Subsequently, the support infrastructure must assist the surgeon during the operation in executing his surgical plan. In the per-operative phase, the chosen optimal position of the endoprosthesis can be realised using camera-assisted tools or mechanical guidance tools. In this article, the pathway towards the desired surgical support infrastructure is described. Furthermore, we discuss the pre-operative planning phase and the per-operative guidance phase, the initial work performed, and finally, possible approaches for improving prosthesis placement.

  17. Shoulder and hip joint for hard space suits

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.

    1986-01-01

    Shoulder and hip joints for hard space suits are disclosed which are comprised of three serially connected truncated spherical sections, the ends of which converge. Ball bearings between the sections permit relative rotation. The proximal end of the first section is connected to the torso covering by a ball bearing and the distal end of the outermost section is connected to the elbow or thigh covering by a ball bearing. The sections are equi-angular and this alleviates lockup, the condition where the distal end of the joint leaves the plane in which the user is attempting to flex. The axes of rotation of the bearings and the bearing mid planes are arranged to intersect in a particular manner that provides the joint with a minimum envelope. In one embodiment, the races of the bearing between the innermost section and the second section is partially within the inner race of the bearing between the torso and the innermost spherical section further to reduce bulk.

  18. 21 CFR 888.3640 - Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Shoulder joint metal/metal or metal/polymer... § 888.3640 Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis. (a) Identification. A shoulder joint metal/metal or metal/polymer constrained cemented prosthesis is a...

  19. 21 CFR 888.3640 - Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Shoulder joint metal/metal or metal/polymer... § 888.3640 Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis. (a) Identification. A shoulder joint metal/metal or metal/polymer constrained cemented prosthesis is a...

  20. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  1. 21 CFR 888.3640 - Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Shoulder joint metal/metal or metal/polymer... § 888.3640 Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis. (a) Identification. A shoulder joint metal/metal or metal/polymer constrained cemented prosthesis is a...

  2. 21 CFR 888.3640 - Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Shoulder joint metal/metal or metal/polymer... § 888.3640 Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis. (a) Identification. A shoulder joint metal/metal or metal/polymer constrained cemented prosthesis is a...

  3. 21 CFR 888.3640 - Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Shoulder joint metal/metal or metal/polymer... § 888.3640 Shoulder joint metal/metal or metal/polymer constrained cemented prosthesis. (a) Identification. A shoulder joint metal/metal or metal/polymer constrained cemented prosthesis is a...

  4. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  5. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  6. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  7. 21 CFR 888.3670 - Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Shoulder joint metal/polymer/metal nonconstrained... ORTHOPEDIC DEVICES Prosthetic Devices § 888.3670 Shoulder joint metal/polymer/metal nonconstrained or semi-constrained porous-coated uncemented prosthesis. (a) Identification. A shoulder joint...

  8. Role of Subscapularis Repair on Muscle Force Requirements with Reverse Shoulder Arthroplasty.

    PubMed

    Hansen, Matthew L; Nayak, Aniruddh; Narayanan, Madusudanan Sathia; Worhacz, Kellen; Stowell, Richard; Jacofsky, Marc C; Roche, Christopher P

    2015-12-01

    Concomitant repair of the subscapularis with reverse shoulder arthroplasty (rTSA) is controversial. To evaluate the biomechanical impact of subscapularis repair with rTSA, a cadaveric shoulder controller quantified the muscle forces required to elevate the arm during scapular abduction with the elbow flexed at 90°. The results of this study demonstrate that concomitant subscapularis repair with rTSA creates a biomechanically unfavorable condition during arm elevation. Specifically, repair of the subscapularis significantly increased the force required by the deltoid and posterior rotator cuff and also significantly increased the joint reaction force relative to when the subscapularis was not repaired. These results also demonstrated that both the 42 mm Grammont and 42 mm Equinoxe® rTSA prostheses significantly decreased the mean force required by the posterior rotator cuff and also significantly decreased the mean joint reaction force over the range of motion relative to the native joint with a rotator cuff tear (supraspinatus). As the posterior rotator cuff is often compromised in patients undergoing rTSA, patients may not be able to sustain these elevated forces in the infraspinatus and teres minor required to counteract the adduction and internal rotation moments generated by the subscapularis during activities of daily living. Similarly, the elevated posterior deltoid force and joint reaction loads could be deleterious to the long-term life of the prosthesis and can also increase the risk of loosening and fractures. For all these reasons, rTSA functional outcomes may be compromised if the subscapularis is repaired.

  9. Dislocated shoulder - aftercare

    MedlinePlus

    ... aftercare; Shoulder subluxation - aftercare; Shoulder reduction - aftercare; Glenohumeral joint dislocation ... that connect bone to bone) of the shoulder joint. All of these tissues help keep your arm ...

  10. ULTRASOUND MEASUREMENTS AND OBJECTIVE FORCES OF GLENOHUMERAL TRANSLATIONS DURING SHOULDER ACCESSORY PASSIVE MOTION TESTING IN HEALTHY INDIVIDUALS

    PubMed Central

    Worst, Haley; Decarreau, Ryan; Davies, George

    2016-01-01

    Background Clinical examination of caspuloligamentous structures of the glenohumeral joint has historically been subjective in nature, as demonstrated by limited intra-rater and inter-rater reproducibility. Musculoskeletal diagnostic ultrasound was utilized to develop a clinically objective measurement technique for glenohumeral inferior and posterolateral translation. Purpose The purpose of this study was to measure the accessory passive force required to achieve end range glenohumeral posterolateral and inferior accessory translation, as well as, to quantify the amount of translation of the glenohumeral joint caused by the applied force. Study Design Cross-sectional descriptive correlational study Methods Twenty-five asymptomatic subjects between the ages of 18 and 30 were recruited via convenience sampling. Posterolateral and inferior shoulder accessory passive translation was assessed and measured using a GE LOGIQe ultrasound, while concurrently using a hand held dynamometer to quantify the passive force applied during assessment. Normative values for force and translation were described as means and standard deviations. Results Mean values for posterolateral translation were 6.5 +/− 4.0 mm on the right shoulder and 6.3 +/− 3.5 mm on the left with an associated mean force of 127.1 +/− 55.6 N and 114.4 +/− 50.7 N, respectively. Mean values for inferior translation were 4.8 +/− 1.7 mm on the right shoulder and 5.4 +/− 1.8 mm on the left with an associated mean force of 84.5 +/− 30.5 N and 76.1 +/− 30.1 N, respectively. There was a significant association between inferior translation and inferior force (r = .51). No significant association was found between posterolateral translation and posterolateral force. Significant differences were found between dominant and non-dominant shoulders for posterolateral translation, posterolateral force to produce translation, and inferior translation values

  11. FIESTA: an MR arthrography celebration of shoulder joint anatomy, variants, and their mimics.

    PubMed

    Yu, D; Turmezei, T D; Kerslake, R W

    2013-03-01

    Magnetic resonance (MR) arthrography is currently the gold standard radiological investigation for shoulder joint instability. Not only does this investigation allow for identification of important disease processes, but the reduced slice thickness and increased in-plane resolution allowed by the latest imaging sequences also gives excellent demonstration of shoulder joint internal anatomy. This article describes the technique of MR arthrography of the shoulder practiced at our institution, briefly outlining features of the FIESTA (fast imaging employing steady state acquisition) MR sequence employed, including its advantages and limitations. A pictorial review of shoulder MR arthrography performed with this technique is presented, concentrating on normal shoulder joint internal anatomy and anatomical variants that may mimic pathology.

  12. Prevalence of shoulder pain in Swedish flatwater kayakers and its relation to range of motion and scapula stability of the shoulder joint.

    PubMed

    Johansson, Anette; Svantesson, Ulla; Tannerstedt, Jörgen; Alricsson, Marie

    2016-01-01

    Few studies have investigated the incidence of injuries in kayakers. The aim was to study the prevalence of shoulder pain in competitive flatwater kayakers and to evaluate any differences in range of motion or scapula stability of the shoulder joint among kayakers with or without the history of shoulder pain. Thirty-one kayakers were participated in the study, and a questionnaire including background data was used. Shoulder range of motion was measured with a goniometer, and the participants were observed for scapula dyskinesis in flexion and abduction. Of the participating kayakers, 54.8% (n = 17) had experienced shoulder pain. Kayakers who had experienced shoulder pain showed a significantly lower degree of internal rotational range of motion versus kayakers with no reported shoulder pain, with a mean degree of internal rotation in the right shoulder 49.3 vs. 60.0 (P = 0.017) and the left shoulder 51.9 vs. 66.0 (P = 0.000). Kayakers who had experienced shoulder pain were also observed with a scapular dyskinesis (n = 15 of 17 kayakers) to a significantly higher degree (P = 0.001) than kayakers with no reported shoulder pain. Findings suggest that screening for scapular dyskinesis and testing for rotational range of motion in the shoulder joint is essential in order to treat and maybe prevent shoulder pain in kayakers.

  13. Comparison of an EMG-based and a stress-based method to predict shoulder muscle forces.

    PubMed

    Engelhardt, Christoph; Malfroy Camine, Valérie; Ingram, David; Müllhaupt, Philippe; Farron, Alain; Pioletti, Dominique; Terrier, Alexandre

    2015-01-01

    The estimation of muscle forces in musculoskeletal shoulder models is still controversial. Two different methods are widely used to solve the indeterminacy of the system: electromyography (EMG)-based methods and stress-based methods. The goal of this work was to evaluate the influence of these two methods on the prediction of muscle forces, glenohumeral load and joint stability after total shoulder arthroplasty. An EMG-based and a stress-based method were implemented into the same musculoskeletal shoulder model. The model replicated the glenohumeral joint after total shoulder arthroplasty. It contained the scapula, the humerus, the joint prosthesis, the rotator cuff muscles supraspinatus, subscapularis and infraspinatus and the middle, anterior and posterior deltoid muscles. A movement of abduction was simulated in the plane of the scapula. The EMG-based method replicated muscular activity of experimentally measured EMG. The stress-based method minimised a cost function based on muscle stresses. We compared muscle forces, joint reaction force, articular contact pressure and translation of the humeral head. The stress-based method predicted a lower force of the rotator cuff muscles. This was partly counter-balanced by a higher force of the middle part of the deltoid muscle. As a consequence, the stress-based method predicted a lower joint load (16% reduced) and a higher superior-inferior translation of the humeral head (increased by 1.2 mm). The EMG-based method has the advantage of replicating the observed cocontraction of stabilising muscles of the rotator cuff. This method is, however, limited to available EMG measurements. The stress-based method has thus an advantage of flexibility, but may overestimate glenohumeral subluxation.

  14. Infected shoulder joint with loose Suture Anchor in the joint after Bankart’s Repair- A Case Report

    PubMed Central

    Kumar, Mukesh; Thilak, Jai

    2016-01-01

    Introduction: The glenoid labrum is frequently torn in traumatic glenohumeral dislocation; arthroscopic repair is the standard method of treatment. The complications associated with this repair are pulling out of metal suture anchors, chondrolysis and joint infection. The infection of joint after arthroscopy is less than 1%. Staphylococcus is most common organism and rarely followed by Pseudomonas aeruginosa. We report a case of infected shoulder with chondrolysis of the joint and pulled out metal suture anchor lying inside the joint after Bankart’s repair. Case Report: A 22-year-old gentleman came to us with complaints of shoulder joint pain & gross restriction of movements for one year, with history of intermittent fever and treatment in nearby hospital. He also gives past history of recurrent dislocation of shoulder with last episode 18 months back, which was diagnosed as Bankart’s lesion and arthroscopic Bankart’s repair was done 15 months back. He was evaluated at our institute and suspected to have infection of shoulder joint with pulled out metal suture anchor inside the joint. Arthroscopic removal of suture anchor and debridement of shoulder joint was done, Culture was obtained and culture specific antibiotics were given for six weeks, and significant improvement was observed with this line of treatment. At lyear follow up, the patient was able to perform his daily activities with terminal restriction of range of motion. Conclusions: Shoulder joint infection is rare after Bankart’s repair and required a high degree of suspicion. Any foreign materials inside the joint should be taken out & followed with aggressive treatment by debridement, irrigation and culture specific antibiotics. Suppression of joint infection with antibiotics should be avoided specially when there is foreign body inside the joint. PMID:27703928

  15. Effect of joint conformity on glenoid component fixation in total shoulder arthroplasty.

    PubMed

    Oosterom, R; Rozing, P M; Verdonschot, N; Bersee, H E N

    2004-01-01

    Results of shoulder replacements are inferior and must be improved. Two of the major problems of total shoulder replacements are loosening of cemented glenoid components and wear of polyethylene inlays of uncemented, metal-backed glenoid components. The aim of this study is to investigate the influence of joint conformity on glenoid-component fixation. Keeled glenoid components, with radii of curvature of 24, 25, or 29 mm, were cemented in bone substitutes, placed in a force-controlled test set-up, articulating against a 24 mm humeral head. They were loaded by a constant joint compression force (725 +/- 10 N) and a superior subluxation force (shear force), cyclically varying between 0 and 350 +/- 1 N. After 200,000 load cycles, the upper and lower glenoid component rim-displacements were measured by custom-made displacement sensors. Additionally, the shear-out strength has been measured to investigate the residual strength. The glenoid component structures with radii of curvature of 24, 25, and 29 mm showed maximum superior rim-displacements of 0.163 (SD = 0.01), 0.299 (SD = 0.0306), and 0.350 (SD = 0.0197) mm respectively, which is a significant difference (p < 0.05). The maximum shear-out strength of glenoid components with radii of curvature of 24, 25, and 29 mm was 2707 (SD = 452), 2648 (SD = 299), and 2631 (SD = 312) N respectively, which is not a significant difference (p < 0.05). However, the results indicate that a conform articulation shows smaller glenoid rim-displacements, which might be beneficial for long-term component fixation.

  16. Patients' experiences of telerehabilitation at home after shoulder joint replacement.

    PubMed

    Eriksson, Lisbeth; Lindström, Britta; Ekenberg, Lilly

    2011-01-01

    We investigated the experience of ten patients who received video-based physiotherapy at home for two months after a shoulder joint replacement. Videoconferencing took place via the patient's home broadband connection at a bandwidth of 256-768 kbit/s. Qualitative interviews were carried out, transcribed and analysed. Through qualitative content analysis six categories were identified: (1) a different reinforced communication; (2) pain-free exercising as an effective routine; (3) from a dependent patient to a strengthened person at home; (4) closeness at a distance; (5) facilitated daily living; and (6) continuous physiotherapy chain. The access to bodily knowledge, continuity, collaboration and being at home were all aspects that contributed to the patients' recovery. The patients described experiences of safety, and strengthening during their daily exercise routine at home. The frequent interplay with the patient during telerehabilitation made it possible for the physiotherapist to make an individual judgement about each patient; this could be one reason for the positive findings. Home video-based physiotherapy may be useful in other kinds of physiotherapy.

  17. VARIABILITY OF PEAK SHOULDER FORCE DURING WHEELCHAIR PROPULSION IN MANUAL WHEELCHAIR USERS WITH AND WITHOUT SHOULDER PAIN

    PubMed Central

    Moon, Y.; Chandrasekaran, J.; Hsu, I.M.K.; Rice, I.M.; Hsiao-Wecksler, E.T.; Sosnoff, J.J.

    2013-01-01

    Background Manual wheelchair users report a high prevalence of shoulder pain. Growing evidence shows that variability in forces applied to biological tissue is related to musculoskeletal pain. The purpose of this study was to examine the variability of forces acting on the shoulder during wheelchair propulsion as a function of shoulder pain. Methods Twenty-four manual wheelchair users (13 with pain, 11 without pain) participated in the investigation. Kinetic and kinematic data of wheelchair propulsion were recorded for three minutes maintaining a constant speed at three distinct propulsion speeds (fast speed of 1.1 m/s, a self-selected speed, and a slow speed of 0.7 m/s). Peak resultant shoulder forces in the push phase were calculated using inverse dynamics. Within individual variability was quantified as the coefficient of variation of cycle to cycle peak resultant forces. Findings There was no difference in mean peak shoulder resultant force between groups. The pain group had significantly smaller variability of peak resultant force than the no pain group (p < 0.01, η2 = 0.18). Interpretation The observations raise the possibility that propulsion variability could be a novel marker of upper limb pain in manual wheelchair users. PMID:24210512

  18. Friction stir spot welded joints of 409L stainless steels fabricated by a convex shoulder tool

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Abu Mowazzem; Hasan, Md. Tariqul; Hong, Sung-Tae; Miles, Michael; Cho, Hoon-Hwe; Han, Heung Nam

    2013-11-01

    Spot joints of ferritic 409L stainless steel are successfully fabricated by friction stir spot welding (FSSW) using a convex shoulder tool. The welding process, microstructure and failure of the FSSW joint are investigated experimentally. During the FSSW process, the Z-force history shows significant variations depending on the contact phenomena between the tool and the joined sheets, while the Z-torque history shows a rather steady increase without pronounced changes in the trend until the initiation of dwelling. Electron back-scatter diffraction suggests that both continuous dynamic recrystallization and recovery occurred in the stir zone during the FSSW process. Observation of the FSSW joint that failed under the given lap shear load shows that the cracks, which are the result of the interfaces between the upper and lower sheets, propagated into the weld along the interfacial surfaces, after which a necking/shear failure occurred. Finally, the rupture of the joint, which was initiated by the necking/shear failure, propagated along the circumference of the weld.

  19. Maximum force levels in different positions of shoulder and elbow.

    PubMed

    Castro, C; De la Vega, E; Báez, G; Carrasco, F

    2012-01-01

    The number of occupational diseases in Mexico is alarming and clearly it is important to do studies with the purpose of improving the design of workstations. The objective of this research is to determine the maximum force levels in different positions of shoulder and elbow. An experiment was conducted with 16 subjects between 18 and 28 years old: 8 male and 8 female. We considered 16 different positions, working with the right and left arm to perform the tasks of pull and push. The tasks consisted of pushing or pulling a dynamometer for a period of 3 seconds as hard as possible. The results were presented in tables. The tables show the mean, standard deviation and range of force levels in different positions.

  20. Arm and shoulder conditions, active component, U.S. Armed Forces, 2003-2012.

    PubMed

    2013-06-01

    This analysis estimated the incidence and health care burden of acute and chronic conditions of the arm and shoulder among active component service members of the Armed Forces from 1 January 2003 through 31 December 2012. There were 196,789 diagnosed incident cases of acute arm and shoulder conditions for a rate of 13.7 cases per 1,000 person-years. The annual incidence rates of sprains, the most common acute condition, nearly doubled during the period. Diagnoses of chronic conditions (overall rate of 28.8 per 1,000 person-years) increased 25 percent during the period, mainly associated with a doubling of the incidence of diagnoses of joint pain. Incidence rates of chronic disorders were progressively higher among successively older age groups of service members. The health care burden of all arm and shoulder conditions together steadily increased during the period, as indicated by numbers of health care encounters, individuals affected, and lost work time. The most commonly documented causes associated with acute and chronic conditions are described.

  1. Similarities in the neural control of the shoulder and elbow joints belie their structural differences.

    PubMed

    Karduna, Andrew R; Sainburg, Robert L

    2012-01-01

    Movement of the hand in three dimensional space is primarily controlled by the orientation of the shoulder and elbow complexes. Due to discrepancies in proprioceptive acuity, overlap in motor cortex representation and grossly different anatomies between these joints, we hypothesized that there would be differences in the accuracy of aimed movements between the two joints. Fifteen healthy young adults were tested under four conditions - shoulder motion with the elbow constrained and unconstrained, and elbow motion with the shoulder constrained and unconstrained. End point target locations for each joint were set to coincide with joint excursions of 10, 20 or 30 degrees of either the shoulder or elbow joint. Targets were presented in a virtual reality environment. For the constrained condition, there were no significant differences in angular errors between the two joints, suggesting that the central nervous system represents linked segment models of the limb in planning and controlling movements. For the unconstrained condition, although angle errors were higher, hand position errors remained the same as those of the constrained trials. These results support the idea that the CNS utilizes abundant degrees of freedom to compensate for the potentially different contributions to end-point errors introduced by each joint.

  2. Influence of Combinations of Shoulder, Elbow and Trunk Orientation on Elbow Joint Loads in Youth Baseball Pitchers

    PubMed Central

    Tanaka, Hiroshi; Hayashi, Toyohiko; Inui, Hiroaki; Ninomiya, Hiroki; Muto, Tomoyuki; Nobuhara, Katsuya

    2016-01-01

    Objectives: Shoulder and elbow pain in youth baseball pitchers is a well-recognized phenomenon. Common problems in pitching mechanics that can lead to injury begin with stride foot contact. The purpose of this study was to address the relationships between the combinations of shoulder, elbow and trunk orientation at the instant of stride foot contact and elbow joint loads in youth baseball pitchers. Methods: A total of 143 Japanese male youth baseball pitchers participated in this study after providing written informed consents approved by the hospital’s institutional review board. The procedures to be performed were also explained to their parent(s) or legal guardian(s). Each participant was not currently injured or recovering from an injury at time of testing. For data collection of baseball pitching, a set of 14-mm spherical reflective markers was placed on the skin overlying 34 anatomical landmarks determined. Subsequently, a motion capture three-dimensional automatic digitizing system was used to collect 500-Hz from 7 charge-coupled-device synchronized cameras was set up around the regulation pitching mound in an indoor laboratory. After performing a preparation routine of stretching and warm-up pitching, each player pitch to 5 fastball pitches off the pitching mound to a catcher at the regulation distance of 16 m for youth pitchers. The best pitch thrown for a strike was chosen for kinematic and kinetic analysis. The local coordinate systems were used to calculate 3-dimesional rotation at the trunk, shoulder and elbow using the typical Eulerian sequence. Afterward, the standard inverse dynamic equation was used to estimate resultant joint forces and torques at throwing shoulder and elbow. In order to normalize data between subjects, forces and torques were expressed as percent using body weight and height. A multiple regression analysis was carried out to assess the combined effects of shoulder (external rotation, abduction and horizontal adduction), elbow

  3. Joint Kinetics to Assess the Influence of the Racket on a Tennis Player’s Shoulder

    PubMed Central

    Creveaux, Thomas; Dumas, Raphaël; Hautier, Christophe; Macé, Pierre; Chèze, Laurence; Rogowski, Isabelle

    2013-01-01

    This study aimed at investigating the influence of three rackets on shoulder net joint moments, power and muscle activity during the flat tennis serve under field- conditions. A 6-camera Eagle® motion analysis system, operating at 256 Hz, captured racket and dominant upper limb kinematics of the serve in five tennis players under three racket conditions (A: low mass, high balance and polar moment, B: low three moments of inertia, and C: high mass, swingweight and twistweight). The electromyographic activity of six trunk and arm muscles was simultaneously recorded. Shoulder net joint moments and power were computed by 3D inverse dynamics. The results showed that greater shoulder joint power and internal/external rotation peak moments were found to accelerate and decelerate racket A in comparison with the racket C. Moreover, serving with the racket A resulted in less activity in latissimus dorsi muscle during the acceleration phase, and biceps brachii muscle during the follow-through phase when compared with racket C. These initial findings encourage studying the biomechanical measurements to quantify the loads on the body during play in order to reduce them, and then prevent shoulder injuries. Racket specifications may be a critical point for coaches who train players suffering from shoulder pain and chronic upper limb injuries should be considered in relation to the racket specifications of the players. Key Points Light racket required more joint power than heavy one to achieve similar post impact ball velocity. Serving with a light racket resulted in higher shoulder internal and external rotation moments than using a heavy one for similar performance. Chronic shoulder pain should encourage coaches to check for potentially inappropriate racket specifications of their players. PMID:24149804

  4. [Value of magnetic resonance imaging in the diagnosis of sequels of shoulder joint injuries].

    PubMed

    Murashina, I V; Egorova, E A

    2011-01-01

    The paper presents the results of examining 45 persons with sequels of shoulder joint injuries, by applying magnetic resonance imaging (MRI) (100%) and arthroscopy (95.6%). The data of arthroscopy were compared with those of MRI; thereafter the sensitivity, specificity, and accuracy of MRI were calculated. The findings suggested that there was no statistically significant difference in the capacities of the two comparable techniques MRI and arthroscopy to diagnose labral tears with degenerative changes, synovitis, bursitis and tendinitis (McNemar's test; p > 0.05). The capacities of MRI are greater than those of arthroscopy only to detect the structural disintegrity of the joint shoulder.

  5. Evaluation and management of adult shoulder pain: a focus on rotator cuff disorders, acromioclavicular joint arthritis, and glenohumeral arthritis.

    PubMed

    Armstrong, April

    2014-07-01

    Shoulder pain is a common reason for a patient to see their primary care physician. This article focuses on the evaluation and management of 3 common shoulder disorders; rotator cuff disorders, acromioclavicular joint arthritis, and glenohumeral joint arthritis. The typical history and physical examination findings for each of these entities are highlighted, in addition to treatment options.

  6. Development of an Arthroscopic Joint Capsule Injury Model in the Canine Shoulder

    PubMed Central

    Kovacevic, David; Baker, Andrew R.; Staugaitis, Susan M.; Kim, Myung-Sun; Ricchetti, Eric T.; Derwin, Kathleen A.

    2016-01-01

    Background The natural history of rotator cuff tears can be unfavorable as patients develop fatty infiltration and muscle atrophy that is often associated with a loss of muscle strength and shoulder function. To facilitate study of possible biologic mechanisms involved in early degenerative changes to rotator cuff muscle and tendon tissues, the objective of this study was to develop a joint capsule injury model in the canine shoulder using arthroscopy. Methods Arthroscopic surgical methods for performing a posterior joint capsulectomy in the canine shoulder were first defined in cadavers. Subsequently, one canine subject underwent bilateral shoulder joint capsulectomy using arthroscopy, arthroscopic surveillance at 2, 4 and 8 weeks, and gross and histologic examination of the joint at 10 weeks. Results The canine subject was weight-bearing within eight hours after index and follow-up surgeries and had no significant soft tissue swelling of the shoulder girdle or gross lameness. Chronic synovitis and macroscopic and microscopic evidence of pathologic changes to the rotator cuff bony insertions, tendons, myotendinous junctions and muscles were observed. Conclusions This study demonstrates feasibility and proof-of-concept for a joint capsule injury model in the canine shoulder. Future work is needed to define the observed pathologic changes and their role in the progression of rotator cuff disease. Ultimately, better understanding of the biologic mechanisms of early progression of rotator cuff disease may lead to clinical interventions to halt or slow this process and avoid the more advanced and often irreversible conditions of large tendon tears with muscle fatty atrophy. PMID:26808837

  7. New concepts in restoring shoulder elevation in a stiff and painful shoulder patient.

    PubMed

    Donatelli, Robert; Ruivo, R M; Thurner, Michael; Ibrahim, Mahmoud Ibrahim

    2014-02-01

    The treatment and evaluation of a stiff and painful shoulder, characteristic of adhesive capsulitis and "frozen" shoulders, is a dilemma for orthopedic rehabilitation specialists. A stiff and painful shoulder is all-inclusive of Adhesive capsulitis and Frozen Shoulder diagnoses. Adhesive capsulitis and frozen shoulder will be referred to as a stiff and painful shoulder, throughout this paper. Shoulder motion occurs in multiple planes of movement. Loss of shoulder mobility can result in significant functional impairment. The traditional treatment approach to restore shoulder mobility emphasizes mobilization of the shoulder overhead. Forced elevation in a stiff and painful shoulder can be painful and potentially destructive to the glenohumeral joint. This manuscript will introduce a new biomechanical approach to evaluate and treat patients with stiff and painful shoulders.

  8. Assessment of Correlation Between MRI and Arthroscopic Pathologic Findings in the Shoulder Joint

    PubMed Central

    Momenzadeh, Omid R; Gerami, Mohamad H; Sefidbakht, Sepideh; Dehghani, Sakineh

    2015-01-01

    Background: The objective of this study was to determine the diagnostic value of magnetic resonance imaging for shoulder joint pathologies and then compare the results with arthroscopy, the standard for joint diagnosis. Methods: In this cross-sectional study, 80 patients with shoulder joint disorders, who underwent final arthroscopy, were studied. Based on patients’ medical history and physical examinations, shoulder MRI was requested if paraclinical investigations were. If non-surgical therapies failed, arthroscopy of the affected shoulder was done and the same structures were inspected. Subsequently, sensitivity, specificity, and positive and negative predictive values (PPV) and (NPV) of MRI were determined by arthroscopy comparisons. Results: The highest sensitivity, specificity, PPV and NPV were found in MRI pathology reports that included: Hill-Sach lesion (0.910), infraspinatus tendon (0.985), supraspinatus tendon (0.930), and biceps tendon (0.954), respectively. Rotator interval (0.250), biceps labrum complex (0.805), subscapularis tendon (0.538) and anterior labrum lesions (0.604) had the lowest sensitivity, specificity, PPV and NPV, respectively. Conclusion: The results showed that MRI can be a useful tool in ruling out possible abnormalities in the shoulder and to give clues to the most probable diagnosis. Although knowing some practical skills in order to successfully perform the procedure and experience of the radiologist with suitable feedback by surgeon is necessary. PMID:26550595

  9. Effect of different hand positions on trunk and shoulder kinematics and reaction forces in sitting pivot transfer.

    PubMed

    Kim, Sung Shin; Her, Jin Gan; Ko, Tae Sung

    2015-07-01

    [Purpose] The purpose of this study was to compare the changes in trunk and shoulder angles, and reaction forces under the two hands elicited by different hand base of support positions during sitting pivot transfer. [Subjects and Methods] Eighteen unimpaired subjects performed independent sitting pivot transfer. Subjects performed sitting pivot transfer between an initial seat to a target seat by only using their hands positioned at the same height as and lower than the seat position. Trunk and shoulder kinematics, and reaction forces on the trailing and leading hands were calculated. Mean peak joint angles and forces were compared between the hand positions using the pared t-test for the lift phase of the transfer. [Results] There were significant increases in the trunk angles of forward and lateral flexion, even though rotation decreased while transferring in the lower hand position. Increased shoulder flexion, anterior/posterior forces and reduced lateral forces were also shown. [Conclusion] Placing the hands of the supporting arms lower than the seat position during sitting pivot transfer was identified as having biomechanical advantages. Therefore, the lower hand position can be recommended as an effective and safe method for sitting pivot transfer by patients with spinal cord injury and can be utilized as a reference data for considering the appropriate height of aids for a wheelchair.

  10. Effect of different hand positions on trunk and shoulder kinematics and reaction forces in sitting pivot transfer

    PubMed Central

    Kim, Sung Shin; Her, Jin Gan; Ko, Tae Sung

    2015-01-01

    [Purpose] The purpose of this study was to compare the changes in trunk and shoulder angles, and reaction forces under the two hands elicited by different hand base of support positions during sitting pivot transfer. [Subjects and Methods] Eighteen unimpaired subjects performed independent sitting pivot transfer. Subjects performed sitting pivot transfer between an initial seat to a target seat by only using their hands positioned at the same height as and lower than the seat position. Trunk and shoulder kinematics, and reaction forces on the trailing and leading hands were calculated. Mean peak joint angles and forces were compared between the hand positions using the pared t-test for the lift phase of the transfer. [Results] There were significant increases in the trunk angles of forward and lateral flexion, even though rotation decreased while transferring in the lower hand position. Increased shoulder flexion, anterior/posterior forces and reduced lateral forces were also shown. [Conclusion] Placing the hands of the supporting arms lower than the seat position during sitting pivot transfer was identified as having biomechanical advantages. Therefore, the lower hand position can be recommended as an effective and safe method for sitting pivot transfer by patients with spinal cord injury and can be utilized as a reference data for considering the appropriate height of aids for a wheelchair. PMID:26310994

  11. Objective evaluation of the shoulder dystocia phenomenon: effect of maternal pelvic orientation on force reduction.

    PubMed

    Gonik, B; Allen, R; Sorab, J

    1989-07-01

    This report describes the use of maternal pelvic and fetal models, a tactile sensing glove, and a microcomputer data acquisition system to measure fetal shoulder extraction forces. Sixty-nine experiments were carried out in the laboratory setting to simulate vaginal delivery of the aftercoming fetal shoulders. The tests were conducted using a variety of fetal biclavicular diameters (10-13 cm) and maternal pelvic angle positions (McRoberts, 10 degrees; lithotomy, 25 degrees). When comparing lithotomy versus McRoberts positioning, there was a consistent reduction in force needed to extract the fetal shoulders with the latter maneuver. No simulated clavicles were fractured during shoulder delivery until a biclavicular diameter of 12.0 cm was reached. At this point, five of eight clavicles (63%) were fractured at 25 degrees and zero of seven (0%) were fractured at 10 degrees (P less than .025). For all 69 experiments, fetal neck extension readings were consistently lower than the total traction forces recorded by the tactile sensing glove. This suggests that, in addition to the axially oriented fetal neck forces, a component of flexion (lateral force) was also present. As the difficulty of shoulder delivery increased, the impact of these inadvertent flexion forces became most pronounced at the level of the brachial plexus. This is the first study to measure shoulder extraction forces reproducibly using a laboratory model for shoulder dystocia and to describe the pathophysiology of specific neonatal injuries from a force perspective. The results document objectively that McRoberts positioning reduces shoulder extraction forces, brachial plexus stretching, and the incidence of clavicular fracture.

  12. Functional Anatomy of the Shoulder

    PubMed Central

    Terry, Glenn C.; Chopp, Thomas M.

    2000-01-01

    Objective: Movements of the human shoulder represent the result of a complex dynamic interplay of structural bony anatomy and biomechanics, static ligamentous and tendinous restraints, and dynamic muscle forces. Injury to 1 or more of these components through overuse or acute trauma disrupts this complex interrelationship and places the shoulder at increased risk. A thorough understanding of the functional anatomy of the shoulder provides the clinician with a foundation for caring for athletes with shoulder injuries. Data Sources: We searched MEDLINE for the years 1980 to 1999, using the key words “shoulder,” “anatomy,” “glenohumeral joint,” “acromioclavicular joint,” “sternoclavicular joint,” “scapulothoracic joint,” and “rotator cuff.” Data Synthesis: We examine human shoulder movement by breaking it down into its structural static and dynamic components. Bony anatomy, including the humerus, scapula, and clavicle, is described, along with the associated articulations, providing the clinician with the structural foundation for understanding how the static ligamentous and dynamic muscle forces exert their effects. Commonly encountered athletic injuries are discussed from an anatomical standpoint. Conclusions/Recommendations: Shoulder injuries represent a significant proportion of athletic injuries seen by the medical provider. A functional understanding of the dynamic interplay of biomechanical forces around the shoulder girdle is necessary and allows for a more structured approach to the treatment of an athlete with a shoulder injury. PMID:16558636

  13. Shoulder tendinitis and osteoarthrosis of the acromioclavicular joint and their relation to sports.

    PubMed Central

    Stenlund, B

    1993-01-01

    A sample of 207 men from the construction industry was studied using an epidemiological technique of cross-sectional design to investigate if sport activities involving the arms increase the risk of developing shoulder tendinitis or osteoarthrosis of the acromioclavicular joint. The relative risk for shoulder tendinitis was estimated to be 9.5 on the right side, and 4.9 on the left side for a lifetime of sport activity exceeding 8399 h. Subjects who reported both extremely high physical load from work and from sports had an estimated relative risk for signs of shoulder tendinitis of 5.9 on the right side and 10.4 on the left side. High sport activity yielded relative risks of 4.6 on the right side and 2.8 on the left side for osteoarthrosis of the acromioclavicular joint. The combination of high activity in sports and high exposure to load lifted during work yielded relative risks for osteoarthrosis of the acromioclavicular joint of 12.5 on the right side and 6.7 on the left side. There seems to be an increased risk for shoulder tendinitis and acromioclavicular osteoarthrosis for subjects who have been extremely active in sports, and an even higher risk for those who have been extremely active in sports and also report a high exposure to load lifted during work. PMID:8358584

  14. Dislocated Shoulder

    MedlinePlus

    ... gradual rehabilitation program designed to restore range of motion, strength and stability to your shoulder joint. If ... when the pain improves. Maintain the range of motion of your shoulder. After one or two days, ...

  15. Shoulder replacement

    MedlinePlus

    ... the opening at the end of the shoulder blade, called the socket. This type of joint allows ... head. The socket part (glenoid) of your shoulder blade will be replaced with a smooth plastic shell ( ...

  16. Scapular Dyskinesis is Detrimental to Shoulder Tendon Properties and Joint Mechanics in a Rat Model

    PubMed Central

    Reuther, Katherine E.; Thomas, Stephen J.; Tucker, Jennica J.; Yannascoli, Sarah M.; Caro, Adam C.; Vafa, Rameen P.; Liu, Stephen S.; Gordon, Joshua A.; Bhatt, Pankti R.; Kuntz, Andrew F.; Soslowsky, Louis J.

    2015-01-01

    Shoulder tendon injuries are frequently seen in the presence of abnormal scapular motion, termed scapular dyskinesis. The cause and effect relationship between scapular dyskinesis and shoulder injury has not been directly defined. The objective of this study was to develop and use an animal model to examine the initiation and progression of pathological changes in the rotator cuff and biceps tendon. 60 male Sprague-Dawley rats were randomized into two groups: nerve transection (to induce scapular dyskinesis, SD) or sham nerve transection (control). The animals were sacrificed 4 and 8 weeks after surgery. Shoulder function and passive joint mechanics were evaluated over time. Tendon mechanical, histological, organizational, and compositional properties were evaluated at 4 and 8 weeks. Gross observation demonstrated alterations in scapular motion, consistent with scapular “winging”. Shoulder function, passive internal range of motion, and tendon mechanical properties were significantly altered. Histology results, consistent with tendon pathology (rounded cell shape and increased cell density), were observed and protein expression of collagen III and decorin was altered. This study presents a new model of scapular dyskinesis that can rigorously evaluate cause and effect relationships in a controlled manner. These results identify scapular dyskinesis as a causative mechanical mechanism for shoulder tendon pathology. PMID:25070580

  17. A Biomechanical Model of the Scapulothoracic Joint to Accurately Capture Scapular Kinematics during Shoulder Movements

    PubMed Central

    Seth, Ajay; Matias, Ricardo; Veloso, António P.; Delp, Scott L.

    2016-01-01

    The complexity of shoulder mechanics combined with the movement of skin relative to the scapula makes it difficult to measure shoulder kinematics with sufficient accuracy to distinguish between symptomatic and asymptomatic individuals. Multibody skeletal models can improve motion capture accuracy by reducing the space of possible joint movements, and models are used widely to improve measurement of lower limb kinematics. In this study, we developed a rigid-body model of a scapulothoracic joint to describe the kinematics of the scapula relative to the thorax. This model describes scapular kinematics with four degrees of freedom: 1) elevation and 2) abduction of the scapula on an ellipsoidal thoracic surface, 3) upward rotation of the scapula normal to the thoracic surface, and 4) internal rotation of the scapula to lift the medial border of the scapula off the surface of the thorax. The surface dimensions and joint axes can be customized to match an individual’s anthropometry. We compared the model to “gold standard” bone-pin kinematics collected during three shoulder tasks and found modeled scapular kinematics to be accurate to within 2mm root-mean-squared error for individual bone-pin markers across all markers and movement tasks. As an additional test, we added random and systematic noise to the bone-pin marker data and found that the model reduced kinematic variability due to noise by 65% compared to Euler angles computed without the model. Our scapulothoracic joint model can be used for inverse and forward dynamics analyses and to compute joint reaction loads. The computational performance of the scapulothoracic joint model is well suited for real-time applications; it is freely available for use with OpenSim 3.2, and is customizable and usable with other OpenSim models. PMID:26734761

  18. Effects of a shoulder injury prevention strength training program on eccentric external rotator muscle strength and glenohumeral joint imbalance in female overhead activity athletes.

    PubMed

    Niederbracht, Yvonne; Shim, Andrew L; Sloniger, Mark A; Paternostro-Bayles, Madeline; Short, Thomas H

    2008-01-01

    Imbalance of the eccentrically-activated external rotator cuff muscles versus the concentrically-activated internal rotator cuff muscles is a primary risk factor for glenohumeral joint injuries in overhead activity athletes. Nonisokinetic dynamometer based strength training studies, however, have focused exclusively on resulting concentric instead of applicable eccentric strength gains of the external rotator cuff muscles. Furthermore, previous strength training studies did not result in a reduction in glenoumeral joint muscle imbalance, thereby suggesting that currently used shoulder strength training programs do not effectively reduce the risk of shoulder injury to the overhead activity athlete. Two collegiate women tennis teams, consisting of 12 women, participated in this study throughout their preseason training. One team (n = 6) participated in a 5-week, 4 times a week, external shoulder rotator muscle strength training program next to their preseason tennis training. The other team (n = 6) participated in a comparable preseason tennis training program, but did not conduct any upper body strength training. Effects of this strength training program were evaluated by comparing pre- and posttraining data of 5 maximal eccentric external immediately followed by concentric internal contractions on a Kin-Com isokinetic dynamometer (Chattecx Corp., Hixson, Tennessee). Overall, the shoulder strength training program significantly increased eccentric external total work without significant effects on concentric internal total work, concentric internal mean peak force, or eccentric external mean peak force. In conclusion, by increasing the eccentric external total exercise capacity without a subsequent increase in the concentric internal total exercise capacity, this strength training program potentially decreases shoulder rotator muscle imbalances and the risk for shoulder injuries to overhead activity athletes.

  19. A 200-m All-out Front-crawl Swim Modifies Competitive Swimmers' Shoulder Joint Position Sense.

    PubMed

    Uematsu, A; Kurita, Y; Inoue, K; Okuno, K; Hortobágyi, T; Suzuki, S

    2015-11-01

    We tested the hypothesis that an all-out-effort 200-m front-crawl swim trial affects competitive swimmers' shoulder joint position sense. On Day 1, we measured shoulder joint position sense before and after the swim trial, and on Day 2 before and after 2 min of seated rest. On both days, shoulder joint position sense was measured in the seated position using electromagnetic movement sensors in a position-matching paradigm. An investigator abducted participants' left (reference) shoulder joint in the frontal plane to test angles of 90°, 135°, and 180°. Participants then actively abducted the right (indicator) shoulder joint to match the position of the left, reference arm. After the 200-m all-out front-crawl swim trial, the indicator relative to the reference angle differed by 4.4° toward adduction at the 180° (vertical) testing position (P<0.05). Variation in absolute matching error was 3.2° or 2.2 times greater after swim compared with the no-swim control trial. An all-out 200-m front-crawl swim trial can selectively increase competitive swimmers' shoulder joint position sense error and increase variation in matching error in horizontal arm position.

  20. Shoulder joint movement of the non-throwing arm during baseball pitch--comparison between skilled and unskilled pitchers.

    PubMed

    Murata, A

    2001-12-01

    The shoulder of a non-throwing arm during a baseball pitch must be in a constant position while the shoulder of the throwing arm moves in a nearly circular path around it. However, it has not been investigated whether a skilled pitch requires less shoulder-joint movement. It was hypothesized that pitchers with less shoulder movement of the non-throwing arm can be considered to have higher skill and to attain higher initial ball velocity. Nine baseball pitchers were used as subjects. The coach classified them into a skilled and an unskilled group. The pitching motions were recorded using two high-speed cameras. The time series of three-dimensional landmark coordinates of the shoulder joint of the non-throwing arm during the baseball pitch were calculated using the direct linear transformation method. The shoulder-joint movement (SJM) index, which expresses the movement (displacement) of the shoulder joint of the non-throwing arm quantitatively, was proposed to compare the SJM at different skill levels and investigate the relationship between SJM and initial ball velocity. The SJM of the skilled pitchers was smaller than that of the unskilled pitchers, and the smaller value of the SJM led to faster initial ball velocity. The data suggest that the less SJM of the non-throwing arm is required to attain a skilled pitch and higher initial ball velocity.

  1. Program Calculates Forces in Bolted Structural Joints

    NASA Technical Reports Server (NTRS)

    Buder, Daniel A.

    2005-01-01

    FORTRAN 77 computer program calculates forces in bolts in the joints of structures. This program is used in conjunction with the NASTRAN finite-element structural-analysis program. A mathematical model of a structure is first created by approximating its load-bearing members with representative finite elements, then NASTRAN calculates the forces and moments that each finite element contributes to grid points located throughout the structure. The user selects the finite elements that correspond to structural members that contribute loads to the joints of interest, and identifies the grid point nearest to each such joint. This program reads the pertinent NASTRAN output, combines the forces and moments from the contributing elements to determine the resultant force and moment acting at each proximate grid point, then transforms the forces and moments from these grid points to the centroids of the affected joints. Then the program uses these joint loads to obtain the axial and shear forces in the individual bolts. The program identifies which bolts bear the greatest axial and/or shear loads. The program also performs a fail-safe analysis in which the foregoing calculations are repeated for a sequence of cases in which each fastener, in turn, is assumed not to transmit an axial force.

  2. Shoulder joint and muscle characteristics in the recreational weight training population.

    PubMed

    Kolber, Morey J; Beekhuizen, Kristina S; Cheng, Ming-Shun S; Hellman, Madeleine A

    2009-01-01

    Shoulder disorders attributed to weight training are well documented in the literature; however, a paucity of evidence-based research exists to describe risk factors inherent to participation. Shoulder joint and muscle characteristics in the recreational weight training (RWT) population were investigated to determine specific risk-related adaptations that may occur from participation. Ninety participants, men between the ages of 19 and 47 (mean age 28.9), including 60 individuals who participated in upper-extremity RWT and 30 controls with no record of RWT participation, were recruited. Active range of motion (AROM), posterior shoulder tightness (PST), body weight-adjusted strength values, and agonist/antagonist strength ratios were compared between the RWT participants and the control group. Statistical analysis identified significant differences (p < 0.001) between the groups when analyzing shoulder mobility. The RWT participants had decreased mobility when compared with the control group for all AROM measurements except external rotation, which was greater. Strength ratios were significantly greater in the RWT group when compared with the control group (p shoulder disorders in the general and athletic population; thus, these imbalances may place RWT participants at risk for injury. Common training patterns are biased toward large muscle groups such as the pectorals and deltoids but neglect muscles responsible for stabilization such as the external rotators and lower trapezius. Exercise selection that mitigates strength and mobility imbalances may serve to prevent injury in this population. Clinicians and strength and conditioning professionals should consider the biomechanical stresses and adaptations associated

  3. Joint Force Quarterly. Issue 35

    DTIC Science & Technology

    2004-10-01

    necessary to know your friends. Making ene- mies is easy, but it is harder to make friends. The wrong approach to allied or occupied countries can...members of the Armed Forces will be familiar with cultural traditions of the countries in which they operate. Yet violation of local norms and...tive lessons from Afghanistan or Iraq, it is clear that the Armed Forces lack sophisticated knowl- edge of foreign countries . That does not dishonor

  4. Joint Force Quarterly. Issue 37

    DTIC Science & Technology

    2005-04-01

    Cooperation: The First Step by Matthew F. Bogdanos 19 U.S. European Command and Transformation by Charles F. Wald 27 Transformation and the...JFCOM) found that “JIACG has gained universal acceptance.”1 Deputy Secretary of Defense Paul Wolfowitz then notified Deputy National Secu- rity... Wolfowitz , “Joint Interagency Coordination Groups (JIACG) Assessment,” memoran- dum for the Assistant to the President and Deputy National Security

  5. Segmentation and measurement of collagen fibers for shoulder and joint therapy studies

    SciTech Connect

    Mascio, L.

    1994-11-15

    Various shoulder instabilities are debilitating, especially in individuals who perform overhead activities. Thermal modification of soft tissues in joints may allow precise alteration of these tissues` mechanical and/or structural properties to enhance joint function without inducing cell death or an inflammatory response. Several studies have evaluated laser energy for tissue welding. The collective findings are promising, and the next step is to identify the mechanisms responsible for laser-induced capsular tissue alternation, and the short- and long-term effects of non-ablative laser energy on joint capsular tissue. One step toward this goal is to compare the effect of three laser energy densities on the histologic properties of the tissue evaluating the architecture of the collagen (including density, fibril diameter distribution, and interfibrillar space) in sheep at various time intervals after surgery. The specific computer algorithms that are being used to make these measurements will be described.

  6. SOF: A Joint Force Integrator

    DTIC Science & Technology

    2007-04-05

    abilities to communicate, enhance efficiencies, and empower midlevel managers with strategic decisions within their domain. Take for example how pop...typically gains the upper hand, leaving the slower competitor on their heels, attempting to conduct damage control . Often in recent times , the United...the need for the use of force during the appropriate times , but also takes consideration for 29

  7. Shoulder separation - aftercare

    MedlinePlus

    Separated shoulder - aftercare; Acromioclavicular joint separation - aftercare; A/C separation - aftercare ... Most shoulder separation injuries are caused by falling onto the shoulder. This causes a tear in the tissue that connects the ...

  8. Physiotherapy at a distance: a controlled study of rehabilitation at home after a shoulder joint operation.

    PubMed

    Eriksson, Lisbeth; Lindström, Britta; Gard, Gunvor; Lysholm, Jack

    2009-01-01

    We explored the benefit of video communication in home rehabilitation after shoulder joint replacement and compared it to referral for physiotherapy in the conventional way. A total of 22 patients were included in the study. The intervention group (n = 10) had training at home under the supervision of a physiotherapist at the hospital using videoconferencing. The control group (n = 12) had physiotherapy training in a conventional way in their home town. All patients had the same postoperative, three-phase-programme for two months. The outcome measures were a Visual Analogue Scale (VAS) for pain, range of motion (ROM), shoulder function ability (Constant score and SRQ-S) and health-related quality of life (SF-36). Questions about areas of priority for improvement and general satisfaction with the shoulder were also included. The telemedicine group received a greater number of treatments compared to the control group. After the intervention, there were significant improvements in VAS-pain, Constant score and SRQ-S for both groups. The telemedicine group improved significantly more in all three measurements than the control group (P < 0.001 for all). When changes from baseline to follow-up were compared, the telemedicine group improved significantly more in terms of decrease in pain (P = 0.004) and vitality (P = 0.001) than the control group. Despite some limitations, there seem to be clear benefits from physiotherapy at a distance with a telemedicine technique that allows patients to obtain access to physiotherapy at home.

  9. Effect of brief daily resistance training on rapid force development in painful neck and shoulder muscles: randomized controlled trial

    PubMed Central

    Jay, Kenneth; schraefel, mc; Andersen, Christoffer H; Ebbesen, Frederik S; Christiansen, David H; Skotte, Jørgen; Zebis, Mette K; Andersen, Lars L

    2013-01-01

    Objective: To determine the effect of small daily amounts of progressive resistance training on rapid force development of painful neck/shoulder muscles. Methods: 198 generally healthy adults with frequent neck/shoulder muscle pain (mean: age 43·1 years, computer use 93% of work time, 88% women, duration of pain 186 day during the previous year) were randomly allocated to 2- or 12 min of daily progressive resistance training with elastic tubing or to a control group receiving weekly information on general health. A blinded assessor took measures at baseline and at 10-week follow-up; participants performed maximal voluntary contractions at a static 90-degree shoulder joint angle. Rapid force development was determined as the rate of torque development and maximal muscle strength was determined as the peak torque. Results: Compared with the control group, rate of torque development increased 31·0 Nm s−1 [95% confidence interval: (1·33–11·80)] in the 2-min group and 33·2 Nm s−1 (1·66–12·33) in the 12-min group from baseline to 10-week follow-up, corresponding to an increase of 16·0% and 18·2% for the two groups, respectively. The increase was significantly different compared to controls (P<0·05) for both training groups. Maximal muscle strength increased only ∼5–6% [mean and 95% confidence interval for 2- and 12-min groups to control, respectively: 2·5 Nm (0·05–0·73) and 2·2 Nm (0·01–0·70)]. No significant differences between the 2- and 12-min groups were evident. A weak but significant relationship existed between changes in rapid force development and pain (r = 0·27, P<0·01), but not between changes in maximal muscle strength and pain. Conclusion: Small daily amounts of progressive resistance training in adults with frequent neck/shoulder pain increases rapid force development and, to a less extent, maximal force capacity. PMID:23758661

  10. Knee joint forces: prediction, measurement, and significance

    PubMed Central

    D’Lima, Darryl D.; Fregly, Benjamin J.; Patil, Shantanu; Steklov, Nikolai; Colwell, Clifford W.

    2011-01-01

    Knee forces are highly significant in osteoarthritis and in the survival and function of knee arthroplasty. A large number of studies have attempted to estimate forces around the knee during various activities. Several approaches have been used to relate knee kinematics and external forces to internal joint contact forces, the most popular being inverse dynamics, forward dynamics, and static body analyses. Knee forces have also been measured in vivo after knee arthroplasty, which serves as valuable validation of computational predictions. This review summarizes the results of published studies that measured knee forces for various activities. The efficacy of various methods to alter knee force distribution, such as gait modification, orthotics, walking aids, and custom treadmills are analyzed. Current gaps in our knowledge are identified and directions for future research in this area are outlined. PMID:22468461

  11. Using your shoulder after replacement surgery

    MedlinePlus

    Joint replacement surgery - using your shoulder; Shoulder replacement surgery - after ... You have had shoulder replacement surgery to replace the bones of your shoulder joint with artificial parts. The parts include a stem made of metal and a ...

  12. Joint Force Quarterly. Number 15, Spring 1997

    DTIC Science & Technology

    1997-06-01

    the number of tasks or steps necessary to defeat an enemy grew dramati- cally. There is evidence of this in the rapid in- crease in the size of...have found it much more difficult to execute Desert Storm. Until alternatively powered vehicles and weapons are de- veloped, logistics will remain...over military operations. More - over, as General Joulwan notes in his ar- ticle, a new array of concepts such as the combined joint task force, Partner

  13. Joint Force Quarterly. Number 22, Summer 1999

    DTIC Science & Technology

    1999-08-01

    promote understanding of the integrated employment of land, sea, air, space, and special operations forces. The journal focuses on joint doctrine, coalition...other agency of the Federal Government. Copyrighted portions of this journal may not be reproduced or extracted without permission of copyright...Army Command and General Staff College LtCol James I. Van Zummeren, USMC ■ Marine Corps War College A PROFESSIONAL MILITARY JOURNAL (continued from page

  14. Joint Force Quarterly. Number 19, Summer 1998

    DTIC Science & Technology

    1998-08-01

    Airborne outside Tuzla Air Base (U.S. Army/Larry Lane), issue 13 (Autumn 96). The front inside cover shows flight deck crew rigging barricade (U.S. Navy...From the Sea.” If tested synergism is the most compelling view since it draws on common ground which the services have developed through joint...prepare for the ar- rival of ground and ground - based air power. Once accomplished, according to this argu- ment, naval forces fight alongside the other

  15. Joint Task Force on Undergraduate Physics Programs

    NASA Astrophysics Data System (ADS)

    This session will focus on the guidelines and recommendations being developed by the APS/AAPT Joint Task Force on Undergraduate Physics Programs. J-TUPP is studying how undergraduate physics programs might better prepare physics majors for diverse careers. The guidelines and recommendations will focus on curricular content, flexible tracks, pedagogical methods, research experiences and internships, the development of professional skills, and enhanced advising and mentoring for all physics majors.

  16. Joint Force Quarterly. Number 1, Summer 1993

    DTIC Science & Technology

    1993-01-01

    conduct joint operations to only “higher” levels is a recipe for missed opportunities, longer and more difficult operations, riskier outcomes, greater...changed the face of Europe, Asia, and Africa. The passing of the Cold War now has map-makers scrambling for pens and fresh ink, while territorial squabbles...America’s future is best served by a force mix that does not place too many eggs in any one basket, but which in- stead draws on the synergy of

  17. Shoulder biomechanics.

    PubMed

    Lugo, Roberto; Kung, Peter; Ma, C Benjamin

    2008-10-01

    The biomechanics of the glenohumeral joint depend on the interaction of both static and dynamic-stabilizing structures. Static stabilizers include the bony anatomy, negative intra-articular pressure, the glenoid labrum, and the glenohumeral ligaments along with the joint capsule. The dynamic-stabilizing structures include the rotator cuff muscles and the other muscular structures surrounding the shoulder joint. The combined effect of these stabilizers is to support the multiple degrees of motion within the glenohumeral joint. The goal of this article is to review how these structures interact to provide optimal stability and how failure of some of these mechanisms can lead to shoulder joint pathology.

  18. "Floating shoulder" injuries.

    PubMed

    Heng, Kenneth

    2016-12-01

    "Floating shoulder" is a rare injury complex resulting from high-energy blunt force trauma to the shoulder, resulting in scapulothoracic dissociation. It is commonly associated with catastrophic neurovascular injury. Two cases of motorcyclists with floating shoulder injuries are described.

  19. Virtual power based algorithm for decoupling large motions from infinitesimal strains: application to shoulder joint biomechanics.

    PubMed

    Büchler, P; Rakotomanana, L; Farron, A

    2002-12-01

    New trends of numerical models of human joints require more and more computation of both large amplitude joint motions and fine bone stress distribution. Together, these problems are difficult to solve and very CPU time consuming. The goal of this study is to develop a new method to diminish the calculation time for this kind of problems which include calculation of large amplitude motions and infinitesimal strains. Based on the Principle of Virtual Power, the present method decouples the problem into two parts. First, rigid body motion is calculated. The bone micro-deformations are then calculated in a second part by using the results of rigid body motions as boundary conditions. A finite element model of the shoulder was used to test this decoupling technique. The model was designed to determine the influence of humeral head shape on stress distribution in the scapula for different physiological motions of the joint. Two versions of the model were developed: a first version completely deformable and a second version based on the developed decoupling method. It was shown that biomechanical variables, as mean pressure and von Mises stress, calculated with the two versions were sensibly the same. On the other hand, CPU time needed for calculating with the new decoupled technique was more than 6 times less than with the completely deformable model.

  20. Shoulder and hip joints for hard space suits and the like

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C.

    1986-01-01

    For use in hard space suits and the like, a joint between the torso covering and the upper arm covering (i.e., shoulder) or between the torso covering and upper leg covering (i.e., hip) is disclosed. Each joint has an outer covering and a inner covering. The outer covering has plural perferably truncated toroidal sections decreasing in size proceeding outwardly. In one embodiment at each joint there are two bearings, the first larger than the second. The outer race of the larger bearing is attached to the outer edge of the smaller end of each section and the inner race of the larger bearing is attached to the end wall. The inner race of the smaller bearing is attached to the end wall. The outer race of the smaller bearing is attached to the larger end of the next section. Each bearing hask appropriate seals. Between each section is a rubber ring for the comfort of the wearer. Such rubber rings have radial flanges attached to the inner races of two adjacent bearings. Matching semicircular grooves are formed in the abutting overlapping surfaces. Bellows-like inner walls are also provided for each section fixed at one end to an inner cylindrical flange and, at the opposite end, to an end wall. Each outer section may rotate 360 deg relative to the next outer section, whereas the bellows sections do not rotate, but rather expand or contract locally as the rigid sections rotate relative to each other.

  1. Effect of Welding Speed on Joint Features and Lap Shear Properties of Stationary Shoulder FSLWed Alclad 2024 Al Alloy

    NASA Astrophysics Data System (ADS)

    Xu, Zhiwu; Li, Zhengwei; Lv, Zan; Zhang, Liguo

    2017-02-01

    Using alclad 2024-T4 aluminum alloy as the research object, stationary shoulder technology was used in friction stir lap welding process to investigate its performance in this study. Joint features and mechanical properties of the lap joints were mainly investigated. Results show that lap joint with smooth surface, without shoulder marks and inner defects can be obtained using the stationary shoulder technology. With increasing the welding speed from 40 to 130 mm/min, effective sheet thickness (EST) at the advancing side (AS) shows rather stable values (from 1.17 to 1.31 mm), EST at the retreating side (RS) increases from 0.57 to 1.13 mm, and stir zone width decreases from 4.95 to 4.44 mm. Lap shear failure load of the SSFSLW joints firstly increases and then decreases with increasing the welding speed. Using 100 mm/min, the maximum failure loads of 15.85 and 9.01 kN were obtained when the RS and AS of the joint bear the main load during the lap shear test. Shear fracture mode and tensile fracture mode can be obtained during the lap shear test. All joints present ductile fracture mode.

  2. Effect of Welding Speed on Joint Features and Lap Shear Properties of Stationary Shoulder FSLWed Alclad 2024 Al Alloy

    NASA Astrophysics Data System (ADS)

    Xu, Zhiwu; Li, Zhengwei; Lv, Zan; Zhang, Liguo

    2017-03-01

    Using alclad 2024-T4 aluminum alloy as the research object, stationary shoulder technology was used in friction stir lap welding process to investigate its performance in this study. Joint features and mechanical properties of the lap joints were mainly investigated. Results show that lap joint with smooth surface, without shoulder marks and inner defects can be obtained using the stationary shoulder technology. With increasing the welding speed from 40 to 130 mm/min, effective sheet thickness (EST) at the advancing side (AS) shows rather stable values (from 1.17 to 1.31 mm), EST at the retreating side (RS) increases from 0.57 to 1.13 mm, and stir zone width decreases from 4.95 to 4.44 mm. Lap shear failure load of the SSFSLW joints firstly increases and then decreases with increasing the welding speed. Using 100 mm/min, the maximum failure loads of 15.85 and 9.01 kN were obtained when the RS and AS of the joint bear the main load during the lap shear test. Shear fracture mode and tensile fracture mode can be obtained during the lap shear test. All joints present ductile fracture mode.

  3. The friction coefficient of shoulder joints remains remarkably low over 24 h of loading.

    PubMed

    Jones, Brian K; Durney, Krista M; Hung, Clark T; Ateshian, Gerard A

    2015-11-05

    The frictional response of whole human joints over durations spanning activities of daily living has not been reported previously. This study measured the friction of human glenohumeral joints during 24 h of reciprocal loading in a pendulum testing device, at moderate (0.2 mm/s, 4320 cycles) and low (0.02 mm/s, 432 cycles) sliding speeds, under a 200 N load. The effect of joint congruence was also investigated by testing human humeral heads against significantly larger mature bovine glenoids. Eight human joints and six bovine joints were tested in four combinations: human joints tested at moderate (hHCMS, n=6) and low speed (hHCLS, n=3), human humeral heads tested against bovine glenoids at moderate speed (LCMS, n=3), and bovine joints tested at moderate speed (bHCMS, n=3). In the first half hour the mean±standard deviation of the friction coefficient was hHCMS: 0.0016±0.0011, hHCLS: 0.0012±0.0002, LCMS: 0.0008±0.0002 and bHCMS: 0.0024±0.0008; in the last four hours it was hHCMS: 0.0057±0.0025, hHCLS: 0.0047±0.0017, LCMS: 0.0012±0.0003 and bHCMS: 0.0056±0.0016. The initial value was lower than the final value (p<0.0001). The value in LCMS was significantly lower than in hHCMS and bHCMS (p<0.01). No visual damage was observed in any of the specimens. These are the first results to demonstrate that the friction coefficient of natural human shoulders remains remarkably low (averaging as little as 0.0015 and no greater than 0.006) for up to 24 h of continuous loading. The sustained low friction coefficients observed in incongruent joints (~0.001) likely represent rolling rather than sliding friction.

  4. The Standing Joint Force Headquarters: A Planning Multiplier?

    DTIC Science & Technology

    2006-05-25

    a Standing Joint Task Force Headquarters through its’ European Plans and Operations Center ( EPOC ). The European Plans and Operations Center was...elements of the Joint Forces Command Standing Joint Force Headquarters with minor modifications to meet EUCOM’s unique requirements.120 The EPOC contains...about half of the EPOC are assigned to the Joint Operations Center and the remainder were added as critical personnel as exercise planners, 36 121 Ibid

  5. Effect of extracorporeal shock wave therapy on the shoulder joint functional status of patients with calcific tendinitis

    PubMed Central

    Kim, Eun-Kyung; Kwak, Kwang-Il

    2016-01-01

    [Purpose] This study aimed to analyze the effect of extracorporeal shock wave therapy on the shoulder function of patients with calcific tendinitis through a 12-week follow-up. [Subjects and Methods] A total of 34 patients with calcific tendinitis participated in this study. In the extracorporeal shock wave therapy group, 18 patients received 6-week extracorporeal shock wave therapy and 12-week follow-up. The Constant-Murley scale was used to evaluate shoulder joint function. [Results] Analysis of variance showed a significant difference between the measurement periods. The independent t-test showed significant differences between the groups at 2, 6, and 12 weeks. [Conclusion] Extracorporeal shock wave therapy can be an effective treatment method for calcific tendinitis that affects patients’ shoulder function. PMID:27799684

  6. 76 FR 1975 - Disestablishment of United States Joint Forces Command

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-11

    ... Memorandum of January 6, 2011--Disestablishment of United States Joint Forces Command #0; #0; #0... of United States Joint Forces Command Memorandum for the Secretary of Defense Pursuant to my... Secretary of Defense and Chairman of the Joint Chiefs of Staff and approve the disestablishment of...

  7. Absolute reliability of shoulder joint horizontal adductor muscle strength measurements using a handheld dynamometer.

    PubMed

    Hirano, Masahiro; Katoh, Munenori

    2015-07-01

    [Purpose] The aim of this study was to verify the absolute reliability of shoulder joint horizontal adductor muscle strength measurements using a handheld dynamometer (HHD). [Subjects and Methods] The subjects were 33 healthy college students. The measurements were made three times with the HHD fixed using a belt (BFHHD) or with the examiner's hand (conventional method; HFHHD). The absolute reliability of measurements was verified using Bland-Altman analysis, both in the all subjects group and a group of subjects showing measurements less than a fixed limit of 30 kgf. [Results] In the <30 kgf group, a systematic bias was not observed, and BFHHD values were greater than HFHHD values. BFHHD values in the all subjects group showed a systematic bias; the 3rd measurement value was less than the maximum value obtained during the 1st and 2nd measurements. [Conclusion] For obtaining an acceptable value during clinical measurements of horizontal adductor muscle strength, single measurements obtained using an HFHHD in the case of a <30 kgf group and the maximum value of two measurements obtained using a BFHHD are reliable.

  8. Joint Space Forces in Theater: Coordination is No Longer Sufficient

    DTIC Science & Technology

    2007-04-01

    any other service or joint body, the Air Force has pushed the development of space systems, doctrine, procedures, and education . As the Department...operations and staff assignments. His assignments include Chief of Standardization and Evaluation for the 6th Space Operations Squadron, Offutt AFB...Force, Vandenberg AFB; and Chief of Joint Exercise Development , Headquarters Air Force Space Command, Peterson AFB. He has served in Combined/Joint

  9. The Impact of Nationalism on Joint Force Planning

    DTIC Science & Technology

    1996-01-01

    Understanding the dynamics of nationalism will remain critical to re- gional security affairs and joint force planning . Planning Implications Tension results...assigned to the Office of National Security Issues at the Defense Intelligence Agency. The Impact of NATIONALISM ON JOINT FORCE PLANNING By G E O R G E...COVERED 00-00-1995 to 00-00-1996 4. TITLE AND SUBTITLE The Impact of Nationalism on Joint Force Planning 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

  10. Shoulder Impingement Treatment

    MedlinePlus

    ... imbalance in the rotator cuff or scapular muscles, postural abnormalities, shoulder joint instability, or improper training or ... with elastic tubing. Figure 2. Shoulder protraction exercise (balance with one arm on wobble board or deflated ...

  11. Muscle force and excursion requirements and moment arm analysis of a posterior-superior offset reverse total shoulder prosthesis.

    PubMed

    Onstot, Brian R; Jacofsky, Marc C; Hansen, Matthew L

    2013-01-01

    Current reverse total shoulder arthroplasty prosthesis designs do not permit offset of the humerus in the sagittal plane. Posteriorly shifting the humerus has the theoretical benefit of lengthening the infraspinatus and teres minor muscles and their external rotation moment arms, thereby improving the tension and efficiency of each external rotator and subsequently requiring each muscle to produce less force to rotate the arm. A cadaveric shoulder controller was used to quantify the impact of a novel posterior-superior offset reverse shoulder prosthesis on muscle length, moment arms, and muscle forces relative to a non-offset reverse shoulder design during two different motions: scapular plane abduction and internal/external rotation. The results of this study demonstrate that both the non-offset and offset reverse shoulder designs had similar force and excursion demands of the infraspinatus and teres minor muscles during both scapular abduction and internal and external rotation. Additionally, the offset reverse shoulder design was associated with significantly less over-tensioning of the middle and posterior deltoid and significantly more anatomic tensioning of the teres minor than the non-offset design. However, the offset reverse shoulder was observed to have more impingement than the non-offset design. These findings support the feasibility of this design: by restoring a more anatomic resting length to the deltoid and teres minor, the posterior-superior offset rTSA design may provide better teres minor function and rotational strength and may decrease the incidence of acromial stress fractures relative to the non-offset design. Clinical follow-up is required to confirm these findings.

  12. The validation of a human force model to predict dynamic forces resulting from multi-joint motions

    NASA Technical Reports Server (NTRS)

    Pandya, Abhilash K.; Maida, James C.; Aldridge, Ann M.; Hasson, Scott M.; Woolford, Barbara J.

    1992-01-01

    The development and validation is examined of a dynamic strength model for humans. This model is based on empirical data. The shoulder, elbow, and wrist joints were characterized in terms of maximum isolated torque, or position and velocity, in all rotational planes. This data was reduced by a least squares regression technique into a table of single variable second degree polynomial equations determining torque as a function of position and velocity. The isolated joint torque equations were then used to compute forces resulting from a composite motion, in this case, a ratchet wrench push and pull operation. A comparison of the predicted results of the model with the actual measured values for the composite motion indicates that forces derived from a composite motion of joints (ratcheting) can be predicted from isolated joint measures. Calculated T values comparing model versus measured values for 14 subjects were well within the statistically acceptable limits and regression analysis revealed coefficient of variation between actual and measured to be within 0.72 and 0.80.

  13. Limits of the manipulative-fixed method for measurement of shoulder joint horizontal adduction muscle strength using a handheld dynamometer.

    PubMed

    Hirano, Masahiro; Katoh, Munenori

    2015-01-01

    [Purpose] The aim of this study was to verify the limit of isometric muscle strength of shoulder joint horizontal adduction using handheld dynamometer (HHD) manipulated by hand (referred to as the manipulative-fixed method). [Subjects and Methods] The subjects were 33 healthy college students. The examiner was a healthy college student. Shoulder joint horizontal adductor muscle strength was measured using HHD with the subject in the supine position. The belt-fixed and manipulative-fixed methods were used to secure the HHD sensor unit. The limitations of the manipulative-fixed method were assessed by simple regression analysis, in which the participants were divided into 2 groups according to a branch point. The slope of the straight line of the graph was visualized. [Results] Single regression analysis of the <30 kgf group revealed significant results. The results of single regression of the >30 kgf group were not significant. [Conclusion] The manipulative-fixed method is simple to perform. However, there exists the possibility that the actual muscle strength is not measurable by this method. The measurement limit of the shoulder horizontal adduction strength with the manipulative-fixed method was 30 kgf in the case of the examiner in the present study. The fixed limit was also found to influence in the muscle strength of the upper limbs.

  14. Effects of Gait Speed of Femoroacetabular Joint Forces

    PubMed Central

    Irmischer, Bobbie S.; Sievert, Zachary A.

    2017-01-01

    Alterations in hip joint loading have been associated with diseases such as arthritis and osteoporosis. Understanding the relationship between gait speed and hip joint loading in healthy hips may illuminate changes in gait mechanics as walking speed deviates from preferred. The purpose of this study was to quantify hip joint loading during the gait cycle and identify differences with varying speed using musculoskeletal modeling. Ten, healthy, physically active individuals performed walking trials at their preferred speed, 10% faster, and 10% slower. Kinematic, kinetic, and electromyographic data were collected and used to estimate hip joint force via a musculoskeletal model. Vertical ground reaction forces, hip joint force planar components, and the resultant hip joint force were compared between speeds. There were significant increases in vertical ground reaction forces and hip joint forces as walking speed increased. Furthermore, the musculoskeletal modeling approach employed yielded hip joint forces that were comparable to previous simulation studies and in vivo measurements and was able to detect changes in hip loading due to small deviations in gait speed. Applying this approach to pathological and aging populations could identify specific areas within the gait cycle where force discrepancies may occur which could help focus management of care. PMID:28260849

  15. Battlefield Renewable Energy: A Key Joint Force Enabler

    DTIC Science & Technology

    2010-06-01

    Environment, Energy Security & Sustainability Symposium Jun 2010 Battlefield Renewable Energy A Key Joint Force Enabler Roy H. Adams III, LTC, USA...COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Battlefield Renewable Energy : A Key Joint Force Enabler 5a. CONTRACT NUMBER 5b. GRANT

  16. Proprioception assessment in subjects with idiopathic loss of shoulder range of motion: joint position sense and a novel proprioceptive feedback index.

    PubMed

    Yang, Jing-Lan; Chen, Shiauyee; Jan, Mei-Hwa; Lin, Yeong-Fwu; Lin, Jiu-jenq

    2008-09-01

    We examined the effects of elevation range and plane on shoulder joint proprioception in subjects with idiopathic loss of shoulder range of motion (ROM). Joint position sense (JPS) and a novel proprioceptive feedback index (PFI), including difference magnitude and the similarity index, were used to assess proprioception. Twelve subjects (eight male, four female) with involved stiff shoulders and normal opposite shoulders were recruited from a university hospital. Subjects attempted to repeat six target positions. Target positions consisted of arm elevation in three planes (frontal, scapular, and sagittal planes) and two ranges (end/mid range). Six trials of each target position were used to determine acceptable trials for stabilization of the data, less than 5% of the cumulative mean values for at least three successive trials. The data stabilized at the sixth repetition. Compared to control shoulders, involved shoulders had enhanced proprioception during end range movements (p < 0.05). The magnitude of the repositioning error and difference magnitude decreased (1.6 degrees -3.5 degrees for repositioning error and 22.2 degrees -62.1 degrees for difference magnitude), whereas similarity index improved at end range movements compared to mid range movements (p < 0.05) in involved stiff shoulders. Results of JPS and PFI suggest that both capsuloligamentous and musculotendinous mechanoreceptors play an important role in proprioception feedback during active movements in subjects with idiopathic loss of shoulder ROM.

  17. Organizing for Effective Joint Warfare: A Deductive Analysis of U.S. Armed Forces Joint Doctrine

    DTIC Science & Technology

    1993-06-18

    AD-A266 735 (Unclassified Paper) NAVAL WAR COLLEGE Newport, R.I. ORGANIZING FOR EFFECTIVE JOINT WARFARE: A DEDUCTIVE ANALYSIS OF U.S. ARMED FORCES...8217biGJ-Tji--𔃼T JOINT WARFLRE: A DEDUCTIVE ANALYSIS OF U.S. ARMED FORGES JOINT DOCTRINE (j 12. PERSONAL AUTHOR(S) JESSE J. KELSO, GOMI-ANDER. U. S... ANALYSIS OF U.S. ARMED FORCES JOINT DOCTRINE Using organizational concepts embodied in existing joint doctrine, this paper deduces rational criteria for

  18. Automatic bone segmentation and bone-cartilage interface extraction for the shoulder joint from magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Yang, Zhengyi; Fripp, Jurgen; Chandra, Shekhar S.; Neubert, Aleš; Xia, Ying; Strudwick, Mark; Paproki, Anthony; Engstrom, Craig; Crozier, Stuart

    2015-02-01

    We present a statistical shape model approach for automated segmentation of the proximal humerus and scapula with subsequent bone-cartilage interface (BCI) extraction from 3D magnetic resonance (MR) images of the shoulder region. Manual and automated bone segmentations from shoulder MR examinations from 25 healthy subjects acquired using steady-state free precession sequences were compared with the Dice similarity coefficient (DSC). The mean DSC scores between the manual and automated segmentations of the humerus and scapula bone volumes surrounding the BCI region were 0.926  ±  0.050 and 0.837  ±  0.059, respectively. The mean DSC values obtained for BCI extraction were 0.806  ±  0.133 for the humerus and 0.795  ±  0.117 for the scapula. The current model-based approach successfully provided automated bone segmentation and BCI extraction from MR images of the shoulder. In future work, this framework appears to provide a promising avenue for automated segmentation and quantitative analysis of cartilage in the glenohumeral joint.

  19. Redefining Joint Fires Service Functions to Better Support Joint Force Operations

    DTIC Science & Technology

    2012-06-01

    of tasks and systems that provide the collective and coordinated use of Army indirect fires, air and missile defense (AMD), and joint fires...effort. Operational fires can occur anywhere within the Joint Operating Area (JOA) and may be delivered via a variety of platforms, weapon systems ...freedom of maneuver for the joint force. They require defensive fires to protect the force. The JFC, using systems that allow rapid response to changes

  20. Elastic Tape Improved Shoulder Joint Position Sense in Chronic Hemiparetic Subjects: A Randomized Sham-Controlled Crossover Study

    PubMed Central

    Souza, Matheus Bragança; Desloovere, Kaat; Russo, Thiago Luiz

    2017-01-01

    Background Elastic tape has been widely used in clinical practice in order to improve upper limb (UL) sensibility. However, there is little evidence that supports this type of intervention in stroke patients. Objective To verify the effect of elastic tape, applied to the paretic shoulder, on joint position sense (JPS) during abduction and flexion in subjects with chronic hemiparesis compared to sham tape (non-elastic tape). Furthermore, to verify if this potential effect is correlated to shoulder subluxation measurements and sensorimotor impairment. Methods A crossover and sham-controlled study was conducted with post-stroke patients who were randomly allocated into two groups: 1) those who received Sham Tape (ST) first and after one month they received Elastic Tape (ET); 2) those who received Elastic Tape (ET) first and after one month they received Sham Tape (ST). The JPS was evaluated using a dynamometer. The absolute error for shoulder abduction and flexion at 30° and 60° was calculated. Sensorimotor impairment was determined by Fugl-Meyer, and shoulder subluxation was measured using a caliper. Results Thirteen hemiparetic subjects (average time since stroke 75.23 months) participated in the study. At baseline (before interventions), the groups were not different for abduction at 30° (p = 0.805; p = 0.951), and 60° (p = 0.509; p = 0.799), or flexion at 30° (p = 0.872; p = 0.897) and 60° (p = 0.853; p = 0.970). For the ET group, differences between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° p<0.010) and 60° (p<0.010) were observed. For the ST group, differences were also observed between pre and post-elastic tape for abduction at 30° (p<0.010) and 60° (p<0.010), and flexion at 30° (p<0.010,) and 60° (p<0.010). Potential effects were only correlated with shoulder subluxation during abduction at 30° (p = 0.001, r = -0.92) and 60° (p = 0.020, r = -0.75). Conclusion Elastic tape improved shoulder

  1. Implementing Joint Operational Access: From Concept to Joint Force Development

    DTIC Science & Technology

    2014-01-01

    multiple DOTMLPF-P gover - nance processes across the Department of Defense (DOD). Finally, pulling all of the various activities together related to JOA...eral Martin E . Dempsey signed the Joint Concept for Entry Operations (JCEO) on April 7, 2014. 5 Sustaining U.S. Global Leadership, 5. 6 JOAC, 33–36

  2. In Vivo Evaluation of the Potential of High-Frequency Ultrasound for Arthroscopic Examination of the Shoulder Joint

    PubMed Central

    Puhakka, Jani; Afara, Isaac O.; Paatela, Teemu; Sormaala, Markus J.; Timonen, Matti A.; Virén, Tuomas; Jurvelin, Jukka S.; Töyräs, Juha; Kiviranta, Ilkka

    2015-01-01

    Objective Accurate arthroscopic evaluation of cartilage lesions could significantly improve the outcome of repair surgery. In this study, we investigated for the first time the potential of intra-articular ultrasound as an arthroscopic tool for grading cartilage defects in the human shoulder joint in vivo and compared the outcome to results from arthroscopic evaluation and magnetic resonance imaging findings. Design A total of 26 sites from 9 patients undergoing routine shoulder arthroscopy were quantitatively evaluated with a clinical intravascular (40MHz) ultrasound imaging system, using the regular arthroscopy portals. Reflection coefficient (R), integrated reflection coefficient (IRC), apparent integrated backscattering (AIB), and ultrasound roughness index (URI) were calculated, and high-resolution ultrasound images were obtained per site. Each site was visually graded according to the International Cartilage Repair Society (ICRS) system. “Ultrasound scores” corresponding to the ICRS system were determined from the ultrasound images. Magnetic resonance imaging was conducted and cartilage integrity at each site was classified into 5 grades (0 = normal, 4 = severely abnormal) by a radiologist. Results R and IRC were lower at sites with damaged cartilage surface (P = 0.033 and P = 0.043, respectively) and correlated with arthroscopic ICRS grades (rs = −0.444, P = 0.023 and rs = −0.426, P = 0.03, respectively). Arthroscopic ICRS grades and ultrasound scores were significantly correlated (rs = 0.472, P = 0.015), but no significant correlation was found between magnetic resonance imaging data and other parameters. Conclusion The results suggest that ultrasound arthroscopy could facilitate quantitative clinical appraisal of articular cartilage integrity in the shoulder joint and provide information on cartilage lesion depth and severity for quantitative diagnostics in surgery. PMID:27375840

  3. Determinants and magnitudes of manual force strengths and joint moments during two-handed standing maximal horizontal pushing and pulling.

    PubMed

    Chow, Amy Y; Dickerson, Clark R

    2016-04-01

    Pushing and pulling are common occupational exertions that are increasingly associated with musculoskeletal complaints. This study focuses on the sensitivity of shoulder capacity to gender, handle height, exertion type (push or pull) and handle orientation for these tasks. All factors except for handle orientation influenced unilateral and total manual force strength (p < 0.01), with exertion type being the most influential. Interaction effects also existed between handle height and exertion type. Additionally, joint moments at the shoulders and low back were influenced by all factors studied (p < 0.01), with exertion type again being most influential. Knowledge of the relative influence of multiple factors on shoulder capacity can provide guidance regarding these factors when designing or evaluating occupational pushing and pulling tasks for a diverse population. Practitioner Summary: pushing and pulling comprise nearly half of all manual materials handling tasks. Practitioners often assess, design or modify these tasks while incorporating constraints, including manual force direction and handle interface. This study provides guidance to aid design of pushing and pulling tasks in the context of shoulder physical capacity.

  4. Joint Force Quarterly. Number 32, Autumn 2002

    DTIC Science & Technology

    2002-12-01

    nature of civil -military relations, and the relative development of state-of-the-art technology all shape wartime mobilization. By combining and...winning the global war on terrorism. Although the joint team has technologically superior weapons, command and control systems, and re- connaissance...Coordination by Charles N. Cardinal, Timber P. Pangonas, and Edward Marks 54 Civil -Military Operations: Joint Doctrine and the Malayan Emergency by

  5. Joint Force Transformation to Fight the Global War on Terrorism

    DTIC Science & Technology

    2004-03-08

    JOINT FORCE TRANSFORMATION TO FIGHT THE GLOBAL WAR ON TERRORISM Capt Stephen Guse LTC Paul Disney...for the collection of information is estimated to average 1 hour per response , including the time for reviewing instructions, searching existing data...AND SUBTITLE Joint Force Transformation to Fight the Global War on Terrorism 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  6. Does surgery for instability of the shoulder truly stabilize the glenohumeral joint?

    PubMed Central

    Lädermann, Alexandre; Denard, Patrick J.; Tirefort, Jérôme; Kolo, Frank C.; Chagué, Sylvain; Cunningham, Grégory; Charbonnier, Caecilia

    2016-01-01

    Abstract Despite the fact that surgery is commonly used to treat glenohumeral instability, there is no evidence that such treatment effectively corrects glenohumeral translation. The purpose of this prospective clinical study was to analyze the effect of surgical stabilization on glenohumeral translation. Glenohumeral translation was assessed in 11 patients preoperatively and 1 year postoperatively following surgical stabilization for anterior shoulder instability. Translation was measured using optical motion capture and computed tomography. Preoperatively, anterior translation of the affected shoulder was bigger in comparison to the normal contralateral side. Differences were significant for flexion and abduction movements (P < 0.001). Postoperatively, no patients demonstrated apprehension and all functional scores were improved. Despite absence of apprehension, postoperative anterior translation for the surgically stabilized shoulders was not significantly different from the preoperative values. While surgical treatment for anterior instability limits the chance of dislocation, it does not seem to restore glenohumeral translation during functional range of motion. Such persistent microinstability may explain residual pain, apprehension, inability to return to activity and even emergence of dislocation arthropathy that is seen in some patients. Further research is necessary to better understand the causes, effects, and treatment of residual microinstability following surgical stabilization of the shoulder. PMID:27495043

  7. Shoulder function, pain and health related quality of life in adults with joint hypermobility syndrome/Ehlers-Danlos syndrome-hypermobility type.

    PubMed

    Johannessen, Elise Christine; Reiten, Helle Sundnes; Løvaas, Helene; Maeland, Silje; Juul-Kristensen, Birgit

    2016-07-01

    Purpose To investigate shoulder function, pain and Health-Related Quality of life (HRQoL) among adults with joint hypermobility syndrome/Ehlers-Danlos syndrome-hypermobility type (JHS/EDS-HT), compared with the general population (controls). Method In a cross-sectional study using postal survey, 110 patients diagnosed with JHS/EDS-HT and 140 gender- and age-matched healthy controls from Statistics Norway participated. Shoulder function, pain and HRQol were registered by Western Ontario Shoulder Instability Index (WOSI), Numerical Rating Scale (NRS), pain drawings, 36-item Short Form (SF-36). Results Eighty-one individuals responded, with response rate 34% (JHS/EDS-HT: 53%, controls: 21%). JHS/EDS-HT had lower shoulder function (WOSI total: 49.9 versus 83.3; p < 0.001), lower HRQol on SF-36 Physical Component Scale (PCS: 28.1 versus 49.9; p < 0.001), and higher pain intensity (NRS: 6.4 versus 2.7; p < 0.001) than controls. Neck and shoulder joints were rated as primary painful areas in both groups, with significantly higher frequency in JHS/EDS-HT (neck: 90% versus 27%; shoulder: 80% versus 37%). Further, JHS/EDS-HT most often reported generalized pain (96%). Conclusions Adults with JHS/EDS-HT have impaired shoulder function, increased pain intensity, as well as reduced physical HRQoL compared with controls. Although neck and shoulder were most frequently rated as painful, significantly more JHS/EDS-HT also reported generalized pain compared to controls. Implications for Rehabilitation Adults with JHS/EDS-HT have impaired shoulder function, and most often painful areas in the neck and shoulder joints, which need to be targeted in the treatment strategy. Compared with the general population adults with JHS/EDS-HT have reduced physical HRQoL, supporting a physical approach for this group. Adults with JHS/EDS-HT may present with both specific painful joints and generalized pain.

  8. The effects of shoulder joint abduction angles on the muscle activity of the serratus anterior muscle and the upper trapezius muscle while vibrations are applied.

    PubMed

    Jung, Da-Eun; Moon, Dong-Chul

    2015-01-01

    [Purpose] The purpose of this study was to examine the ratio between the upper trapezius and the serratus anterior muscles during diverse shoulder abduction exercises applied with vibrations in order to determine the appropriate exercise methods for recovery of scapular muscle balance. [Subjects and Methods] Twenty-four subjects voluntarily participated in this study. The subjects performed shoulder abduction at various shoulder joint abduction angles (90°, 120°, 150°, 180°) with oscillation movements. [Results] At 120°, all the subjects showed significant increases in the muscle activity of the serratus anterior muscle in comparison with the upper trapezius muscle. However, no significant difference was found at angles other than 120°. [Conclusion] To selectively strengthen the serratus anterior, applying vibration stimuli at the 120° shoulder abduction position is considered to be appropriate.

  9. The National Guard: Recommendations to Develop the Joint Future Force

    DTIC Science & Technology

    2010-03-01

    author of this paper, is a requirement to educate the military personnel on total force and joint concepts from the earliest stages. Aristotle once...8 Phillip S. Meilinger, American Airpower Biography : A Survey of the Field Air and Space Power (Maxwell Air Force Base, AL: Air University Press

  10. Putting the shoulder to the wheel: a new biomechanical model for the shoulder girdle.

    PubMed

    Levin, S M

    1997-01-01

    The least successfully modeled joint complex has been the shoulder. In multi-segmented mathematical shoulder models rigid beams (the bones) act as a series of columns or levers to transmit forces or loads to the axial skeleton. Forces passing through the almost frictionless joints must, somehow, always be directed perfectly perpendicular to the joints as only loads directed at right angles to the surfaces could transfer across frictionless joints. Loads transmitted to the axial skeleton would have to pass through the moving ribs or the weak jointed clavicle and then through the ribs. A new model of the shoulder girdle, based on the tension icosahedron described by Buckminster Fuller, is proposed that permits the compression loads passing through the arm and shoulder to be transferred to the axial skeleton through its soft tissues. In this model the scapula 'floats' in the tension network of shoulder girdle muscles just as the hub of the wire wheel is suspended in its tension network of spokes. With this construct inefficient beams and levers are eliminated. A more energy efficient, load distributing, integrated, hierarchical system is created.

  11. Using the American alligator and a repeated-measures design to place constraints on in vivo shoulder joint range of motion in dinosaurs and other fossil archosaurs.

    PubMed

    Hutson, Joel D; Hutson, Kelda N

    2013-01-15

    Using the extant phylogenetic bracket of dinosaurs (crocodylians and birds), recent work has reported that elbow joint range of motion (ROM) studies of fossil dinosaur forearms may be providing conservative underestimates of fully fleshed in vivo ROM. As humeral ROM occupies a more central role in forelimb movements, the placement of quantitative constraints on shoulder joint ROM could improve fossil reconstructions. Here, we investigated whether soft tissues affect the more mobile shoulder joint in the same manner in which they affect elbow joint ROM in an extant archosaur. This test involved separately and repeatedly measuring humeral ROM in Alligator mississippiensis as soft tissues were dissected away in stages to bare bone. Our data show that the ROMs of humeral flexion and extension, as well as abduction and adduction, both show a statistically significant increase as flesh is removed, but then decrease when the bones must be physically articulated and moved until they separate from one another and/or visible joint surfaces. A similar ROM pattern is inferred for humeral pronation and supination. All final skeletonized ROMs were less than initial fully fleshed ROMs. These results are consistent with previously reported elbow joint ROM patterns from the extant phylogenetic bracket of dinosaurs. Thus, studies that avoid separation of complementary articular surfaces may be providing fossil shoulder joint ROMs that underestimate in vivo ROM in dinosaurs, as well as other fossil archosaurs.

  12. Cyber Situational Awareness for Joint Force Commanders

    DTIC Science & Technology

    2012-02-15

    Officer assigned to the Air War College, Air University, Maxwell AFB, AL. Lt Col Payne is a graduate of Ohio University with a Bachelor of Science...manner. The central thesis being addressed is that military commanders need a common framework for cyber situation awareness in order to aid the force...The central thesis being addressed is that military commanders need a common framework for cyber SA in order to aid the force with building a

  13. Joint Force Quarterly. Number 18, Spring 1998

    DTIC Science & Technology

    1998-06-01

    collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 1998 2. REPORT TYPE 3. DATES COVERED 00-00...We have implemented various initiatives to reduce risks and better manage readiness. They include better control of selected low density/high demand...training, tactics, and command and control . Exploiting the full potential of RMA requires linking emerging tech- nologies in a coherent framework of joint

  14. Shoulder electromyography in multidirectional instability.

    PubMed

    Morris, Alfred D; Kemp, Graham J; Frostick, Simon P

    2004-01-01

    We studied shoulder muscle activity in multidirectional instability (MDI) and multidirectional laxity (MDL) of the shoulder, our hypothesis being that altered muscle activity plays a role in their pathogenesis. Six muscles (supraspinatus, infraspinatus, subscapularis, anterior deltoid, middle deltoid, and posterior deltoid) were investigated by use of intramuscular dual fine-wire electrodes in 7 normal shoulders, 5 MDL shoulders, and 6 MDI shoulders. Each subject performed 5 types of exercise (rotation in neutral, 45 degrees of abduction, 90 degrees of abduction, flexion/extension, and abduction/adduction) on an isokinetic muscle dynamometer at two rates, 90 degrees /s and 180 degrees /s. After filtering, rectification, and smoothing, the electromyography signal was normalized by using the peak voltage of the movement cycle. In subjects with MDI, compared with normal subjects, activity patterns of the anterior deltoid were different during rotation in neutral and 90 degrees of abduction, whereas those of the middle and posterior deltoid were different during rotation in 90 degrees of abduction. In subjects with MDL, the posterior deltoid showed increased activity compared with normal subjects during adduction. Activity patterns of the supraspinatus, infraspinatus, and subscapularis appeared similar in both groups. Dual fine-wire electromyography offers insight into the complex role of shoulder girdle muscle function in normal movement and in instability. Altered patterns of shoulder girdle muscle activity and imbalances in muscle forces support the theory that impaired coordination of shoulder girdle muscle activity and inefficiency of the dynamic stabilizers of the glenohumeral joint are involved in the etiology of MDI. Interestingly, the abnormalities are in the deltoid rather than the muscles of the rotator cuff.

  15. Stress analysis of bolted joints under centrifugal force

    NASA Astrophysics Data System (ADS)

    Imura, Makoto; Iizuka, Motonobu; Nakae, Shigeki; Mori, Takeshi; Koyama, Takayuki

    2014-06-01

    Our objective is to develop a long-life rotary machine for synchronous generators and motors. To do this, it is necessary to design a high-strength bolted joint, which is responsible for fixing a salient pole on a rotor shaft. While the rotary machine is in operation, not only centrifugal force but also moment are loaded on a bolted joint, because a point of load is eccentric to a centre of a bolt. We tried to apply the theory proposed in VDI2230-Blatt1 to evaluate the bolted joint under eccentric force, estimate limited centrifugal force, which is the cause of partial separation between the pole and the rotor shaft, and then evaluate additional tension of a bolt after the partial separation has occurred. We analyzed the bolted joint by FEM, and defined load introduction factor in that case. Additionally, we investigated the effect of the variation of bolt preload on the partial separation. We did a full scale experiment with a prototype rotor to reveal the variation of bolt preload against tightening torque. After that, we verified limited centrifugal force and the strength of the bolted joint by the VDI2230-Blatt1 theory and FEM considering the variation of bolt preload. Finally, we could design a high-strength bolted joint verified by the theoretical study and FEM analysis.

  16. Frozen Shoulder

    MedlinePlus

    ... you are put to sleep. Your doctor will force your shoulder to move which causes the capsule and scar tissue to stretch or tear. This releases the tightening and increases range of motion. These photos taken through an arthroscope show a ...

  17. Intrarater reliabilities of shoulder joint horizontal adductor muscle strength measurements using a handheld dynamometer for geriatric and stroke patients.

    PubMed

    Hirano, Masahiro; Katoh, Munenori; Kawaguchi, Saori; Uemura, Tomomi

    2016-01-01

    [Purpose] This study aimed to verify the appropriate number of measurements and the intrarater reliabilities of shoulder joint horizontal adductor muscle strength measurements using a handheld dynamometer (HHD) for geriatric and stroke patients. [Subjects and Methods] The subjects were 40 inpatients, who were divided into two groups: 20 stroke patients in the stroke group (SG), and 20 geriatric patients in the no-stroke group (N-SG). Measurements were performed three times using an HHD with a belt. The reliability was verified using Bland-Altman analysis and the intraclass correlation coefficient (ICC). [Results] ICC (1, 1) was >0.9. A systematic bias was not observed between the first and second measurement values except for the right side in N-SG. A systematic bias between the maximum value obtained during the first and second measurements and third measurement value was observed on the left side in N-SG, and on the non-paralyzed side in SG: the third measurement values were small in both cases. [Conclusion] Intrarater reliabilities were high for shoulder horizontal adductor strength measurements using an HHD with a belt for geriatric and stroke patients. Taking the systematic bias into consideration, these findings suggest that the required number of measurements is two.

  18. Shoulder injuries from attacking motion

    NASA Astrophysics Data System (ADS)

    Yanagi, Shigeru; Nishimura, Tetsu; Itoh, Masaru; Wada, Yuhei; Watanabe, Naoki

    1997-03-01

    Sports injuries have bothered professional players. Although many medical doctors try to treat injured players, to prevent sports injuries is more important. Hence, it is required to clear a kinematic mechanism of the sport injuries. A shoulder of volleyball attacker or baseball pitcher is often inured by playing motion. The injuries are mainly caused at the end of long head tendon, which is located in the upper side of scapula. Generally, a muscle and tendon have enough strength against tensile force, however, it seems that they are sometimes defeated by the lateral force. It is imagined that the effect of the lateral force has a possibility of injuring the tendon. If we find the influence of the lateral force on the injured portion, the mechanism of injuries must be cleared. In our research, volleyball attacking motion is taken by high speed video cameras. We analyze the motion as links system and obtain an acceleration of an arm and a shoulder from video image data. The generated force at a shoulder joint is calculated and resolved into the lateral and longitudinal forces. Our final goal is to discuss a possibility that the lateral force causes the injuries.

  19. Relaxin Receptor RXFP1 and RXFP2 Expression in Ligament, Tendon, and Shoulder Joint Capsule of Rats

    PubMed Central

    2016-01-01

    Numerous musculoskeletal disorders are caused by thickened ligament, tendon stiffness, or fibrosis of joint capsule. Relaxin, a peptide hormone, can exert collagenolytic effect on ligamentous and fibrotic tissues. We hypothesized that local injection of relaxin could be used to treat entrapment neuropathy and adhesive capsulitis. Because hormonal effect depends on the receptor of the hormone on the target cell, it is important to confirm the presence of such hormonal receptor at the target tissue before the hormone therapy is initiated. The aim of this study was to determine whether there were relaxin receptors in the ligament, tendon, and joint capsular tissues of rats and to identify the distribution of relaxin receptors in these tissues. Transverse carpal ligaments (TCLs), inguinal ligaments, anterior cruciate ligaments (ACLs), Achilles tendons, and shoulder joint capsules were obtained from male Wistar rats. Western blot analysis was used to identify relaxin receptor isoforms RXFP1 and RXFP2. The distribution of relaxin receptors was determined by immunohistochemical staining. The RXFP1 isoform was found in all tissues examined. The RXFP2 isoform was present in all tissues but the TCLs. Its expression in ACLs tissues was relatively weak compared to that in other tissues. Our results revealed that RXFP1 and RXFP2 were distributed in distinctly different patterns according to the type of tissue (vascular endothelial cells, fibroblast-like cells) they were identified. PMID:27247510

  20. Joint Force Quarterly. Number 25, Summer 2000

    DTIC Science & Technology

    2000-09-01

    than reducing the territorial structure would reverse that trend. But under the status quo, of- ficers also covet the perquisites of serv- ice in the...nically sophisticated. Like other serv- ices , it is undergoing profound changes in force structure, professionalization, and force projection capabilities...R ic ar do M az al an ) 1125 Fishel Pgs 2/24/01 11:31 AM Page 51 ■ J F Q F O R U M despite its tumultuous early history. The nation was wracked

  1. Service Culture and the Joint Force

    DTIC Science & Technology

    2011-03-18

    Joint Chiefs of Staff, 1990 to 2005 (Carlisle Barracks, PA: U.S. Army War College, April 2006), 23. 63 Richard M. Meinhart , “Vice Chairmen of the...reflect the official policy or position of the Department of the Army , Department of Defense, or the U.S. Government. U.S. Army War College...Carlisle Barracks, PA 17013-5050 USAWC CLASS OF 2011 The U.S. Army War College is accredited by the Commission on Higher Education of the Middle

  2. Joint Force Quarterly. Number 12, Summer 1996

    DTIC Science & Technology

    1996-08-01

    War College by Richard A . Chilcoat and Roderick R. Magee II 81 Developing a Strategy for Troubled States by Robert B. Oakley P H O T O C R E D I T S...MG Richard A . Chilcoat, USA ■ U.S. Army War College A . Denis Clift ■ Joint Military Intelligence College Col K.A. Conry, USMC ■ Marine Corps Command...C O A T and R O D E R I C K R. M A G E E I I Major General Richard A . Chilcoat, USA, is 43rd commandant of the U.S. Army War College and

  3. Shoulder Osteoarthritis

    PubMed Central

    2013-01-01

    Osteoarthritis (OA) is the most frequent cause of disability in the USA, affecting up to 32.8% of patients over the age of sixty. Treatment of shoulder OA is often controversial and includes both nonoperative and surgical modalities. Nonoperative modalities should be utilized before operative treatment is considered, particularly for patients with mild-to-moderate OA or when pain and functional limitations are modest despite more advanced radiographic changes. If conservative options fail, surgical treatment should be considered. Although different surgical procedures are available, as in other joints affected by severe OA, the most effective treatment is joint arthroplasty. The aim of this work is to give an overview of the currently available treatments of shoulder OA. PMID:23365745

  4. Enhancing Army Joint Force Headquarters Capabilities

    DTIC Science & Technology

    2010-01-01

    Ad hoc (Army) 2004–2005 MNSTC-I SSTR CENTCOM Ad hoc (Army) 2004-2005 JTF-G8/ DNC /RNC HD/CS NORTHCOM Ad hoc (Army) x 3 2004 JTF-515 SSTR PACOM 2004...AFIC = Armed Forces Inaugural Committee; CENTCOM = Central Command; DNC = Democratic National Committee; EUCOM = European Command; FSSG = Fleet

  5. Effect of increased pushoff during gait on hip joint forces

    PubMed Central

    Lewis, Cara L.; Garibay, Erin J.

    2014-01-01

    Anterior acetabular labral tears and anterior hip pain may result from high anteriorly directed forces from the femur on the acetabulum. While providing more pushoff is known to decrease sagittal plane hip moments, it is unknown if this gait modification also decreases hip joint forces. The purpose of this study was to determine if increasing pushoff decreases hip joint forces. Nine healthy subjects walked on an instrumented force treadmill at 1.25 m/s under two walking conditions. For the natural condition, subjects were instructed to walk as they normally would. For the increased pushoff condition, subjects were instructed to “push more with your foot when you walk”. We collected motion data of markers placed on the subjects’ trunk and lower extremities to capture trunk and leg kinematics and ground reaction force data to determine joint moments. Data were processed in Visual 3D to produce the inverse kinematics and model scaling files. In OpenSim, the generic gait model (Gait2392) was scaled to the subject, and hip joint forces were calculated for the femur on the acetabulum after computing the muscle activations necessary to reproduce the experimental data. The instruction to “push more with your foot when you walk” reduced the maximum hip flexion and extension moment compared to the natural condition. The average reduction in the hip joint forces was 12.5%, 3.2% and 9.6% in the anterior, superior and medial directions respectively and 2.3% for the net resultant force. Increasing pushoff may be an effective gait modification for people with anterior hip pain. PMID:25468661

  6. Effect of increased pushoff during gait on hip joint forces.

    PubMed

    Lewis, Cara L; Garibay, Erin J

    2015-01-02

    Anterior acetabular labral tears and anterior hip pain may result from high anteriorly directed forces from the femur on the acetabulum. While providing more pushoff is known to decrease sagittal plane hip moments, it is unknown if this gait modification also decreases hip joint forces. The purpose of this study was to determine if increasing pushoff decreases hip joint forces. Nine healthy subjects walked on an instrumented force treadmill at 1.25 m/s under two walking conditions. For the natural condition, subjects were instructed to walk as they normally would. For the increased pushoff condition, subjects were instructed to "push more with your foot when you walk". We collected motion data of markers placed on the subjects' trunk and lower extremities to capture trunk and leg kinematics and ground reaction force data to determine joint moments. Data were processed in Visual3D to produce the inverse kinematics and model scaling files. In OpenSim, the generic gait model (Gait2392) was scaled to the subject, and hip joint forces were calculated for the femur on the acetabulum after computing the muscle activations necessary to reproduce the experimental data. The instruction to "push more with your foot when you walk" reduced the maximum hip flexion and extension moment compared to the natural condition. The average reduction in the hip joint forces were 12.5%, 3.2% and 9.6% in the anterior, superior and medial directions respectively and 2.3% for the net resultant force. Increasing pushoff may be an effective gait modification for people with anterior hip pain.

  7. Joint Force Quarterly. Number 3, Winter 1993-94

    DTIC Science & Technology

    1994-01-01

    OMB control number. 1. REPORT DATE 1993 2. REPORT TYPE 3. DATES COVERED 00-00-1993 to 00-00-1993 4. TITLE AND SUBTITLE Joint Force Quarterly...a different practical understand- ing of joint operations. Specialization, for ex- ample, ultimately argues in favor of a com- mand and control system...mean the Navy can or should abandon its classical conflict focus on control of the seas, even if the seas are most likely to be the littorals of the

  8. Joint Force Quarterly. Issue 66, 3rd Quarter 2012

    DTIC Science & Technology

    2012-07-01

    core combat systems are interactive with one another, creating a synergistic outcome and capability rather than providing an additive- segmented tool ...J o i n t F o r c e Q u a r t e r l y issue 66, 3rd Quarter 2012 Achieving Force Resilience Offensive Cyber Joint System Assessments Report...cross-pollination” of students on a large scale. At a joint-minded level, we need to rethink our Service personnel systems , which could enhance the

  9. Effect of core muscle thickness and static or dynamic balance on prone bridge exercise with sling by shoulder joint angle in healthy adults

    PubMed Central

    Park, Mi Hwa; Yu, Jae Ho; Hong, Ji Heon; Kim, Jin Seop; Jung, Sang Woo; Lee, Dong Yeop

    2016-01-01

    [Purpose] To date, core muscle activity detected using ultrasonography during prone bridge exercises has not been reported. Here we investigated the effects of core muscle thickness and balance on sling exercise efficacy by shoulder joint angle in healthy individuals. [Subjects and Methods] Forty-three healthy university students were enrolled in this study. Ultrasonography thickness of external oblique, internal oblique, and transversus abdominis during sling workouts was investigated. Muscle thickness was measured on ultrasonography imaging before and after the experiment. Dynamic balance was tested using a functional reaching test. Static balance was tested using a Tetrax Interactive Balance System. [Results] Different muscle thicknesses were observed during the prone bridge exercise with the shoulder flexed at 60°, 90° or 120°. Shoulder flexion at 60° and 90° in the prone bridge exercise with a sling generated the greatest thickness of most transversus abdominis muscles. Shoulder flexion at 120° in the prone bridge exercise with a sling generated the greatest thickness of most external oblique muscles. [Conclusion] The results suggest that the prone bridge exercise with shoulder joint angle is an effective method of increasing global and local muscle strength. PMID:27134390

  10. Instrumented Bolts Would Measure Shear Forces In Joints

    NASA Technical Reports Server (NTRS)

    Sawyer, James Wayne; Mcwithey, Robert R.

    1994-01-01

    Bolts instrumented with strain gauges used to measure shear forces. Bolts installed in multiple-bolt lap joints to obtain data on distribution of stresses and deformations in and around joints. Strain gauges indicate share of applied load borne by each individual bolt. In original application, bolted panels made of advanced refractory composite materials designed to withstand use at temperatures up to 4,000 degrees F. Also applicable to other joint materials and measurement of shear loads in other connections such as, shear loads on shafts in pulleys or gears.

  11. Joint Force Quarterly. Number 4, Spring 1994

    DTIC Science & Technology

    1994-05-01

    subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE...primary needs of multinational peace operations arise in the areas of command and control , intelli- gence, training, logistics, and force mixes to forge...government for lying about the conduct of the war. Space versus Time Most images of war are linked to destroy- ing an enemy, controlling resources, main

  12. Joint Force Quarterly. Number 26, Autumn 2000

    DTIC Science & Technology

    2001-01-01

    accepted such failures as part of doing business . Since modifications usually meant removing aircraft from flying status, Kenney’s deputy in charge...forced mil-to-mil activities through networking and ventures in collabora- tion with cultural, business , educa- tional, and government organizations in...Kingdom, and the United States. ■ In November 1998, American- owned Cupid Foundations closed its busi - ness in Jamaica after 22 years with a loss of 550

  13. Measurement of Resistive Torques in Major Human Joints

    DTIC Science & Technology

    1979-04-01

    Joints Knee Joint Resistive Torques Hip Joint Resistive Moments Elbow Joint Ankle Joint 20. ABSTRACT (Continue on reverse side if necessary and...applications. The major articulating Joints which are considered are the shoulder, knee, hip, elbow and ankle. Due DD I J 1473 EDITION OF I NOV 65 IS OBSOLETE...47 Force is being applied by means of the GFA on the subject’s lower arm for the elbow joint resistive force and moment data collection

  14. Impairment-Based 3-D Robotic Intervention Improves Upper Extremity Work Area in Chronic Stroke: Targeting Abnormal Joint Torque Coupling With Progressive Shoulder Abduction Loading

    PubMed Central

    Ellis, Michael D.; Sukal-Moulton, Theresa M.; Dewald, Julius P. A.

    2010-01-01

    The implementation of a robotic system (ACT3D) that allowed for a quantitative measurement of abnormal joint torque coupling in chronic stroke survivors and, most importantly, a quantitative means of initiating and progressing an impairment-based intervention, is described. Individuals with chronic moderate to severe stroke (n = 8) participated in this single-group pretest-posttest design study. Subjects were trained over eight weeks by progressively increasing the level of shoulder abduction loading experienced by the participant during reaching repetitions as performance improved. Reaching work area was evaluated pre- and postintervention for ten different shoulder abduction loading levels along with isometric single-joint strength and a qualitative clinical assessment of impairment. There was a significant effect of session (pre versus post) with an increase in reaching work area, despite no change in single-joint strength. This data suggests that specifically targeting the abnormal joint torque coupling impairment through progressive shoulder abduction loading is an effective strategy for improving reaching work area following hemiparetic stroke. Application of robotics, namely, the ACT3D, allowed for quantitative control of the exercise parameters needed to directly target the synergistic coupling impairment. The targeted reduction of abnormal joint torque coupling is likely the key factor explaining the improvements in reaching range of motion achieved with this intervention. PMID:20657711

  15. Knee joint forces during downhill walking with hiking poles.

    PubMed

    Schwameder, H; Roithner, R; Müller, E; Niessen, W; Raschner, C

    1999-12-01

    The aim of this study was to determine external and internal loads on the knee joint during downhill walking with and without hiking poles. Kinematic, kinetic and electromyographic data were collected from eight males during downhill walking on a ramp declined at 25 degrees. Planar knee joint moments and forces were calculated using a quasi-static knee model. The results were analysed for an entire pole-cycle as well as differentiated between single and double support phases and between each step of a pole-cycle. Significant differences between downhill walking with and without hiking poles were observed for peak and average magnitudes of ground reaction force, knee joint moment, and tibiofemoral compressive and shear forces (12-25%). Similar reductions were found in patellofemoral compressive force, the quadriceps tendon force and the activity of the vastus lateralis; however, because of a high variability, these differences were not significant. The reductions seen during downhill walking with hiking poles compared with unsupported downhill walking were caused primarily by the forces applied to the hiking poles and by a change in posture to a more forward leaning position of the upper body, with the effect of reducing the knee moment arm.

  16. Joint Force Interdependence for a Fiscally Constrained Future

    DTIC Science & Technology

    2013-03-01

    Army 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Dr. Richard Meinhart ...Joint Force Interdependence For A Fiscally Constrained Future by Colonel Daniel P. Ray United States Army ...United States Army War College Class of 2013 DISTRIBUTION STATEMENT: A Approved for Public Release Distribution is Unlimited

  17. Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

    PubMed Central

    Migliore, A.; Bizzi, E.; De Lucia, O.; Delle Sedie, A.; Tropea, S.; Bentivegna, M.; Mahmoud, A.; Foti, C.

    2016-01-01

    OBJECTIVES The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet. METHODS An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA. RESULTS Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication. CONCLUSIONS There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient. PMID:27279754

  18. Separated Shoulder

    MedlinePlus

    Separated shoulder Overview By Mayo Clinic Staff A separated shoulder is an injury to the ligaments that hold your collarbone (clavicle) to your shoulder blade. In a mild separated shoulder, the ligaments ...

  19. [Orthopedic treatment of the shoulder joint impairment in patients with rheumatoid arthritis].

    PubMed

    Herasymenko, S I; Babko, A M; Poluliakh, M V; Huzhevs'kyĭ, I V; Herasymenko, A S

    2014-12-01

    Brachial joint affection in patients, suffering rheumatoid arthritis, occupies a third place after such of the elbow and the hand. Due to significant reduction of a freedom degree, caused by inflammation, the upper extremity looses function of active instrument for the items transposition. Volume of surgical treatment of such patients depends on stage of the process. On early stages arthroscopic synovectomy of brachial joint is performed and on the late--endoprosthesis. Late results of the treatment are mainly positive. Satisfactory results are based, predominantly, on raising of activity of general rheumatoid inflammation.

  20. Effect of Resistance Training Maintaining the Joint Angle-torque Profile Using a Haptic-based Machine on Shoulder Internal and External Rotation

    PubMed Central

    Kim, Yeonghun; Lee, Kunwoo; Moon, Jeheon; Koo, Dohoon; Park, Jaewoo; Kim, Kyengnam; Hong, Daehie; Shin, Inshik

    2014-01-01

    [Purpose] The aim of this study was to present an individualized resistance training method to enable exercise while maintaining an exercise load that is set according to an individual’s joint angle-torque using a haptic-based resistance training machine. [Methods] Five participants (machine group) performed individualized shoulder internal and external rotation training with a haptic resistance training machine, while another five participants performed general dumbbell-based shoulder internal and external rotation training for eight weeks. Internal and external rotation powers of subjects were measured using an isokinetic machine before and after training. [Results] The average powers of both shoulder internal and external rotation has been improved after training (25.72%, 13.62%). The improvement in power of external rotation in the machine group was significantly higher than that in the control group. [Conclusion] This study proposes a haptic-based individualized rotator cuff muscle training method. The training protocol maintaining the joint angle-torque profile showed better improvement of shoulder internal/external rotation than dumbbell training. PMID:24764626

  1. Adaptation of the AnyBody™ Musculoskeletal Shoulder Model to the Nonconforming Total Shoulder Arthroplasty Context.

    PubMed

    Sins, Lauranne; Tétreault, Patrice; Hagemeister, Nicola; Nuño, Natalia

    2015-10-01

    Current musculoskeletal inverse dynamics shoulder models have two limitations to use in the context of nonconforming total shoulder arthroplasty (NC-TSA). First, the ball and socket glenohumeral (GH) joint simplification avoids any humeral head translations. Second, there is no contact at the GH joint to compute the contact area and the center of pressure (COP) between the two components of NC-TSA. In this paper, we adapted the AnyBody™ shoulder model by introducing humeral head translations and contact between the two components of an NC-TSA. Abduction in the scapular plane was considered. The main objective of this study was to adapt the AnyBody™ shoulder model to a NC-TSA context and to compare the results of our model (translations, COP, contact area, GH joint reaction forces (GH-JRFs), and muscular forces) with previous numerical, experimental, and clinical studies. Humeral head translations and contact were successfully introduced in our adapted shoulder model with strong support for our findings by previous studies.

  2. Adhesively-Bonded Structural Composite Joint Utilizing Shoulder-Centered Sleeves

    NASA Technical Reports Server (NTRS)

    Lukowski, Florian P., Jr. (Inventor)

    2015-01-01

    A composite joint includes a first member having a groove therein, a second member adjacent to the first member, and a connector member disposed between the second member and the first member. The connector member is received in the groove so as to bias a load path between the first member and the second member from a peripheral portion to a central portion of the connector member.

  3. The influence of patellofemoral joint contact geometry on the modeling of three dimensional patellofemoral joint forces.

    PubMed

    Powers, Christopher M; Chen, Yu-Jen; Scher, Irving; Lee, Thay Q

    2006-01-01

    The purpose of this study was to determine the influence of patellofemoral joint contact geometry on the modeling of three-dimensional patellofemoral joint forces. To achieve this goal, patellofemoral joint reaction forces (PFJRFs) that were measured from an in-vitro cadaveric set-up were compared to PFJRFs estimated from a computer model that did not consider patellofemoral joint contact geometry. Ten cadaver knees were used in this study. Each was mounted on a custom jig that was fixed to an Instron frame. Quadriceps muscle loads were accomplished using a pulley system and weights. The force in the patellar ligament was obtained using a buckle transducer. To quantify the magnitude and direction of the PFJRF, a six-axis load cell was incorporated into the femoral fixation system so that a rigid body assumption could be made. PFJRF data were obtained at 0 degrees , 20 degrees , 40 degrees and 60 degrees of knee flexion. Following in vitro testing, SIMM modeling software was used to develop computational models based on the three-dimensional coordinates (Microscribe digitizer) of individual muscle and patellar ligament force vectors obtained from the cadaver knees. The overall magnitude of the PFJRF estimated from the computer generated models closely matched the direct measurements from the in vitro set-up (Pearson's correlation coefficient, R(2)=0.91, p<0.001). Although the computational model accurately estimated the posteriorly directed forces acting on the joint, some discrepancies were noted in the forces acting in the superior and lateral directions. These differences however, were relatively small when expressed as a total of the overall PFJRF magnitude.

  4. Immediate Effects of Angular Joint Mobilization (a New Concept of Joint Mobilization) on Pain, Range of Motion, and Disability in a Patient with Shoulder Adhesive Capsulitis: A Case Report

    PubMed Central

    Kim, Younghoon; Lee, GyuChang

    2017-01-01

    Patient: Female, 53 Final Diagnosis: Adhesive capsulitis Symptoms: Pain • limited range of motion Medication: None Clinical Procedure: Manual therapy (joint mobilization) Specialty: Physical Therapy Objective: Unusual or unexpected effect of treatment Background: Adhesive capsulitis is a common disabling condition, with reviews reporting up to 5.3% of the population being affected, the burden placed upon individuals and healthcare services may therefore be considered substantial. For recovering the normal extensibility of the capsule in individuals with adhesive capsulitis of the shoulder, passive stretching of the capsule through end-range mobilization has been suggested. Recently, the concept of joint mobilization into angular joint mobilization (AJM), which is rotational joint mobilization with joint axis shift, was proposed. This case report aimed to investigate the immediate effect of AJM on pain, range of motion (ROM), and disability in a patient with shoulder adhesive capsulitis. Case Report: The patient was a 53-year-old woman who was diagnosed with left shoulder adhesive capsulitis. Her left shoulder gradually stiffened, affecting functional activity. The patient attended 12 joint mobilization sessions over a period of six weeks (two times per week). The intervention consisted of rotary oscillations of the left shoulder, which were applied with overpressure and stops before the end of the pathological limit. After intervention, the patient reported 3/100 pain intensity on the visual analogue scale (VAS) (before versus after: 58 versus 3). Active ROM improved by 51° in flexion, 76.4° in abduction, 38.7° in external rotation, and 51.4° in active internal rotation. Passive ROM improved by 49° in flexion, 74.6° in abduction, 39.4° in external rotation, 51.4° in internal rotation. The total shoulder, pain and disability index (SPADI) score improved by 53.9%. Conclusions: The patient reacted positively to AJM, resulting in improved shoulder pain, ROM

  5. Investigating shoulder muscle loading and exerted forces during wall painting tasks: influence of gender, work height and paint tool design.

    PubMed

    Rosati, Patricia M; Chopp, Jaclyn N; Dickerson, Clark R

    2014-07-01

    The task of wall painting produces considerable risk to the workers, both male and female, primarily in the development of upper extremity musculoskeletal disorders. Insufficient information is currently available regarding the potential benefits of using different paint roller designs or the possible adverse effects of painting at different work heights. The aim of this study was to investigate the influence of gender, work height, and paint tool design on shoulder muscle activity and exerted forces during wall painting. Ten young adults, five male and five female, were recruited to perform simulated wall painting at three different work heights with three different paint roller designs while upper extremity muscle activity and horizontal push force were recorded. Results demonstrated that for female participants, significantly greater total average (p = 0.007) and integrated (p = 0.047) muscle activity was present while using the conventional and curly flex paint roller designs compared to the proposed design in which the load was distributed between both hands. Additionally, for both genders, the high working height imposed greater muscular demands compared to middle and low heights. These findings suggest that, if possible, avoid painting at extreme heights (low or high) and that for female painters, consider a roller that requires the use of two hands; this will reduce fatigue onset and subsequently mitigate potential musculoskeletal shoulder injury risks.

  6. Joint Command and Control of Cyber Operations: The Joint Force Cyber Component Command (JFCCC)

    DTIC Science & Technology

    2012-05-04

    relies so heavily on complex command and control systems and interconnectivity in general, cyber warfare has become a serious topic of interest at the...defensive cyber warfare into current and future operations and plans. In particular, Joint Task Force (JTF) Commanders must develop an optimum method to

  7. Shoulder proprioception in baseball pitchers.

    PubMed

    Safran, M R; Borsa, P A; Lephart, S M; Fu, F H; Warner, J J

    2001-01-01

    We examined proprioceptive differences between the dominant and nondominant shoulders of 21 collegiate baseball pitchers without a history of shoulder instability or surgery. A proprioceptive testing device was used to measure kinesthesia and joint position sense. Joint position sense was significantly (P =.05) more accurate in the nondominant shoulder than in the dominant shoulder when starting at 75% of maximal external rotation and moving into internal rotation. There were no significant differences for proprioception in the other measured positions or with kinesthesia testing. Six pitchers with recent shoulder pain had a significant (P =.04) kinesthetic deficit in the symptomatic dominant shoulder compared with the asymptomatic shoulder, as measured in neutral rotation moving into internal rotation. The net effect of training, exercise-induced laxity, and increased external rotation in baseball pitchers does not affect proprioception, although shoulder pain, possibly due to rotator cuff inflammation or tendinitis, is associated with reduced kinesthetic sensation.

  8. Multibody system of the upper limb including a reverse shoulder prosthesis.

    PubMed

    Quental, C; Folgado, J; Ambrósio, J; Monteiro, J

    2013-11-01

    The reverse shoulder replacement, recommended for the treatment of several shoulder pathologies such as cuff tear arthropathy and fractures in elderly people, changes the biomechanics of the shoulder when compared to the normal anatomy. Although several musculoskeletal models of the upper limb have been presented to study the shoulder joint, only a few of them focus on the biomechanics of the reverse shoulder. This work presents a biomechanical model of the upper limb, including a reverse shoulder prosthesis, to evaluate the impact of the variation of the joint geometry and position on the biomechanical function of the shoulder. The biomechanical model of the reverse shoulder is based on a musculoskeletal model of the upper limb, which is modified to account for the properties of the DELTA® reverse prosthesis. Considering two biomechanical models, which simulate the anatomical and reverse shoulder joints, the changes in muscle lengths, muscle moment arms, and muscle and joint reaction forces are evaluated. The muscle force sharing problem is solved for motions of unloaded abduction in the coronal plane and unloaded anterior flexion in the sagittal plane, acquired using video-imaging, through the minimization of an objective function related to muscle metabolic energy consumption. After the replacement of the shoulder joint, significant changes in the length of the pectoralis major, latissimus dorsi, deltoid, teres major, teres minor, coracobrachialis, and biceps brachii muscles are observed for a reference position considered for the upper limb. The shortening of the teres major and teres minor is the most critical since they become unable to produce active force in this position. Substantial changes of muscle moment arms are also observed, which are consistent with the literature. As expected, there is a significant increase of the deltoid moment arms and more fibers are able to elevate the arm. The solutions to the muscle force sharing problem support the

  9. Integration of Special Operations Forces into the Joint Targeting Process

    DTIC Science & Technology

    2003-01-01

    INTEGRATION OF SPECIAL OPERATIONS FORCES INTO THE JOINT TARGETING PROCESS A thesis presented to the Faculty of the U. S . Army Command and General...B. S ., Texas A&M University, College Station, Texas, 1991 Fort Leavenworth, Kansas 2003 Approved for public release; distribution is unlimited...CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR( S ) Hester, Johnny, L 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7

  10. Joint Concept Development and Experimentation: A Force Development Perspective

    DTIC Science & Technology

    2012-02-01

    Defence R& D Canada Centre for Operational Research and Analysis Warfare Centre Science Team Canadian Forces Warfare Centre Joint Concept...Warfare Centre Sciences Team Lead DRDC CORA Defence R& D Canada – CORA Technical Memorandum DRDC CORA TM 2012-036 February 2012...Scientist, DRDC CORA Defence R& D Canada – Centre for Operational Research and Analysis (CORA) © Her Majesty the Queen in Right of Canada, as

  11. Expanding the MEU(SOC) Joint Task Force Enabler Concept

    DTIC Science & Technology

    1998-05-28

    concept. 2 The influential twentieth-century linguistic philosopher Ludwig Wittgenstein argued that real understanding rests on the precise use...of language and universally agreed upon meanings. Without clarity and common understanding, Wittgenstein observed, we can never really communicate... Wittgenstein anticipated when we don’t share a common understanding of what a term means. The Joint Task Force Enabler is potentially a critical concept, both

  12. Physical examination of the shoulder.

    PubMed

    King, Joseph J; Wright, Thomas W

    2014-10-01

    This article summarizes the overall assessment of the shoulder joint and seeks to help direct clinicians to diagnose shoulder pathology using standard and specific physical examinations. The history and standard examination can prompt the examiner to focus on specific tests to further evaluate the shoulder and limit the differential diagnoses. An appropriate and directed shoulder physical examination allows the clinician to focus on further diagnostic strategies and treatment options for the patient.

  13. Avulsive axillary artery injury in reverse total shoulder arthroplasty.

    PubMed

    Wingert, Nathaniel C; Beck, John D; Harter, G Dean

    2014-01-01

    In addition to neurologic injuries such as peripheral nerve palsy, axillary vessel injury should be recognized as a possible complication of reverse total shoulder arthroplasty. Limb lengthening associated with Grammont-type reverse total shoulder arthroplasty places tension across the brachial plexus and axillary vessels and may contribute to observed injuries. The Grammont-type reverse total shoulder arthroplasty prosthesis reverses the shoulder ball and socket, shifts the shoulder center of rotation distal and medial, and lengthens the arm. This alteration of native anatomy converts shearing to compressive glenohumeral joint forces while augmenting and tensioning the deltoid lever arm. Joint stability is enhanced; shoulder elevation is enabled in the rotator cuff–deficient shoulder. Arm lengthening associated with reverse total shoulder arthroplasty places a longitudinal strain on the brachial plexus and axillary vessels. Peripheral nerve palsies and other neurologic complications of reverse total shoulder arthroplasty have been documented. The authors describe a patient with rotator cuff tear arthropathy and a history of radioulnar synostosis who underwent reverse total shoulder arthroplasty complicated by intraoperative injury to the axillary artery and postoperative radial, ulnar, and musculocutaneous nerve palsies. Following a seemingly unremarkable placement of reverse shoulder components, brisk arterial bleeding was encountered while approximating the incised subscapularis tendon in preparation for wound closure. Further exploration revealed an avulsive-type injury of the axillary artery. After an unsuccessful attempt at primary repair, a synthetic arterial bypass graft was placed. Reperfusion of the right upper extremity was achieved and has been maintained to date. Postoperative clinical examination and electromyographic studies confirmed ongoing radial, ulnar, and musculocutaneous neuropathies.

  14. Influence of joint models on lower-limb musculo-tendon forces and three-dimensional joint reaction forces during gait.

    PubMed

    Dumas, Raphaël; Moissenet, Florent; Gasparutto, Xavier; Cheze, Laurence

    2012-02-01

    Several three-dimensional (3D) lower-limb musculo-skeletal models have been developed for gait analysis and different hip, knee and ankle joint models have been considered in the literature. Conversely to the influence of the musculo-tendon geometry, the influence of the joint models--i.e. number of degrees of freedom and passive joint moments--on the estimated musculo-tendon forces and 3D joint reaction forces has not been extensively examined. In this paper musculo-tendon forces and 3D joint reaction forces have been estimated for one subject and one gait cycle with nine variations of a musculoskeletal model and outputs have been compared to measured electromyographic signals and knee joint contact forces. The model outputs are generally in line with the measured signals. However, the 3D joint reaction forces were higher than published values and the contact forces measured for the subject. The results of this study show that, with more degrees of freedom in the model, the musculo-tendon forces and the 3D joint reaction forces tend to increase but with some redistribution between the muscles. In addition, when taking into account passive joint moments, the 3D joint reaction forces tend to decrease during the stance phase and increase during the swing phase. Although further investigations are needed, a five-degree-of-freedom lower-limb musculo-skeletal model with some angle-dependent joint coupling and stiffness seems to provide satisfactory musculo-tendon forces and 3D joint reaction forces.

  15. Relationship Between the Range of Motion and Isometric Strength of Elbow and Shoulder Joints and Ball Velocity in Women Team Handball Players.

    PubMed

    Schwesig, René; Hermassi, Souhail; Wagner, Herbert; Fischer, David; Fieseler, Georg; Molitor, Thomas; Delank, Karl-Stefan

    2016-12-01

    Schwesig, R, Hermassi, S, Wagner, H, Fischer, D, Fieseler, G, Molitor, T, and Delank, K-S. Relationship between the range of motion and isometric strength of elbow and shoulder joints and ball velocity in women team handball players. J Strength Cond Res 30(12): 3428-3435, 2016-The aims of this study were to investigate relationships between isometric strength and range of motion (ROM) of shoulder and elbow joints and compare 2 different team handball throwing techniques in women team handball. Twenty highly experienced women team handball players (age: 20.7 ± 2.9 years; body mass: 68.4 ± 6.0 kg; and height: 1.74 ± 0.06 m) participated in this study. The isometric strength (hand-held dynamometer) and ROM (goniometer) of shoulder and elbow joints were measured at the beginning of the preseasonal training. After clinical examination, the subjects performed 3 standing throws with run-up (10 m) and 3 jump throws over a hurdle (0.20 m). The mean ball velocity was calculated from 3 attempts and measured using a radar gun. The results showed that the ball velocity of the standing throw with run-up (vST) was significantly higher than that of the jump throw (vJT) (25.5 ± 1.56 vs. 23.2 ± 1.31 m·s; p < 0.001). Therefore, significant playing position effects (p = 0.021) were only found for ST. Goalkeepers (n = 2) had the lowest (22.6 ± 0.04 m·s) and backcourt players (n = 9), the highest (26.1 ± 1.36 m·s) vST. The retroversion strength in the shoulder was the only parameter with relevant correlations to both throws (vST: r = 0.52, and vJT: r = 0.43). Other relevant relationships to vJT were found for adduction strength shoulder (r = 0.55) and ROM flexion elbow (r = -0.54). The vST was only correlated to the glenohumeral internal rotation deficit. As a consequence, strength is more important than the ROM, and in addition to this, the shoulder, compared with the elbow, has a greater influence on the vST in highly experienced women team handball players.

  16. Pathomechanics of the throwing shoulder.

    PubMed

    Kibler, W Ben; Thomas, Stephen J

    2012-03-01

    Many anatomic, physiological, and biomechanical alterations have been observed in overhead athletes who present with painful shoulders. This is probably due to the complex kinetic chain mechanics required in the overhead throwing or serving motion. Any alteration along the kinetic chain can result in deficits in force production or increase in joint loads in other parts of the chain. The "disabled throwing shoulder" (DTS) is a general term that describes the limitations in function that exist in symptomatic overhead athletes. DTS typically results from a "cascade to injury" with alterations in the kinetic chain. Evaluation of athletes with the DTS should include examination of the local and distant anatomic injuries and screening for physiological (muscle inflexibilities, weakness, or imbalances) or biomechanical (motions, positions) alterations.

  17. The Disestablishment of U.S. Joint Forces Command: A Step Backward in "Jointness"

    DTIC Science & Technology

    2011-06-01

    States Army ABSTRACT The Unified Command Plan established the United States Joint Forces Command (USJFCOM) as a separate and distinct...doctrine, training, tactics, and equipment.”3 One of the premier Army visionaries of the post-Vietnam era, Donn Starry, also recognized that “change is...files/College/F_Publications/occPapers/occ-paper_18-en.pdf (accessed 20 November 2010). 4 U.S. Army War College, Selected Readings, Volume II, Course

  18. The Joint Operating Environment (JOE): Challenges and Implications for the Future Joint Force

    DTIC Science & Technology

    2008-11-25

    be called on to protect our national interests. Merely sustaining the health of the Joint Force, never mind adapting and transforming, is far more...very powerful motives prevent us from doing so – security, honour, and self interest. And we were not the first to act in this way. Far from it.” 4...deep understanding of the enemy – his culture, history, geography, religious and ideological motivations , and particularly the huge differences in

  19. Revisiting the Force-Joint Angle Relationship After Eccentric Exercise.

    PubMed

    Welsh, Molly C; Allen, David L; Batliner, Matthew E; Byrnes, William C

    2015-12-01

    The purpose of this study was to evaluate force-angle curve fitting techniques pre-eccentric exercise, quantify changes in curve characteristics postexercise, and examine the relationship between curve changes and markers of muscle damage. Fourteen males unaccustomed to eccentric exercise performed 60 eccentric muscle actions of the elbow flexors. Maximal voluntary isometric force was measured throughout a range of angles pre- (Pre1 and Pre2), immediately post (IP), and 1, 2, 4, and 7 days postexercise. Force-angle curves for each visit were constructed using second-order polynomials. Changes in curve characteristics (optimal angle, peak force, curve height), range of motion, soreness, and creatine kinase activity were quantified. Optimal joint angle and force at optimal angle were significantly correlated from Pre1 to Pre2 (ICC = 0.821 and 0.979, respectively). Optimal angle was significantly right shifted (p = 0.035) by 10.4 ± 12.9° from Pre2 to IP and was restored by 1 day post exercise. Interestingly, the r value for curve fit was significantly decreased (p < 0.001) from Pre2 (r = 0.896) to IP (r = 0.802) and 1 day post exercise (r = 0.750). Curve height was significantly decreased (39%) IP and restored to pre-exercise height by 4 days postexercise. There was no correlation between optimal angle or curve height and other damage markers. In conclusion, force-angle relationships can be accurately described using second-order polynomials. After eccentric exercise, the force-angle curve is flattened and shifted (downward and rightward), but these changes are not correlated to other markers of muscle damage. Changes in the force-angle relationship are multifaceted, but determining the physiological significance of these changes requires further investigation.

  20. Individual muscle contributions to the axial knee joint contact force during normal walking.

    PubMed

    Sasaki, Kotaro; Neptune, Richard R

    2010-10-19

    Muscles are significant contributors to the high joint forces developed in the knee during human walking. Not only do muscles contribute to the knee joint forces by acting to compress the joint, but they also develop joint forces indirectly through their contributions to the ground reaction forces via dynamic coupling. Thus, muscles can have significant contributions to forces at joints they do not span. However, few studies have investigated how the major lower-limb muscles contribute to the knee joint contact forces during walking. The goal of this study was to use a muscle-actuated forward dynamics simulation of walking to identify how individual muscles contribute to the axial tibio-femoral joint force. The simulation results showed that the vastii muscles are the primary contributors to the axial joint force in early stance while the gastrocnemius is the primary contributor in late stance. The tibio-femoral joint force generated by these muscles was at times greater than the muscle forces themselves. Muscles that do not cross the knee joint (e.g., the gluteus maximus and soleus) also have significant contributions to the tibio-femoral joint force through their contributions to the ground reaction forces. Further, small changes in walking kinematics (e.g., knee flexion angle) can have a significant effect on the magnitude of the knee joint forces. Thus, altering walking mechanics and muscle coordination patterns to utilize muscle groups that perform the same biomechanical function, yet contribute less to the knee joint forces may be an effective way to reduce knee joint loading during walking.

  1. Improving anterior deltoid activity in a musculoskeletal shoulder model - an analysis of the torque-feasible space at the sternoclavicular joint.

    PubMed

    Ingram, David; Engelhardt, Christoph; Farron, Alain; Terrier, Alexandre; Müllhaupt, Philippe

    2016-01-01

    Modelling the shoulder's musculature is challenging given its mechanical and geometric complexity. The use of the ideal fibre model to represent a muscle's line of action cannot always faithfully represent the mechanical effect of each muscle, leading to considerable differences between model-estimated and in vivo measured muscle activity. While the musculo-tendon force coordination problem has been extensively analysed in terms of the cost function, only few works have investigated the existence and sensitivity of solutions to fibre topology. The goal of this paper is to present an analysis of the solution set using the concepts of torque-feasible space (TFS) and wrench-feasible space (WFS) from cable-driven robotics. A shoulder model is presented and a simple musculo-tendon force coordination problem is defined. The ideal fibre model for representing muscles is reviewed and the TFS and WFS are defined, leading to the necessary and sufficient conditions for the existence of a solution. The shoulder model's TFS is analysed to explain the lack of anterior deltoid (DLTa) activity. Based on the analysis, a modification of the model's muscle fibre geometry is proposed. The performance with and without the modification is assessed by solving the musculo-tendon force coordination problem for quasi-static abduction in the scapular plane. After the proposed modification, the DLTa reaches 20% of activation.

  2. Questions and Answers About Shoulder Problems

    MedlinePlus

    ... the dislocation using a traditional open surgery approach. Separation A shoulder separation occurs where the collarbone (clavicle) meets the shoulder ... acromioclavicular or AC joint) are signs that a separation may have occurred. Diagnosis. Doctors may diagnose a ...

  3. Shoulder Injuries in US Astronauts Related to EVA Suit Design

    NASA Technical Reports Server (NTRS)

    Scheuring, R. A.; McCulloch, P.; Van Baalen, Mary; Minard, Charles; Watson, Richard; Blatt, T.

    2011-01-01

    Introduction: For every one hour spent performing extravehicular activity (EVA) in space, astronauts in the US space program spend approximately six to ten hours training in the EVA spacesuit at NASA-Johnson Space Center's Neutral Buoyancy Lab (NBL). In 1997, NASA introduced the planar hard upper torso (HUT) EVA spacesuit which subsequently replaced the existing pivoted HUT. An extra joint in the pivoted shoulder allows increased mobility but also increased complexity. Over the next decade a number of astronauts developed shoulder problems requiring surgical intervention, many of whom performed EVA training in the NBL. This study investigated whether changing HUT designs led to shoulder injuries requiring surgical repair. Methods: US astronaut EVA training data and spacesuit design employed were analyzed from the NBL data. Shoulder surgery data was acquired from the medical record database, and causal mechanisms were obtained from personal interviews Analysis of the individual HUT designs was performed as it related to normal shoulder biomechanics. Results: To date, 23 US astronauts have required 25 shoulder surgeries. Approximately 48% (11/23) directly attributed their injury to training in the planar HUT, whereas none attributed their injury to training in the pivoted HUT. The planar HUT design limits shoulder abduction to 90 degrees compared to approximately 120 degrees in the pivoted HUT. The planar HUT also forces the shoulder into a forward flexed position requiring active retraction and extension to increase abduction beyond 90 degrees. Discussion: Multiple factors are associated with mechanisms leading to shoulder injury requiring surgical repair. Limitations to normal shoulder mechanics, suit fit, donning/doffing, body position, pre-existing injury, tool weight and configuration, age, in-suit activity, and HUT design have all been identified as potential sources of injury. Conclusion: Crewmembers with pre-existing or current shoulder injuries or certain

  4. Numerical modelling of the shoulder for clinical applications.

    PubMed

    Favre, Philippe; Snedeker, Jess G; Gerber, Christian

    2009-05-28

    Research activity involving numerical models of the shoulder is dramatically increasing, driven by growing rates of injury and the need to better understand shoulder joint pathologies to develop therapeutic strategies. Based on the type of clinical question they can address, existing models can be broadly categorized into three groups: (i) rigid body models that can simulate kinematics, collisions between entities or wrapping of the muscles over the bones, and which have been used to investigate joint kinematics and ergonomics, and are often coupled with (ii) muscle force estimation techniques, consisting mainly of optimization methods and electromyography-driven models, to simulate muscular action and joint reaction forces to address issues in joint stability, muscular rehabilitation or muscle transfer, and (iii) deformable models that account for stress-strain distributions in the component structures to study articular degeneration, implant failure or muscle/tendon/bone integrity. The state of the art in numerical modelling of the shoulder is reviewed, and the advantages, limitations and potential clinical applications of these modelling approaches are critically discussed. This review concentrates primarily on muscle force estimation modelling, with emphasis on a novel muscle recruitment paradigm, compared with traditionally applied optimization methods. Finally, the necessary benchmarks for validating shoulder models, the emerging technologies that will enable further advances and the future challenges in the field are described.

  5. Shoulder osteoarthritis: diagnosis and management.

    PubMed

    Millett, Peter J; Gobezie, Reuben; Boykin, Robert E

    2008-09-01

    Osteoarthritis of the shoulder is a gradual wearing of the articular cartilage that leads to pain and stiffness. As the joint surface degenerates, the subchondral bone remodels, losing its sphericity and congruity. The joint capsule also becomes thickened, leading to further loss of shoulder rotation. This painful condition is a growing problem in the aging population. In most cases, diagnosis of degenerative joint disease of the shoulder can be made with careful history, physical examination, and radiography. The symptoms and degree of shoulder arthritis visible on radiography determine the best treatment option. Mild degenerative joint disease can be treated with physical therapy and over-the-counter anti-inflammatory medications such as acetaminophen or nonsteroidal anti-inflammatory drugs. More advanced cases of osteoarthritis that are refractory to nonoperative management can be managed with corticosteroid injections. In severe cases, surgery is indicated. Surgical options include arthroscopic debridement, arthroscopic capsular release, and, in the most severe instances, hemiarthroplasty or total shoulder arthroplasty.

  6. Concentric and eccentric shoulder rehabilitation biomechanics.

    PubMed

    Kohles, S S; Gregorczyk, K N; Phillips, T C; Brody, L T; Orwin, I F; Vanderby, R

    2007-04-01

    The use of an impulse-momentum (IM) exercise technique was investigated for end-stage shoulder rehabilitation. The objectives of this study were to: (a) quantify the net shoulder joint forces and moments while using an IM system and (b) test the influence of gender and muscle loading type (concentric or eccentric) on kinetic and kinematic parameters. Fourteen healthy adults (eight males, six females) performed a repeated measures experiment on an instrumented device utilizing a cabled shuttle system. While maintaining 90 degrees of shoulder abduction and 90 degrees of elbow flexion, the subjects externally rotated their upper arm from 0 degrees to 90 degrees (concentric acceleration) and then internally rotated their upper arm back from 90 degrees to the 0 degrees position (eccentric deceleration). Shoulder joint forces and moments as well as rotational work and power were calculated using inverse dynamics (free-body forces and moments calculated at intersegmental joint centres). Overall concentric peak forces and moments were greater than eccentric peak forces and moments (P < 0.0001). Joint forces and moments reached a maximum during the initial phase of concentric loading (0 degrees to 45 degrees) compared with any other rotational position in the loading cycle (concentric 45 degrees to 90 degrees or eccentric 90 degrees to 0 degrees). The results also indicate that males experienced higher (P < 0.0001) average resultant peak joint forces (concentric 0 degrees to 45 degrees = 108.0 N and eccentric 90 degrees to 45 degrees = 87.2 N) than females (concentric 0 degrees to 45 degrees = 74.7 N and eccentric 45 degrees to 0 degrees = 56.0 N). In addition, males experienced higher (P < 0.0001) average resultant peak joint moments (concentric 0 degrees to 45 degrees = 30.4 N m and eccentric 45 degrees to 0 degrees = 21.0 N m) than females (concentric 0 degrees to 45 degrees = 19.7 N m and eccentric 45 degrees to 0 degrees = 12.8 N m).

  7. Is it possible to reduce the knee joint compression force during level walking with hiking poles?

    PubMed

    Jensen, S B; Henriksen, M; Aaboe, J; Hansen, L; Simonsen, E B; Alkjaer, T

    2011-12-01

    Walking with hiking poles has become a popular way of exercising. Walking with poles is advocated as a physical activity that significantly reduces the loading of the hip, knee and ankle joints. We have previously observed that pole walking does not lead to a reduction of the load on the knee joint. However, it is unclear whether an increased force transmitted through the poles can reduce the load on the knee joint. Thus, the purpose of the present study was to investigate if an increased load transmitted through the arms to the poles could reduce the knee joint compression force during level walking with poles. We hypothesized that an increased pole force would result in a reduction of the knee joint compression force. Gait analyses from 10 healthy subjects walking with poles were obtained. The pole force was measured simultaneously during the gait analyses. The knee joint compression forces were estimated by using a biomechanical knee joint model. The results showed that the subjects were able to increase the pole force by 2.4 times the normal pole force. However, this did not lead to a reduction in the knee joint compressive force and we rejected our hypothesis. In conclusion, the use of poles during level walking does not seem to reduce knee joint compressive loads. However, it is possible that the use of poles in other populations (e.g. osteoarthritis patients) and in terrain would unload the knee joint. This should be investigated in the future.

  8. The Standing Joint Force Headquarters Plan-Does It Go Far Enough?

    DTIC Science & Technology

    2010-07-26

    humanitarian relief effort in Bangladesh following Cyclone Marian, the PACOM DJTFAC deployed in support of the III MEF. A successful relief operation...Putnam’s Sons, 2002. 67 Cole, Ronald H., “Grenada, Panama, and Haiti : Joint Operational Reform,” Joint Forces Quarterly, Autumn/Winter 1998-99...2002. Smith, Matthew , Major (USAF), “Successfully Developing Future Joint Leaders,” Norfolk, VA: Joint Forces Staff College, 2005. Stewart

  9. Shoulder muscle activity and function in common shoulder rehabilitation exercises.

    PubMed

    Escamilla, Rafael F; Yamashiro, Kyle; Paulos, Lonnie; Andrews, James R

    2009-01-01

    The rotator cuff performs multiple functions during shoulder exercises, including glenohumeral abduction, external rotation (ER) and internal rotation (IR). The rotator cuff also stabilizes the glenohumeral joint and controls humeral head translations. The infraspinatus and subscapularis have significant roles in scapular plane abduction (scaption), generating forces that are two to three times greater than supraspinatus force. However, the supraspinatus still remains a more effective shoulder abductor because of its more effective moment arm. Both the deltoids and rotator cuff provide significant abduction torque, with an estimated contribution up to 35-65% by the middle deltoid, 30% by the subscapularis, 25% by the supraspinatus, 10% by the infraspinatus and 2% by the anterior deltoid. During abduction, middle deltoid force has been estimated to be 434 N, followed by 323 N from the anterior deltoid, 283 N from the subscapularis, 205 N from the infraspinatus, and 117 N from the supraspinatus. These forces are generated not only to abduct the shoulder but also to stabilize the joint and neutralize the antagonistic effects of undesirable actions. Relatively high force from the rotator cuff not only helps abduct the shoulder but also neutralizes the superior directed force generated by the deltoids at lower abduction angles. Even though anterior deltoid force is relatively high, its ability to abduct the shoulder is low due to a very small moment arm, especially at low abduction angles. The deltoids are more effective abductors at higher abduction angles while the rotator cuff muscles are more effective abductors at lower abduction angles. During maximum humeral elevation the scapula normally upwardly rotates 45-55 degrees, posterior tilts 20-40 degrees and externally rotates 15-35 degrees. The scapular muscles are important during humeral elevation because they cause these motions, especially the serratus anterior, which contributes to scapular upward rotation

  10. Sleep position and shoulder pain.

    PubMed

    Zenian, John

    2010-04-01

    The overuse theory for musculoskeletal joint pain cannot explain adequately the occurrence of shoulder pain in those who do not engage in activities that involve repeated and stressful use of the shoulder since the percentage of the painful right shoulders usually does not match the percentage of dominant right arms in such individuals. An alternative hypothesis is presented to propose that shoulder pain is caused by postural immobility in the decubitus or side position during sleep. Prolonged pressure on the shoulder caused by the weight of the thorax can produce enough damage to cause subsequent shoulder pain. In order to test this hypothesis, a preliminary study was carried out to compare the laterality of shoulder pain with the laterality of sleep position. The calculated laterality ratios for sleep position and shoulder pain were found to be strikingly similar, suggesting a causal relationship between the two phenomena. However, the prevalence of shoulder pain in the general population was found to be smaller than the percentage of the time people would spend sleeping in the decubitus position. This discrepancy could be explained by the idea that in order for shoulder pain to develop subjects may have to spend longer times in the same decubitus position before changing to another position than the average person would. Additional evidence from published clinical studies also supports the postural theory of shoulder pain. More studies can be done to test this hypothesis by focusing on the sleep habits of patients with shoulder pain. According to the present hypothesis shoulder pain should for the most part occur on the side that the patient preferred to sleep on before the onset of shoulder pain. The postural theory of shoulder pain provides the possibility for a new and noninvasive method to treat shoulder pain by the modification of posture during sleep.

  11. Soft tissue balance changes depending on joint distraction force in total knee arthroplasty.

    PubMed

    Nagai, Kanto; Muratsu, Hirotsugu; Matsumoto, Tomoyuki; Miya, Hidetoshi; Kuroda, Ryosuke; Kurosaka, Masahiro

    2014-03-01

    The influence of joint distraction force on intraoperative soft tissue balance was evaluated using Offset Repo-Tensor® for 78 knees that underwent primary posterior-stabilized total knee arthroplasty. The joint center gap and varus ligament balance were measured between osteotomized surfaces using 20, 40 and 60 lbs of joint distraction force. These values were significantly increased at extension and flexion as the distraction force increased. Furthermore, lateral compartment stiffness was significantly lower than medial compartment stiffness. Thus, larger joint distraction forces led to larger varus ligament balance and joint center gap, because of the difference in soft tissue stiffness between lateral and medial compartments. These findings indicate the importance of the strength of joint distraction force in the assessment of soft tissue balance, especially when using gap-balancing technique.

  12. Motor control hierarchy in joint action that involves bimanual force production

    PubMed Central

    Masumoto, Junya

    2015-01-01

    The concept of hierarchical motor control has been viewed as a means of progressively decreasing the number of variables manipulated by each higher control level. We tested the hypothesis that turning an individual bimanual force-production task into a joint (two-participant) force-production task would lead to positive correlation between forces produced by the two hands of the individual participant (symmetric strategy) to enable negative correlation between forces produced by two participants (complementary strategy). The present study consisted of individual and joint tasks that involved both unimanual and bimanual conditions. In the joint task, 10 pairs of participants produced periodic isometric forces, such that the sum of forces that they produced matched a target force cycling between 5% and 10% of maximum voluntary contraction at 1 Hz. In the individual task, individuals attempted to match the same target force. In the joint bimanual condition, the two hands of each participant adopted a symmetric strategy of force, whereas the two participants adopted a complementary strategy of force, highlighting that the bimanual action behaved as a low level of a hierarchy, whereas the joint action behaved as an upper level. The complementary force production was greater interpersonally than intrapersonally. However, whereas the coherence was highest at 1 Hz in all conditions, the frequency synchrony was stronger intrapersonally than interpersonally. Moreover, whereas the bimanual action exhibited a smaller error and variability of force than the unimanual action, the joint action exhibited a less-variable interval and force than the individual action. PMID:25904710

  13. Motor control hierarchy in joint action that involves bimanual force production.

    PubMed

    Masumoto, Junya; Inui, Nobuyuki

    2015-06-01

    The concept of hierarchical motor control has been viewed as a means of progressively decreasing the number of variables manipulated by each higher control level. We tested the hypothesis that turning an individual bimanual force-production task into a joint (two-participant) force-production task would lead to positive correlation between forces produced by the two hands of the individual participant (symmetric strategy) to enable negative correlation between forces produced by two participants (complementary strategy). The present study consisted of individual and joint tasks that involved both unimanual and bimanual conditions. In the joint task, 10 pairs of participants produced periodic isometric forces, such that the sum of forces that they produced matched a target force cycling between 5% and 10% of maximum voluntary contraction at 1 Hz. In the individual task, individuals attempted to match the same target force. In the joint bimanual condition, the two hands of each participant adopted a symmetric strategy of force, whereas the two participants adopted a complementary strategy of force, highlighting that the bimanual action behaved as a low level of a hierarchy, whereas the joint action behaved as an upper level. The complementary force production was greater interpersonally than intrapersonally. However, whereas the coherence was highest at 1 Hz in all conditions, the frequency synchrony was stronger intrapersonally than interpersonally. Moreover, whereas the bimanual action exhibited a smaller error and variability of force than the unimanual action, the joint action exhibited a less-variable interval and force than the individual action.

  14. Frozen shoulder

    MedlinePlus

    ... cut) by bringing the shoulder through a full range of motion. Arthroscopic surgery can also be used to cut ... if you develop shoulder pain that limits your range of motion for an extended period. People who have diabetes ...

  15. Shoulder Fractures

    MedlinePlus

    ... Journal of Hand Surgery (JHS) Home Anatomy Shoulder Fractures Email to a friend * required fields From * To * ... create difficulty with its function. Types of Shoulder Fractures The type of fracture varies by age. Most ...

  16. Patellofemoral joint compression forces in backward and forward running.

    PubMed

    Roos, Paulien E; Barton, Nick; van Deursen, Robert W M

    2012-06-01

    Patellofemoral pain (PFP) is a common injury and increased patellofemoral joint compression forces (PFJCF) may aggravate symptoms. Backward running (BR) has been suggested for exercise with reduced PFJCF. The aims of this study were to (1) investigate if BR had reduced peak PFJCF compared to forward running (FR) at the same speed, and (2) if PFJCF was reduced in BR, to investigate which biomechanical parameters explained this. It was hypothesized that (1) PFJCF would be lower in BR, and (2) that this would coincide with a reduced peak knee moment caused by altered ground reaction forces (GRFs). Twenty healthy subjects ran in forward and backward directions at consistent speed. Kinematic and ground reaction force data were collected; inverse dynamic and PFJCF analyses were performed. PFJCF were higher in FR than BR (4.5±1.5; 3.4±1.4BW; p<0.01). The majority of this difference (93.1%) was predicted by increased knee moments in FR compared to BR (157±54; 124±51 Nm; p<0.01). 54.8% of differences in knee moments could be predicted by the magnitude of the GRF (2.3±0.3; 2.4±0.2BW), knee flexion angle (44±6; 41±7) and center of pressure location on the foot (25±11; 12±6%) at time of peak knee moment. Results were not consistent in all subjects. It was concluded that BR had reduced PFJCF compared to FR. This was caused by an increased knee moment, due to differences in magnitude and location of the GRF vector relative to the knee. BR can therefore be used to exercise with decreased PFJCF.

  17. Patellofemoral joint compression forces in backward and forward running

    PubMed Central

    Roos, Paulien E.; Barton, Nick; van Deursen, Robert W.M.

    2012-01-01

    Patellofemoral pain (PFP) is a common injury and increased patellofemoral joint compression forces (PFJCF) may aggravate symptoms. Backward running (BR) has been suggested for exercise with reduced PFJCF. The aims of this study were to (1) investigate if BR had reduced peak PFJCF compared to forward running (FR) at the same speed, and (2) if PFJCF was reduced in BR, to investigate which biomechanical parameters explained this. It was hypothesized that (1) PFJCF would be lower in BR, and (2) that this would coincide with a reduced peak knee moment caused by altered ground reaction forces (GRFs). Twenty healthy subjects ran in forward and backward directions at consistent speed. Kinematic and ground reaction force data were collected; inverse dynamic and PFJCF analyses were performed. PFJCF were higher in FR than BR (4.5±1.5; 3.4±1.4BW; p<0.01). The majority of this difference (93.1%) was predicted by increased knee moments in FR compared to BR (157±54; 124±51 Nm; p<0.01). 54.8% of differences in knee moments could be predicted by the magnitude of the GRF (2.3±0.3; 2.4±0.2BW), knee flexion angle (44±6; 41±7) and center of pressure location on the foot (25±11; 12±6%) at time of peak knee moment. Results were not consistent in all subjects. It was concluded that BR had reduced PFJCF compared to FR. This was caused by an increased knee moment, due to differences in magnitude and location of the GRF vector relative to the knee. BR can therefore be used to exercise with decreased PFJCF. PMID:22503882

  18. Apportion Everything: A New Joint Force Organization and Employment Construct

    DTIC Science & Technology

    2007-11-02

    documents and concepts include An Evolving Joint Perspective: US Joint Warfare and Crisis Resolution In the 21st Century, Joint Operations Concepts...descriptive acronyms for the instruments of power include DIME-FIL or MIDLIFE which includes finance, intelligence, and substitutes legal for judicial. 16...Perspective: US Joint Warfare and Crisis Resolution In the 21st Century (Washington, DC: Joint Chiefs of Staff, Directorate of Management Printing

  19. A History of Shoulder Surgery

    PubMed Central

    Iqbal, S; Jacobs, U; Akhtar, A; Macfarlane, R.J; Waseem, M

    2013-01-01

    Shoulder surgery has emerged from being a marginalised sub-speciality to being an area of much research and advancement within the last seventy years. This has been despite the complexity of the joint, and success majorly rests on parallel development of biomedical technology. This article looks at the past and present of shoulder surgery and discusses future directions in the speciality. PMID:24082968

  20. Shoulder pain

    MedlinePlus

    Pain - shoulder ... changes around the rotator cuff can cause shoulder pain. You may have pain when lifting the arm above your head or ... The most common cause of shoulder pain occurs when rotator cuff tendons ... The tendons become inflamed or damaged. This condition ...

  1. Lower limb joint forces during walking on the level and slopes at different inclinations.

    PubMed

    Alexander, Nathalie; Schwameder, Hermann

    2016-03-01

    Sloped walking is associated with an increase of lower extremity joint loading compared to level walking. Therefore, the aim of this study was to analyse lower limb joint compression forces as well as tibiofemoral joint shear forces during sloped walking at different inclinations. Eighteen healthy male participants (age: 27.0 ± 4.7 years, height: 1.80 ± 0.05 m, mass: 74.5 ± 8.2 kg) were asked to walk at a pre-set speed of 1.1m/s on a ramp (6 m × 1.5 m) at the slopes of -18°, -12°, -6°, 0°, 6°, 12° and 18°. Kinematic data were captured with a twelve-camera motion capture system (Vicon). Kinetic data were recorded with two force plates (AMTI) imbedded into a ramp. A musculoskeletal model (AnyBody) was used to compute lower limb joint forces. Results showed that downhill walking led to significantly increased hip, tibiofemoral and patellofemoral joint compression forces (p<0.05) and to significantly decreased ankle joint compression forces (p<0.05). Uphill walking significantly increased all lower limb joint compression forces with increasing inclination (p<0.05). Findings that downhill walking is a stressful task for the anterior cruciate ligament could not be supported in the current study, since anterior tibiofemoral joint shear forces did not increase with the gradient. Due to diverse tibiofemoral joint shear force patterns in the literature, results should be treated with caution in general. Finally, lower limb joint force analyses provided more insight in the structure loading conditions during sloped walking than joint moment analyses.

  2. Kinematics of the Shoulder Girdle During Pointing: Coordination Between Joints and their Contribution to the Peri-Personal Workspace.

    PubMed

    Roby-Brami, Agnès; Robertson, Johanna V G; Roren, Alexandra; Lefèvre-Colau, Marie-Martine

    2016-08-19

    This study explored the coordination between the components of the shoulder girdle (clavicle, scapula and humerus), and how they contribute to hand movement in the peri-personal space. Shoulder girdle motion was recorded in 10 healthy subjects during pointing movements to 9 targets in the peri-personal space, using electromagnetic sensors fixed to the trunk, scapula and upper arm. Most of the 9 degrees of freedom (DoF) of the shoulder girdle were finely scaled to target position. Principle component analysis revealed that the 6 DoF of scapula-thoracic motion were coordinated in three elementary patterns (protraction, shrug and lateral rotation). The ratio of gleno-humeral to scapulo-thoracic global motion was close to 2:1. A direct kinematic procedure showed that if no scapular motion occurred, the workspace would be reduced by 15.8 cm laterally, 13.7 cm vertically and 4.8 cm anteriorly. Scapulo-thoracic motion should be taken into account when investigating the physiology of upper-limb movements.

  3. [Winter sports and shoulder arthroplasty].

    PubMed

    Kirchhoff, C; Imhoff, A B; Hinterwimmer, S

    2008-09-01

    Nowadays, a general negative evaluation of sportive activity regarding different kinds of sport following arthroplasty is at present no more scientifically supported. However, at present no valid guidelines regarding sportive activity of patients after implantation of shoulder joint arthroplasty exist. The question regarding the ability of performing winter sports activities of patients treated with shoulder joint endoprothesis has not been answered so far. Therefore the aim of the presented work was to identify winter sports-specific risks for patients treated with shoulder joint endoprothesis as well as to critically discuss the actual literature in refer to winter sport activities. Criteria for the education of patients with shoulder joint endoprothesis as well as consultation regarding winter sport activities will be provided for the orthopaedic surgeon.

  4. Heads, Shoulders, Elbows, Knees, and Toes: Modular Gdf5 Enhancers Control Different Joints in the Vertebrate Skeleton

    PubMed Central

    Schoor, Michael; Mortlock, Doug P.; Reddi, A. Hari; Kingsley, David M.

    2016-01-01

    Synovial joints are crucial for support and locomotion in vertebrates, and are the frequent site of serious skeletal defects and degenerative diseases in humans. Growth and differentiation factor 5 (Gdf5) is one of the earliest markers of joint formation, is required for normal joint development in both mice and humans, and has been genetically linked to risk of common osteoarthritis in Eurasian populations. Here, we systematically survey the mouse Gdf5 gene for regulatory elements controlling expression in synovial joints. We identify separate regions of the locus that control expression in axial tissues, in proximal versus distal joints in the limbs, and in remarkably specific sub-sets of composite joints like the elbow. Predicted transcription factor binding sites within Gdf5 regulatory enhancers are required for expression in particular joints. The multiple enhancers that control Gdf5 expression in different joints are distributed over a hundred kilobases of DNA, including regions both upstream and downstream of Gdf5 coding exons. Functional rescue tests in mice confirm that the large flanking regions are required to restore normal joint formation and patterning. Orthologs of these enhancers are located throughout the large genomic region previously associated with common osteoarthritis risk in humans. The large array of modular enhancers for Gdf5 provide a new foundation for studying the spatial specificity of joint patterning in vertebrates, as well as new candidates for regulatory regions that may also influence osteoarthritis risk in human populations. PMID:27902701

  5. Intra-Articular Knee Contact Force Estimation During Walking Using Force-Reaction Elements and Subject-Specific Joint Model.

    PubMed

    Jung, Yihwan; Phan, Cong-Bo; Koo, Seungbum

    2016-02-01

    Joint contact forces measured with instrumented knee implants have not only revealed general patterns of joint loading but also showed individual variations that could be due to differences in anatomy and joint kinematics. Musculoskeletal human models for dynamic simulation have been utilized to understand body kinetics including joint moments, muscle tension, and knee contact forces. The objectives of this study were to develop a knee contact model which can predict knee contact forces using an inverse dynamics-based optimization solver and to investigate the effect of joint constraints on knee contact force prediction. A knee contact model was developed to include 32 reaction force elements on the surface of a tibial insert of a total knee replacement (TKR), which was embedded in a full-body musculoskeletal model. Various external measurements including motion data and external force data during walking trials of a subject with an instrumented knee implant were provided from the Sixth Grand Challenge Competition to Predict in vivo Knee Loads. Knee contact forces in the medial and lateral portions of the instrumented knee implant were also provided for the same walking trials. A knee contact model with a hinge joint and normal alignment could predict knee contact forces with root mean square errors (RMSEs) of 165 N and 288 N for the medial and lateral portions of the knee, respectively, and coefficients of determination (R2) of 0.70 and -0.63. When the degrees-of-freedom (DOF) of the knee and locations of leg markers were adjusted to account for the valgus lower-limb alignment of the subject, RMSE values improved to 144 N and 179 N, and R2 values improved to 0.77 and 0.37, respectively. The proposed knee contact model with subject-specific joint model could predict in vivo knee contact forces with reasonable accuracy. This model may contribute to the development and improvement of knee arthroplasty.

  6. Evaluation of knee joint forces during kneeling work with different kneepads.

    PubMed

    Xu, Hang; Jampala, Sree; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew

    2017-01-01

    The main purpose of this study is to determine knee joint forces resulting from kneeling work with and without kneepads to quantify how different kneepads redistribute force. Eleven healthy males simulated a tile setting task to different locations during six kneepad states (five different kneepad types and without kneepad). Peak and average forces on the anatomical landmarks of both knees were obtained by custom force sensors. The results revealed that kneepad design can significantly modify the forces on the knee joint through redistribution. The Professional Gel design was preferred among the five tested kneepads which was confirmed with both force measurements and participants' responses. The extreme reaching locations induced significantly higher joint forces on left knee or right knee depending on task. The conclusion of this study is that a properly selected kneepad for specific tasks and a more neutral working posture can modify the force distribution on the knees and likely decrease the risk of knee disorders from kneeling work.

  7. Contributions of individual muscles to hip joint contact force in normal walking.

    PubMed

    Correa, Tomas A; Crossley, Kay M; Kim, Hyung J; Pandy, Marcus G

    2010-05-28

    The human hip joint withstands high contact forces during daily activity and is therefore susceptible to injury and structural deterioration over time. Knowledge of muscle-force contributions to hip joint loading may assist in the development of strategies to prevent and manage conditions such as osteoarthritis, femoro-acetabular impingement and fracture. The main aim of this study was to determine the contributions of individual muscles to hip contact force in normal walking. Muscle contributions to hip contact force were calculated based on a previously published dynamic optimization solution for normal walking, which provided the time histories of joint motion, ground reaction forces, and muscle forces during the stance and swing phases of gait. The force developed by each muscle plus its contribution to the ground reaction force were used to determine the muscle's contribution to hip contact force. Muscles were the major contributors to hip contact force, with gravitational and centrifugal forces combined contributing less than 5% of the total contact force. Four muscles that span the hip - gluteus medius, gluteus maximus, iliopsoas, and hamstrings - contributed most significantly to the three components of the hip contact force and hip contact impulse (integral of hip contact force over time). Three muscles that do not span the hip - vasti, soleus, and gastrocnemius - also contributed substantially to hip joint loading. These results provide additional insight into lower-limb muscle function during walking and may also be relevant to studies of cartilage degeneration and bone remodelling at the hip.

  8. Recent advances in shoulder research.

    PubMed

    Killian, Megan L; Cavinatto, Leonardo; Galatz, Leesa M; Thomopoulos, Stavros

    2012-06-15

    Shoulder pathology is a growing concern for the aging population, athletes, and laborers. Shoulder osteoarthritis and rotator cuff disease represent the two most common disorders of the shoulder leading to pain, disability, and degeneration. While research in cartilage regeneration has not yet been translated clinically, the field of shoulder arthroplasty has advanced to the point that joint replacement is an excellent and viable option for a number of pathologic conditions in the shoulder. Rotator cuff disease has been a significant focus of research activity in recent years, as clinicians face the challenge of poor tendon healing and irreversible changes associated with rotator cuff arthropathy. Future treatment modalities involving biologics and tissue engineering hold further promise to improve outcomes for patients suffering from shoulder pathologies.

  9. Evidence of rapid Cenozoic uplift of the shoulder escarpment of the Cenozoic West Antarctic rift system and a speculation on possible climate forcing

    USGS Publications Warehouse

    Behrendt, John C.; Cooper, A.

    1991-01-01

    The Cenozoic West Antarctic rift system, characterized by Cenozoic bimodal alkalic volcanic rocks, extends over a largely ice-covered area, from the Ross Sea nearly to the Bellingshausen Sea. Various lines of evidence lead to the following interpretation: the transantarctic Mountains part of the rift shoulder (and probably the entire shoulder) has been rising since about 60 Ma, at episodic rates of ~1 km/m.y., most recently since mid-Pliocene Time, rather than continuously at the mean rate of 100 m/m.y. Uplift rates vary along the scarp, which is cut by transverse faults. It is speculated that this uplift may have climatically forced the advance of the Antarctic ice sheet since the most recent warm period. A possible synergistic relation is suggested between episodic tectonism, mountain uplift, and volcanism in the Cenozoic West Antarctic rift system and waxing and waning of the Antarctic ice sheet beginning about earliest Oligocene time. -from Authors

  10. Residual force enhancement during multi-joint leg extensions at joint- angle configurations close to natural human motion.

    PubMed

    Paternoster, Florian Kurt; Seiberl, Wolfgang; Hahn, Daniel; Schwirtz, Ansgar

    2016-03-21

    The isometric steady-state forces following lengthening are greater than those produced at the same muscle length and activation level but without prior lengthening. Although residual force enhancement (RFE) has been investigated across a range of conditions, its relevance for daily human movement is still poorly understood. We aimed to study RFE in a setup imitating daily activity, i.e., submaximal activation of the lower extremity's muscles with slightly flexed knee joints comparable to human walking. A motor-driven leg press dynamometer was used for randomly arranged purely isometric and isometric-eccentric-isometric contractions. Thirteen subjects performed multi-joint leg extensions, which were feedback-controlled at 30% of maximum voluntary vastus lateralis activation. Isometric-eccentric-isometric contractions incorporated a stretch from 30° to 50° knee flexion, while isometric contractions were performed at 50° knee flexion. Isometric contractions following stretch and purely isometric reference contractions were performed at 50° knee flexion. Kinematics, forces, and muscular activity were measured using 3D optical motion tracking, force plates, and surface EMG of 9 lower limb muscles of the right leg and joint torques were calculated by inverse dynamics. Variables of standardization (EMG, joint angles) showed no differences between contraction conditions. Eight of 13 subjects showed RFE of up to 24.8±32.5% for external forces and joint torques. Because the remaining 5 non-responders failed to produce enhanced forces during the stretch, we believe that RFE is functionally relevant for muscle function comparable to everyday human motion but only if there is enhanced force during stretch that sufficiently triggers mechanisms underlying RFE.

  11. The relationship between lower neck shear force and facet joint kinematics during automotive rear impacts.

    PubMed

    Stemper, Brian D; Yoganandan, Narayan; Pintar, Frank A; Maiman, Dennis J

    2011-04-01

    A primary goal of biomechanical safety research is the definition of localized injury thresholds in terms of quantities that are repeatable and easily measureable during experimentation. Recent biomechanical experimentation using human cadavers has highlighted the role of lower cervical facet joints in the injury mechanism resulting from low-speed automotive rear impacts. The present study was conducted to correlate lower neck forces and moments with facet joint motions during simulated rear impacts in an effort to define facet joint injury tolerance thresholds that can be used to assess automobile safety. Four male and four female intact head-neck complexes were obtained from cadaveric specimens and subjected to simulated automotive rear impacts using a pendulum-minisled device. Cervical spine segmental angulations and localized facet joint kinematics were correlated to shear and axial forces, and bending moments at the cervico-thoracic junction using linear regression. R(2) coefficients indicated that spinal kinematics correlated well with lower neck shear force and bending moment. Correlation slope was steeper in female specimens, indicating greater facet joint motions for a given loading magnitude. This study demonstrated that lower neck loads can be used to predict lower cervical facet joint kinematics during automotive rear impacts. Higher correlation slope in female specimens corresponds to higher injury susceptibility in that population. Although lower neck shear force and bending moment demonstrated adequate correlation with lower cervical facet joint motions, shear force is likely the better predictor due to similarity in the timing of peak magnitudes with regard to maximum facet joint motions.

  12. Evidence of rapid Cenozoic uplift of the shoulder escarpment of the Cenozoic West Antarctic rift system and a speculation on possible climate forcing

    SciTech Connect

    Behrendt, J.C. ); Cooper, A. )

    1991-04-01

    The Cenzoic West Antarctic rift system, characterized by Cenozoic bimodal alkalic volcanic rocks, extends over a largely ice-covered area, from the Ross Sea nearly to the Bellingshausen Sea. It is bounded on one side by a spectacular 4-to 5-km-high rift-shoulder scarp (maximum bedrock relief 5 to 7 km) from northern Victoria Land-Queen Maud Mountains to the Ellsworth-Whitmore-Horlick Mountains. Jurassic tholeiites crop out with the late Cenozoic volcanic rocks along the section of the Transantarctic Mountains from northern Victoria Land to the Horlick Mountains. The Cenozoic rift shoulder diverges here from the Jurassic tholeiite trend, and the tholeiites are exposed discontinuously along the lower elevation (1-2 km) section of the Transantarctic Mountains to the Weddell Sea. Various lines of evidence, no one of which is independently conclusive, lead the authors (as others have also suggested) to interpret the following. The Transantarctic Mountains part of the rift shoulder (and probably the entire shoulder) has been rising since about 60 Ma, at episodic rates of {approximately}1 km/m.y., most recently since mid-Pliocene time, rather than continuously at the mean rate of 100m/m.y. Uplift rates vary along the scarp, which is cut by transverse faults. The authors speculate that this uplift may have climatically forced the advance of the Antarctic ice sheet since the most recent warm period. They suggest a possible synergistic relation between episodic tectonism, mountain uplift, and volcanism in the Cenozoic West Antarctic rift system and waxing and waning of the Antarctic ice sheet beginning about earliest Oligocene time.

  13. Shoulder Arthroscopy

    MedlinePlus

    ... affect how your shoulder heals, lying flat may pull on your shoulder and cause discomfort. Some patients are more comfortable sleeping in a reclining chair or propped up in bed during the first days a er ...

  14. Frozen shoulder.

    PubMed Central

    Anton, H. A.

    1993-01-01

    The frozen shoulder is a common cause of shoulder pain and disability. Most patients slowly improve over 12 to 24 months. Some have prolonged loss of movement, pain, and associated disability. Treatments include physiotherapy, corticosteroid injections, and manipulation. Clinical trials of these treatments have produced conflicting results. PMID:8374364

  15. Joint force protection advanced security system (JFPASS) "the future of force protection: integrate and automate"

    NASA Astrophysics Data System (ADS)

    Lama, Carlos E.; Fagan, Joe E.

    2009-09-01

    The United States Department of Defense (DoD) defines 'force protection' as "preventive measures taken to mitigate hostile actions against DoD personnel (to include family members), resources, facilities, and critical information." Advanced technologies enable significant improvements in automating and distributing situation awareness, optimizing operator time, and improving sustainability, which enhance protection and lower costs. The JFPASS Joint Capability Technology Demonstration (JCTD) demonstrates a force protection environment that combines physical security and Chemical, Biological, Radiological, Nuclear, and Explosive (CBRNE) defense through the application of integrated command and control and data fusion. The JFPASS JCTD provides a layered approach to force protection by integrating traditional sensors used in physical security, such as video cameras, battlefield surveillance radars, unmanned and unattended ground sensors. The optimization of human participation and automation of processes is achieved by employment of unmanned ground vehicles, along with remotely operated lethal and less-than-lethal weapon systems. These capabilities are integrated via a tailorable, user-defined common operational picture display through a data fusion engine operating in the background. The combined systems automate the screening of alarms, manage the information displays, and provide assessment and response measures. The data fusion engine links disparate sensors and systems, and applies tailored logic to focus the assessment of events. It enables timely responses by providing the user with automated and semi-automated decision support tools. The JFPASS JCTD uses standard communication/data exchange protocols, which allow the system to incorporate future sensor technologies or communication networks, while maintaining the ability to communicate with legacy or existing systems.

  16. History of the Standing Joint Force Headquarters for Elimination (SJFHQ-E): No More Ad Hoc

    DTIC Science & Technology

    2014-05-22

    for a Standing Joint Force Headquarters (SJFHQ) - Core Element (CE). Washington, DC: Joint Chiefs of Staff, 2008. Creswell , John W. Qualitative...reduce the threat to the United States and its allies from nuclear, biological, chemical (NBC) weapons … as well as provide research and development...that were known and available for this research project. Project 31 Due to lack of official

  17. The Closure of U.S. Joint Forces Command - Mission Accomplished?

    DTIC Science & Technology

    2011-06-18

    importance of defending North Atlantic sea 1 Leo P. Hirrel with William R. McClintock ; United States...3 Hirrel with McClintock , xiii. 5 1999.4 To the casual observer very little change was apparent, but in the words of... McClintock , 53. 5 Ibid., 53. 6 U.S. Joint Forces Command, Command Overview Briefing, Norfolk, VA: Office of Public Affairs, U.S. Joint Forces Command

  18. Influence of clamp-up force on the strength of bolted composite joints

    NASA Astrophysics Data System (ADS)

    Horn, Walter J.; Schmitt, Ron R.

    1994-03-01

    Composite materials offer the potential for a reduction in the number of individual parts and joints in a structure because large one-piece components can replace multipart assemblies. Nevertheless, there are many situations where composite parts must be joined and often mechanical fasteners provide the only practical method of joining those parts. The long-term strength of mechanically fastened joints of composite members can be directly affected by the clamp-up force of the fastener and thus perhaps by the relaxation of this force due to the viscoelastic character of the composite materials of the joint. Methods for predicting the effect of bolt clamp-up force relaxation on the strength of mechanically fastened joints of thermoplastic composite materials were investigated during the present study. A test program, using two thermoplastic composite materials, was conducted to determine the influence of clamp-up force on joint strength, to measure the relaxation of the joint clamp-up force with time, and to measure the change of joint strength as a function of time.

  19. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces.

    PubMed

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F; Fregly, Benjamin J; Delp, Scott L; Banks, Scott A; Pandy, Marcus G; D'Lima, Darryl D; Lloyd, David G

    2013-11-15

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model.

  20. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces

    PubMed Central

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F.; Fregly, Benjamin J.; Delp, Scott L.; Banks, Scott A.; Pandy, Marcus G.; D’Lima, Darryl D.; Lloyd, David G.

    2013-01-01

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. PMID:24074941

  1. A leader-follower relationship in joint action on a discrete force production task.

    PubMed

    Masumoto, Junya; Inui, Nobuyuki

    2014-11-01

    The present study examined the development of a leader-follower relationship in joint action performed by participants with different skill levels. Two participants were instructed to produce discrete isometric forces such that the sum of the forces was the target force. The task did not prescribe the onset time or share of force each participant contributed to the target force. Although novices with low force variability did not produce an earlier force than those with high force variability in the novice-novice group, experienced participants produced an earlier force than novices in the novice-experienced group. While participants with low force variability always produced a stronger force than those with high force variability in both the groups, there was no significant difference in force distributions between participants with low and high force variabilities. Although a novice-experienced pair produced force more complementarily than a novice-novice pair in the first practice block, the difference between pairs vanished after the first practice block, suggesting that leader-follower relations were not always beneficial to task performance. In addition, practice of the joint action did not transfer to individual action.

  2. A finite element musculoskeletal model of the shoulder mechanism.

    PubMed

    van der Helm, F C

    1994-05-01

    The finite element method described in this study provides an easy method to simulate the kinetics of multibody mechanisms. It is used in order to develop a musculoskeletal model of the shoulder mechanism. Each relevant morphological structure has been represented by an appropriate element. For the shoulder mechanism two special-purpose elements have been developed: a SURFACE element representing the scapulothoracic gliding plane and a CURVED-TRUSS element to represent muscles which are wrapped around bony contours. The model contains four bones, three joints, three extracapsular ligaments, the scapulothoracic gliding plane and 20 muscles and muscle parts. In the model, input variables are the positions of the shoulder girdle and humerus and the external load on the humerus. Output variables are muscles forces subject to an optimization procedure in which the mechanical stability of the glenohumeral joint is one of the constraints. Four different optimization criteria are compared. For 12 muscles, surface EMG is used to verify the model. Since the optimum muscle length and force-length relationship are unknown, and since maximal EMG amplitude is length dependent, verification is only possible in a qualitative sense. Nevertheless, it is concluded that a detailed model of the shoulder mechanism has been developed which provides good insight into the function of morphological structures.

  3. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement

    PubMed Central

    Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A.; Cates, Harold E.

    2016-01-01

    Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05). No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups. PMID:27258086

  4. Shoulder Injuries in the Overhead Throwing Athlete.

    PubMed

    Mlynarek, Ryan A; Lee, Simon; Bedi, Asheesh

    2017-02-01

    The overhead pitching motion is a coordinated sequence of movements that subjects the shoulder to extreme forces. The ultimate goal of this complex, dynamic activity is to generate high ball velocity and accuracy. In doing so, repetitive throwing can cause adaptive and pathologic changes in the thrower's shoulder. This article reviews the relevant shoulder anatomy, the kinetic chain, and throwing mechanics, as well as common shoulder injuries and surgical options for the treating orthopedic surgeon.

  5. Joint Force Quarterly. Number 27, Winter 2000-01

    DTIC Science & Technology

    2001-04-01

    rapidly overcome enemy port denial operations. Second, it took months to es- tablish an offensive capability in-theater. We need more rapid force...before Serbia agreed to pull its forces from Kosovo. The reasons for this deci- sion were more self -evident than real- ized at the time. The withdrawal...That a corps head- quarters with more than 500 officers, noncommissioned officers, and sol- diers was necessary to coordinate a 5,000-man task force

  6. Joint line elevation in revision TKA leads to increased patellofemoral contact forces.

    PubMed

    König, Christian; Sharenkov, Alexey; Matziolis, Georg; Taylor, William R; Perka, Carsten; Duda, Georg N; Heller, Markus O

    2010-01-01

    One difficulty in revision total knee arthroplasty (TKA) is the management of distal femoral bone defects in which a joint line elevation (JLE) is likely to occur. Although JLE has been associated with inferior clinical results, the effect that an elevated joint line has on knee contact forces has not been investigated. To understand the clinical observations and elaborate the potential risk associated with a JLE, we performed a virtual TKA on the musculoskeletal models of four subjects. Tibio- and patellofemoral joint contact forces (JCF) were calculated for walking and stair climbing, varying the location of the joint line. An elevation of the joint line primarily affected the patellofemoral joint with JCF increases of as much as 60% of the patient's body weight (BW) at 10-mm JLE and 90% BW at 15-mm JLE, while the largest increase in tibiofemoral JCF was only 14% BW. This data demonstrates the importance of restoring the joint line, as it plays a critical role for the magnitudes of the JCFs, particularly for the patellofemoral joint. JLE caused by managing distal femoral defects with downsizing and proximalizing the femoral component could increase the patellofemoral contact forces, and may be a contributing factor to postoperative complications such as pain, polyethylene wear, and limited function.

  7. Joint Force Quarterly. Issue 69, 2nd Quarter 2013

    DTIC Science & Technology

    2013-04-01

    force and justice.”21 About half a century later, French philosopher and mathematician Blaise Pascal mused that “justice without force is...and Lawes of Armes,” in The Strategy Makers, 69, 80. 22 Blaise Pascal , Pensées sur la Réligion et d’autres sujets, published posthumously (Paris: G

  8. Enhanced Army Airborne Forces: A New Joint Operational Capability

    DTIC Science & Technology

    2014-01-01

    The 1994 Rwandan genocide involved atrocities committed through- out the country, in a remote and underdeveloped region of sub- Saharan Africa far...Armored Infantry Forces . . . . . . . . . . . . 57 Vignette 1: Counter Genocide ...establishing an enclave (e.g., to prevent genocide ) • rapidly interposing a peacekeeping force in a time-sensitive situ- ation. 4 Enhanced Army Airborne

  9. Biomechanics of reverse total shoulder arthroplasty.

    PubMed

    Berliner, Jonathan L; Regalado-Magdos, Ashton; Ma, C Benjamin; Feeley, Brian T

    2015-01-01

    Reverse total shoulder arthroplasty is an effective procedure for treatment of glenohumeral joint disease among patients with severe rotator cuff deficiency. Improvements in prosthetic design are the result of an evolved understanding of both shoulder and joint replacement biomechanics. Although modern generations of the reverse shoulder prosthesis vary in specific design details, they continue to adhere to Grammont's core principles demonstrated by his original Delta III prosthesis. This review article discusses the biomechanics of reverse total shoulder arthroplasty with a focus on elements of implant design and surgical technique that may affect stability, postoperative complications, and functional outcomes.

  10. SHOULDER DISORDERS AND OCCUPATION

    PubMed Central

    Linaker, CH; Walker-Bone, K

    2016-01-01

    Shoulder pain is very common and causes substantial morbidity. Standardised classification systems based upon presumed patho-anatomical origins have proved poorly reproducible and hampered epidemiological research. Despite this, there is evidence that exposure to combinations of physical workplace strains such as overhead working, heavy lifting and forceful work as well as working in an awkward posture increase the risk of shoulder disorders. Psychosocial risk factors are also associated. There is currently little evidence to suggest that either primary prevention or treatment strategies in the workplace are very effective and more research is required, particularly around the cost-effectiveness of different strategies. PMID:26612238

  11. American Indian Policy Review Commission Special Joint Task Force Report on Alaskan Native Issues.

    ERIC Educational Resources Information Center

    Congress of the U.S. Washington, DC. American Indian Policy Review Commission.

    Impact of the Alaskan Native Claims Settlement Act (ANCSA) on Alaskan Natives, particularly at village levels, is the focus of a joint task force report on Alaskan Native issues. Prepared for the American Indian Policy Review Commission, the report is the work of representatives from task forces on tribal government, federal, state, and tribal…

  12. Analysis of Marine Corps Efforts in the Pursuit of the Joint Blue Force Situational Awareness Capability

    DTIC Science & Technology

    2013-03-01

    Joint Blue Force Situational Awareness (JBFSA) capability. The shared battlespace is saturated with stovepipe digital situational awareness and...shared battlespace is saturated with stovepipe digital situational awareness and command and control systems. To ensure interoperability between ground...Combat Team BFT Blue Force Tracker BMC Brigade Modernization Command C2 Command and Control C2PC Command and Control Personal Computer

  13. Three-dimensional knee joint contact forces during walking in unilateral transtibial amputees.

    PubMed

    Silverman, Anne K; Neptune, Richard R

    2014-08-22

    Individuals with unilateral transtibial amputations have greater prevalence of osteoarthritis in the intact knee joint relative to the residual leg and non-amputees, but the cause of this greater prevalence is unclear. The purpose of this study was to compare knee joint contact forces and the muscles contributing to these forces between amputees and non-amputees during walking using forward dynamics simulations. We predicted that the intact knee contact forces would be higher than those of the residual leg and non-amputees. In the axial and mediolateral directions, the intact and non-amputee legs had greater peak tibio-femoral contact forces and impulses relative to the residual leg. The peak axial contact force was greater in the intact leg relative to the non-amputee leg, but the stance phase impulse was greater in the non-amputee leg. The vasti and hamstrings muscles in early stance and gastrocnemius in late stance were the largest contributors to the joint contact forces in the non-amputee and intact legs. Through dynamic coupling, the soleus and gluteus medius also had large contributions, even though they do not span the knee joint. In the residual leg, the prosthesis had large contributions to the joint forces, similar to the soleus in the intact and non-amputee legs. These results identify the muscles that contribute to knee joint contact forces during transtibial amputee walking and suggest that the peak knee contact forces may be more important than the knee contact impulses in explaining the high prevalence of intact leg osteoarthritis.

  14. Joint Force Quarterly. Issue 56, 1st Quarter, January 2010

    DTIC Science & Technology

    2010-01-01

    Memorandum (POM) for Fiscal Years 2012– 2017 ; and the Quadrennial Defense Review (QDR) personnel policy review and analysis are addressing the...Declassified_NIE_Key_Judgments.pdf>. 5 Jeffrey Buchanan, Maxie Y. Davis, and Lee T. Wight, “Death of the Combatant Command? Toward a Joint Interagency Approach

  15. Joint Force Quarterly. Issue 38, 3rd Quarter, July 2005

    DTIC Science & Technology

    2005-07-01

    anthropologists such as Gregory Bateson served the war effort directly, first conduct- ing intelligence opera- tions in Burma for the Office of...leaders such as General James L. Jones, Jr., USMC, Supreme Allied Commander, Europe, and Admi- ral Gregory G. Johnson, USN, combatant com- mander, Joint

  16. Shoulder MRI

    MedlinePlus

    ... of the shoulder uses a powerful magnetic field, radio waves and a computer to produce detailed pictures of ... scans, MRI does not utilize ionizing radiation. Instead, radio waves redirect alignment of hydrogen atoms that naturally exist ...

  17. Vaccination-related shoulder dysfunction.

    PubMed

    Bodor, Marko; Montalvo, Enoch

    2007-01-08

    We present two cases of shoulder pain and weakness following influenza and pneumococcal vaccine injections provided high into the deltoid muscle. Based on ultrasound measurements, we hypothesize that vaccine injected into the subdeltoid bursa caused a periarticular inflammatory response, subacromial bursitis, bicipital tendonitis and adhesive capsulitis. Resolution of symptoms followed corticosteroid injections to the subacromial space, bicipital tendon sheath and glenohumeral joint, followed by physical therapy. We conclude that the upper third of the deltoid muscle should not be used for vaccine injections, and the diagnosis of vaccination-related shoulder dysfunction should be considered in patients presenting with shoulder pain following a vaccination.

  18. Editorial Commentary: Shoulder Arthroscopy, Shoulder Hemiarthroplasty, and Total Shoulder Arthroplasty for Glenohumeral Osteoarthritis.

    PubMed

    Lubowitz, James H

    2015-06-01

    Shoulder arthroscopy offers a safe, effective, and less invasive alternative to arthroplasty in patients under 60 years of age with glenohumeral arthritis. However, indications include joint space of greater than 2 mm. For patients who do not meet arthroscopic indications, total shoulder arthroplasty is more effective than hemiarthroplasty. Performance and publication bias may effect generalizability of these findings. Biologic treatment options seem on the horizon.

  19. Joint Force Quarterly. Issue 70, 3rd Quarter, July 2013

    DTIC Science & Technology

    2013-07-01

    and future. Our compensation system strives to reflect the unique sacrifices our families make—the birthdays missed, friends left behind, and loved...working together to set up a system where pay remains competitive, health care becomes sustainable, and retire- ment stays solvent. Bonds of trust Our...Control System aircraft crew force based nearby at Tinker Air Force Base, my family and I have lasting memories of the power of tornadoes and their

  20. The Business of Bundling: Joining Forces on Joint Replacement.

    PubMed

    Kaldy, Joanne

    2016-03-01

    A mandated bundled-payment program for joint replacement is in place in several regions across the country, and practitioners such as pharmacists are still sorting out their roles in this federal initiative. To get involved, pharmacists need to establish connections with area hospitals and physician groups to promote and document their ability to manage medications, reduce and eliminate medication-related problems and rehospitalizations, and work with patients to maximize adherence and improve communication for those undergoing hip and knee replacement.

  1. Joint Task Force Command, Control, and Communications: Have We Improved

    DTIC Science & Technology

    1989-05-05

    DECLASSIFICATION / DOWNGRADING SC-iEDULE unlimited 4. PERFORMING ORGANIZATION REPORT NUMBER(S) 5 MONiTORING ORGANIZATION REPORT NUMBER(S) 6a. NAME OF...REPORT (Year, Month, Day). 11 PAGE COUNT Monograph IFROM _____TO ____ 89/ 5 / 5 55 16. SUPPLEMENTARY NOTATION 17. COSATI CODES , 18. SUBJECT TERMS (Continue...cited, the same joint C3 problems kept reappearing; 5 )the reappearing problems were not fixed because of the services refusal to accept substantial

  2. Is Lifelong Knee Joint Force from Work, Home, and Sport Related to Knee Osteoarthritis?

    PubMed Central

    Ratzlaff, Charles R.; Koehoorn, Mieke; Cibere, Jolanda; Kopec, Jacek A.

    2012-01-01

    Purpose. To investigate the association of cumulative lifetime knee joint force on the risk of self-reported medically-diagnosed knee osteoarthritis (OA). Methods. Exposure data on lifetime physical activity type (occupational, household, sport/recreation) and dose (frequency, intensity, duration) were collected from 4,269 Canadian men and women as part of the Physical Activity and Joint Heath cohort study. Subjects were ranked in terms of the “cumulative peak force index”, a measure of lifetime mechanical knee force. Multivariable logistic regression was conducted to obtain adjusted effects for mean lifetime knee force on the risk of knee OA. Results. High levels of total lifetime, occupational and household-related force were associated with an increased in risk of OA, with odds ratio's ranging from approximately 1.3 to 2. Joint injury, high BMI and older age were related to risk of knee OA, consistent with previous studies. Conclusions. A newly developed measure of lifetime mechanical knee force from physical activity was employed to estimate the risk of self-reported, medically-diagnosed knee OA. While there are limitations, this paper suggests that high levels of total lifetime force (all domains combined), and occupational force in men and household force in women were risk factors for knee OA. PMID:22848225

  3. Is there an association between the individual anatomy of the scapula and the development of rotator cuff tears or osteoarthritis of the glenohumeral joint?: A radiological study of the critical shoulder angle.

    PubMed

    Moor, B K; Bouaicha, S; Rothenfluh, D A; Sukthankar, A; Gerber, C

    2013-07-01

    We hypothesised that a large acromial cover with an upwardly tilted glenoid fossa would be associated with degenerative rotator cuff tears (RCTs), and conversely, that a short acromion with an inferiorly inclined glenoid would be associated with glenohumeral osteoarthritis (OA). This hypothesis was tested using a new radiological parameter, the critical shoulder angle (CSA), which combines the measurements of inclination of the glenoid and the lateral extension of the acromion (the acromion index). The CSA was measured on standardised radiographs of three groups: 1) a control group of 94 asymptomatic shoulders with normal rotator cuffs and no OA; 2) a group of 102 shoulders with MRI-documented full-thickness RCTs without OA; and 3) a group of 102 shoulders with primary OA and no RCTs noted during total shoulder replacement. The mean CSA was 33.1° (26.8° to 38.6°) in the control group, 38.0° (29.5° to 43.5°) in the RCT group and 28.1° (18.6° to 35.8°) in the OA group. Of patients with a CSA > 35°, 84% were in the RCT group and of those with a CSA < 30°, 93% were in the OA group. We therefore concluded that primary glenohumeral OA is associated with significantly smaller degenerative RCTs with significantly larger CSAs than asymptomatic shoulders without these pathologies. These findings suggest that individual quantitative anatomy may imply biomechanics that are likely to induce specific types of degenerative joint disorders.

  4. Articular nodular fasciitis of the right shoulder joint: report of an unusual case with focus on immunohistochemical differential diagnosis.

    PubMed

    Tajima, Shogo; Zuki, Tomoyukisu; Koda, Kenji

    2015-01-01

    The mesenchymal lesion nodular fasciitis (NF) can affect various sites of the body but usually arises in subcutaneous tissue or occasionally skeletal muscle. NF is not commonly known to arise in joints, and articular NF is extremely rare. Herein, we present a case of a 54-year-old woman with articular NF. No sign of recurrence was observed after surgical piecemeal removal with a suspected positive surgical margin. In our case, a differential diagnosis of NF, desmoid-type fibromatosis, and low-grade myofibroblastic sarcoma was considered. Stromal hyalinization, a characteristic of articular NF, made the diagnosis somewhat difficult, although typical NF morphology was present. Immunohistochemical analysis of α-smooth muscle actin, desmin, β-catenin, and protein gene product 9.5 expression along with close morphological examination provided a reliable distinction.

  5. Joint Force Quarterly. Issue 67, 4th Quarter, October 2012

    DTIC Science & Technology

    2012-10-01

    C e n t e r f o r t e C h n o lo g y a n d n a t io n a l S e C u r...Going Farther by Going Together Building Partner Capacity in Africa By C h a r l E s W . h o o p E r If you want to go quickly, go alone. If you want...n o v i C h SecuriTy Force ASSiSTAnce in a Time of Austerity U.S. Navy (Troy Latham) special operations Marines observe Armed Forces

  6. In vivo pediatric shoulder muscle volumes and their relationship to 3D strength.

    PubMed

    Im, Hyun Soo; Alter, Katharine E; Brochard, Sylvain; Pons, Christelle; Sheehan, Frances T

    2014-08-22

    In the pediatric shoulder, injury and pathology can disrupt the muscle force balance, resulting in severe functional losses. As little data exists pertaining to in vivo pediatric shoulder muscle function, musculoskeletal data are crucially needed to advance the treatment of pediatric shoulder pathology/injury. Therefore, the purpose of this study was to develop a pediatric database of in vivo volumes for the major shoulder muscles and correlate these volumes with maximum isometric flexion/extension, internal/external rotation, and abduction/adduction joint moments. A methodology was developed to derive 3D shoulder muscle volumes and to divide the deltoid into sub-units with unique torque producing capabilities, based on segmentation of three-dimensional magnetic resonance images. Eleven typically developing children/adolescents (4F/7M, 12.0 ± 3.2 years, 150.8 ± 16.7 cm, 49.2 ± 16.4 kg) participated. Correlation and regression analyses were used to evaluate the relationship between volume and maximum, voluntary, isometric joint torques. The deltoid demonstrated the largest (30.4 ± 1.2%) and the supraspinatus the smallest (4.8 ± 0.5%) percent of the total summed volume of all six muscles evaluated. The anterior and posterior deltoid sections were 43.4 ± 3.9% and 56.6 ± 3.9% of the total deltoid volume. The percent volumes were highly consistent across subjects. Individual muscle volumes demonstrated moderate-high correlations with torque values (0.70-0.94, p<0.001). This study presents a comprehensive database documenting normative pediatric shoulder muscle volume. Using these data a clear relationship between shoulder volume and the torques they produce was established in all three rotational degrees-of-freedom. This study furthers the understanding of shoulder muscle function and serves as a foundation for evaluating shoulder injury/pathology in the pediatric/adolescent population.

  7. Comparison of joint space versus task force load distribution optimization for a multiarm manipulator system

    NASA Technical Reports Server (NTRS)

    Soloway, Donald I.; Alberts, Thomas E.

    1989-01-01

    It is often proposed that the redundancy in choosing a force distribution for multiple arms grasping a single object should be handled by minimizing a quadratic performance index. The performance index may be formulated in terms of joint torques or in terms of the Cartesian space force/torque applied to the body by the grippers. The former seeks to minimize power consumption while the latter minimizes body stresses. Because the cost functions are related to each other by a joint angle dependent transformation on the weight matrix, it might be argued that either method tends to reduce power consumption, but clearly the joint space minimization is optimal. A comparison of these two options is presented with consideration given to computational cost and power consumption. Simulation results using a two arm robot system are presented to show the savings realized by employing the joint space optimization. These savings are offset by additional complexity, computation time and in some cases processor power consumption.

  8. Measurement of intraarticular wrist joint biomechanics with a force controlled system.

    PubMed

    Erhart, Stefanie; Lutz, Martin; Arora, Rohit; Schmoelz, Werner

    2012-09-01

    Pathologies of the wrist, such as fractures or instabilities, can lead to alterations in joint biomechanics. Accurate treatment of these pathologies is a frequent challenge for the surgeon. For biomechanical investigations, a test-setup that applies physiological loading of the wrist joint is necessary. A force controlled test-bench with agonistic and antagonistic muscle forces was built to move six fresh frozen human upper extremities through flexion and extension of the wrist joint. Tendon forces, range of motion, intraarticular contact area and contact pressure of the lunate and scaphoid facet as well as tendon excursion were investigated and compared with the current literature. During wrist motion the extensors exerted double the force of the flexors. Capsulotomy and sensor insertion decreased the range of motion from 63.4° (SD 14.1) to 45.9° (SD 23.7). The ratio of force transmitted through the radius and ulna was 77:23 and pressure distribution between the scaphoid and lunate facet showed a 70:30 relationship. The obtained data indicate a good agreement with the available literature. Therefore, the force controlled test-bench in combination with intraarticular radiocarpal measurements can be used to investigate the influence of wrist pathologies on joint biomechanics.

  9. Joint Force Quarterly. Issue 44, 1st Quarter 2007

    DTIC Science & Technology

    2007-01-01

    Burnside; and all the diverse forces operating in Virginia, Tennessee , northern Georgia, the deep South, and far West.25 This unity of command allowed...Rajneesh cult’s use of salmonella to sicken more than 700 people in Oregon in 1984. Responding to the attack in Japan (and without any

  10. Trunk muscle activation and associated lumbar spine joint shear forces under different levels of external forward force applied to the trunk.

    PubMed

    Kingma, Idsart; Staudenmann, Didier; van Dieën, Jaap H

    2007-02-01

    High anterior intervertebral shear loads could cause low back injuries and therefore the neuromuscular system may actively counteract these forces. This study investigated whether, under constant moment loading relative to L3L4, an increased externally applied forward force on the trunk results in a shift in muscle activation towards the use of muscles with more backward directed lines of action, thereby reducing the increase in total joint shear force. Twelve participants isometrically resisted forward forces, applied at several locations on the trunk, while moments were held constant relative to L3L4. Surface EMG and lumbar curvature were measured, and an EMG-driven muscle model was used to calculate compression and shear forces at all lumbar intervertebral joints. Larger externally applied forward forces resulted in a flattening of the lumbar lordosis and a slightly more backward directed muscle force. Furthermore, the overall muscle activation increased. At the T12L1 to L3L4 joint, resulting joint shear forces remained small (less than 200N) because the average muscle force pulled backward relative to those joints. However, at the L5S1 joint the average muscle force pulled the trunk forward so that the increase in muscle force with increasing externally applied forward force caused a further rise in shear force (by 102.1N, SD=104.0N), resulting in a joint shear force of 1080.1N (SD=150.4N) at 50Nm moment loading. It is concluded that the response of the neuromuscular system to shear force challenges tends to increase rather than reduce the shear loading at the lumbar joint that is subjected to the highest shear forces.

  11. What Are Shoulder Problems?

    MedlinePlus

    ... nerves around the shoulder, surgery may be needed. Separation A shoulder separation occurs when the ligaments between the collarbone and ... on an outstretched hand. Treatment for a shoulder separation includes: Rest A sling to keep the shoulder ...

  12. The effects of therapeutic exercise using PNF on the size of calcium deposits, pain self-awareness, and shoulder joint function in a calcific tendinitis patient: a case study

    PubMed Central

    Oh, Dong-Gun; Yoo, Kyung-Tae

    2017-01-01

    [Purpose] The purpose of this case study was to identify the effects of independent and intensive therapeutic exercise using Proprioceptive neuromuscular facilitation on the size of calcium deposits, pain self-awareness, and shoulder joint function in a patient with calcific tendonitis. [Subject and Methods] The subject was a 42-year-old female patient with calcific tendonitis and acute pain who had difficulty with active movement and problems with general function. The independent and intensive Proprioceptive neuromuscular facilitation exercise was applied for 40 min twice a day five times a week for two weeks for a total of 20 times. An X-ray, the visual analog scale, a simple shoulder test, the Constant-Murley Scale, and passive range of motion was used to evaluate the patient’s change. [Results] The size of the calcium deposit, the visual analog scale score, and the simple shoulder test score decreased. The Constant-Murley Scale score and the passive range of motion were increased. [Conclusion] The results of this study suggested that intensive and independent therapeutic short-term exercise without any other exercise reduced pain and produced positive effects in shoulder function in a patient with the calcific tendonitis, which could confirm the importance of therapeutic exercise in the treatment of calcific tendonitis. PMID:28210065

  13. Exercise Design for the Joint Force 2020 Brigade Combat Team

    DTIC Science & Technology

    2012-03-22

    while inter-dispersed amongst complicated indigenous populations with different cultures, political, religious norms and motivations; the ―fog and...particularly in complex terrain and in military operations among the people .‖84 Even if ground forces are not used as our primary military instruments in...the people of the world.‖108 27 Unlike preceding constructs, this version places equal emphasis on having units prepare for each type of

  14. Joint Force Quarterly. Issue 42, 3rd Quarter, July 2006

    DTIC Science & Technology

    2006-07-01

    Millett  17  A Prescription for Protecting the Southern Approach by John A. Cope 22   The State Partnership Program: Vision to Reality by Pablo Pagan  26...An Interview with Terry J. Pudas, Acting Director, Department of Defense Office of Force Transformation 36  Implementing the Transformation Vision ...tion in an interview with the office’s acting director, Terry Pudas, who offers insight into the current vision of transformation. In this feature

  15. General Roy S. Geiger, USMC: Marine Aviator, Joint Force Commander

    DTIC Science & Technology

    2007-06-01

    undersupplied, even with Japanese forces furiously working to retake the island.7 Despite the strategic importance of holding Henderson Field and the...to deliver a final “knockout blow” to the Marines, 90 Geiger and Vandegrift furiously prepared for the inevitable ground assault. It was during... happy about getting orders from a staff that had no combat experience, but it worked out fairly well. General Geiger and his staff came in November

  16. Non-Lethal Weapons: Considerations for the Joint Force Commander

    DTIC Science & Technology

    2007-05-10

    a derivative of the opiate fentanyl, used by Russian military forces against Chechen terrorists in Moscow in October 2002. Unable to control the...populations. Instigators can organize and agitate a mob to engage in threatening behavior, and may attempt to employ lethal means from within that... mob . Combatants may seek shelter in homes, businesses, religious buildings, or medical facilities. It is in these scenarios that NLWs hold so much

  17. Joint Force Quarterly (JFQ). Issue 50, 3rd Quarter, 2008

    DTIC Science & Technology

    2008-01-01

    Richard L. Russell 92 Integration of Coalition Forces into the USCENTCOM Mission By John F. Couture 98 Battling Misperceptions: Challenges to...Army/ Russell Lee Klika); Navy damage control seamen taking samples of simulated anthrax during chemical, biological, radiological drill aboard USS...Instincts and the Dangers of Nuclear Weapons in Iranian Hands Dr. Richard L. Russell is a Professor of National Security Affairs in the Near East

  18. What It Takes. Air Force Command of Joint Operations

    DTIC Science & Technology

    2009-01-01

    ters staff. For the headquarters to reach full functionality, it needs to be augmented with additional staff from both the host service and the other...Operations Command Central SOCPAC Special Operations Command Pacific SOF special operations forces TAC CP tactical command post TACON tactical control ...defines control as 1. Authority that may be less than full command exercised by a commander over part of the activities of subordinate or other

  19. Joint Force Quarterly. Issue 55, 4th Quarter 2009

    DTIC Science & Technology

    2009-01-01

    Studies, Center for Naval Analyses, American Enterprise Insti- tute, Rocky Mountain Institute, two Defense Science Board (DSB) Energy Task Force teams...south, China. Russia touches China along a mountainous 36-km border running between Kazakhstan and Mongolia, but the remote frontier has not been a...inclusive from Lisbon to the Ural Mountains , including southern Europe and parts of trans-Caucasus. Even without Ukrainian membership in NATO

  20. Personnel Security during Joint Operations with Foreign Military Forces

    DTIC Science & Technology

    2013-08-01

    century society into the twenty-first century encounters a number of obstacles. Illiteracy and innumeracy rates are high, and repressive social values are...Operations with Foreign Military Forces Feature quickly degraded into executions for social infractions like blasphemy. Repression soon followed, and the...is functionally illiterate, how do we expect to close this gap without a massive education program to support it? Miscommunication is the breeding

  1. Joint Force Quarterly. Issue 41, 2nd Quarter, April 2006

    DTIC Science & Technology

    2006-04-01

    article argues that an integrated civil-mili- tary combatant command is the model for the United States to deter and defeat adver - saries and engage...healthy and fit force (for example, vaccinations and dental readiness), prevention of casualties (such as medical intelligence reports and digitized...particular, is well suited to cause the adver - sary to react with fear. Initially, it is fear of an attack, whether a preemptive strike or a response to

  2. Joint Task Force -Guantanamo Bay, Cuba: Open or Close?

    DTIC Science & Technology

    2013-03-01

    combination cells for legal visits (not to house detainees). Camp Echo requires a guard force of approximately 40 personnel.24 Camp Iguana Camp new mission...in 2008 was to house detainees who have received court- ordered releases. Camp Iguana has the capacity to hold 22 detainees who live in a complete...open, minimum-security environment. The detainees at Camp Iguana have 24-hour access to a recreation area, sleeping berths, and a laundry facility

  3. Joint Force Quarterly. Issue 45, 2d Quarter 2007

    DTIC Science & Technology

    2007-01-01

    r o f e s s i o n A l M i l i t A r y A n d s e c u r i t y J o u r n A l J O I N T F O R C E Q U A R T E R ...of the Joint Chiefs of Staff by National Defense University A P r o f e s s i o n A l M i l i t A r y A n d s e c u r i t y J o u r n A l J O I...Conceptualization of Islam and Terrorism By J. Keith Akins A P r o f e s s i o n A l M i l i tA r

  4. Are Standing Joint Task Force Headquarters the First Step in Transforming Cold War Formations?

    DTIC Science & Technology

    2002-05-01

    leoorst. 129 Jetfetrson Oavn Suihw ty,lte 1204, ArlingtOn, V 222024302. and t0 the Otfice of Manaqemett and Buidget. PaierwoeK Reduci on PrOlec (0704...Progress." 18. 113 "JFC Forum - The Persian Gulf War. Ten Years After." (Joint Forces Quarterly. Winter 2000-01). 10. 114 James R . Helmly, "Future U.S... R . Stocker. Canadian Jointery, (Joint Forces Quarterly, Winter 95-96), 116. & James R . Heimly. "Future U.S. Military Strategy: The Need for a

  5. Supraspinatus tendon load during abduction is dependent on the size of the critical shoulder angle: A biomechanical analysis.

    PubMed

    Gerber, Christian; Snedeker, Jess G; Baumgartner, Daniel; Viehöfer, Arnd F

    2014-07-01

    Shoulders with supraspinatus (SSP) tears are associated with significantly larger critical shoulder angles (CSA) compared to disease-free shoulders. We hypothesized that larger CSAs increase the ratio of joint shear to joint compression forces (defined as "instability ratio"), requiring substantially increased compensatory supraspinatus loads. A shoulder simulator with simulated deltoid, supraspinatus, infraspinatus/teres minor, and subscapularis musculotendinous units was constructed. The model was configured to represent either a normal CSA of 33° or a CSA characteristic of shoulders with rotator cuff tears (38°), and the components of the joint forces were measured. The instability ratio increased for the 38° CSA compared with the control CSA (33°) for a range of motion between 6° to 61° of thoracohumeral abduction with the largest differences in instability observed between 33° and 37° of elevation. In this range, SSP force had to be increased by 13-33% (15-23 N) to stabilize the arm in space. Our results support the concept that a high CSA can induce SSP overload particularly at low degrees of active abduction.

  6. A feasibility study for experimentally determining dynamic force distribution in a lap joint.

    SciTech Connect

    Mayes, Randall Lee

    2013-11-01

    Developing constitutive models of the physics in mechanical joints is currently stymied by inability to measure forces and displacements within the joint. The current state of the art estimates whole joint stiffness and energy loss per cycle from external measured force input and one or two acceleration responses. To validate constitutive models beyond this state requires a measurement of the distributed forces and displacements at the joint interface. Unfortunately, introducing measurement devices at the interface completely disrupts the desired physics. A feasibility study is presented for a non-intrusive method of solving for the interface dynamic forces from an inverse problem using full field measured responses. The responses come from the viewable surface of a beam. The noise levels associated with digital image correlation and continuous scanning laser Doppler velocimetry are evaluated from typical beam experiments. Two inverse problems are simulated. One utilizes the extended Sum of Weighted Accelerations Technique (SWAT). The second is a new approach dubbed the method of truncated orthogonal forces. These methods are much more robust if the contact patch geometry is well identified. Various approaches to identifying the contact patch are investigated, including ion marker tracking, Prussian blue and ultrasonic measurements. A typical experiment is conceived for a beam which has a lap joint at one end with a single bolt connecting it to another identical beam. In a virtual test using the beam finite element analysis, it appears that the SWAT inverse method requires evaluation of too many coefficients to adequately identify the force distribution to be viable. However, the method of truncated orthogonal forces appears viable with current digital image correlation (and probably other) imaging techniques.

  7. A musculoskeletal shoulder model based on pseudo-inverse and null-space optimization.

    PubMed

    Terrier, Alexandre; Aeberhard, Martin; Michellod, Yvan; Mullhaupt, Philippe; Gillet, Denis; Farron, Alain; Pioletti, Dominique P

    2010-11-01

    The goal of the present work was assess the feasibility of using a pseudo-inverse and null-space optimization approach in the modeling of the shoulder biomechanics. The method was applied to a simplified musculoskeletal shoulder model. The mechanical system consisted in the arm, and the external forces were the arm weight, 6 scapulo-humeral muscles and the reaction at the glenohumeral joint, which was considered as a spherical joint. The muscle wrapping was considered around the humeral head assumed spherical. The dynamical equations were solved in a Lagrangian approach. The mathematical redundancy of the mechanical system was solved in two steps: a pseudo-inverse optimization to minimize the square of the muscle stress and a null-space optimization to restrict the muscle force to physiological limits. Several movements were simulated. The mathematical and numerical aspects of the constrained redundancy problem were efficiently solved by the proposed method. The prediction of muscle moment arms was consistent with cadaveric measurements and the joint reaction force was consistent with in vivo measurements. This preliminary work demonstrated that the developed algorithm has a great potential for more complex musculoskeletal modeling of the shoulder joint. In particular it could be further applied to a non-spherical joint model, allowing for the natural translation of the humeral head in the glenoid fossa.

  8. Modeling of Human Joint Structures.

    DTIC Science & Technology

    1982-09-01

    Radial Lateral " epicondyle Olecranon Radius Ulna Figure 3. Lateral aspect of the right elbow joint. -17- Annular Ligament This strong band encircles... elbow joint, knee joint, human joints, shoulder joint, ankle joint, joint models, hip joint, ligaments. 20. ABSTRACT (Continue on reverse side If...ligaments. -A rather extended discussion of the articulations and anatomical descriptions of the elbow , shoulder, hip, knee and ankle joints are

  9. A Biomechanical Model Correlating Shoulder Kinetics to Pain in Young Baseball Pitchers

    PubMed Central

    Keeley, David W.; Oliver, Gretchen D.; Dougherty, Christopher P.

    2012-01-01

    Previous work has postulated that shoulder pain may be associated with increases in both peak shoulder anterior force and peak shoulder proximal force. Unfortunately these relationships have yet to be quantified. Thus, the purpose of this study was to associate these kinetic values with reported shoulder pain in youth baseball pitchers. Nineteen healthy baseball pitchers participated in this study. Segment based reference systems and established calculations were utilized to identify peak shoulder anterior force and peak shoulder proximal force. A medical history questionnaire was utilized to identify shoulder pain. Following collection of these data, the strength of the relationships between both peak shoulder anterior force and peak shoulder proximal force and shoulder pain were analyzed. Although peak anterior force was not significantly correlated to shoulder pain, peak proximal force was. These results lead to the development of a single variable logistic regression model able to accurately predict 84.2% of all cases and 71.4% of shoulder pain cases. This model indicated that for every 1 N increase in peak proximal force, there was a corresponding 4.6% increase in the likelihood of shoulder pain. The magnitude of peak proximal force is both correlated to reported shoulder pain and capable of being used to accurately predict the likelihood of experiencing shoulder pain. It appears that those pitchers exhibiting high magnitudes of peak proximal force are significantly more likely to report experiencing shoulder pain than those who generate lower magnitudes of peak proximal force. PMID:23486209

  10. A biomechanical model correlating shoulder kinetics to pain in young baseball pitchers.

    PubMed

    Keeley, David W; Oliver, Gretchen D; Dougherty, Christopher P

    2012-10-01

    Previous work has postulated that shoulder pain may be associated with increases in both peak shoulder anterior force and peak shoulder proximal force. Unfortunately these relationships have yet to be quantified. Thus, the purpose of this study was to associate these kinetic values with reported shoulder pain in youth baseball pitchers. Nineteen healthy baseball pitchers participated in this study. Segment based reference systems and established calculations were utilized to identify peak shoulder anterior force and peak shoulder proximal force. A medical history questionnaire was utilized to identify shoulder pain. Following collection of these data, the strength of the relationships between both peak shoulder anterior force and peak shoulder proximal force and shoulder pain were analyzed. Although peak anterior force was not significantly correlated to shoulder pain, peak proximal force was. These results lead to the development of a single variable logistic regression model able to accurately predict 84.2% of all cases and 71.4% of shoulder pain cases. This model indicated that for every 1 N increase in peak proximal force, there was a corresponding 4.6% increase in the likelihood of shoulder pain. The magnitude of peak proximal force is both correlated to reported shoulder pain and capable of being used to accurately predict the likelihood of experiencing shoulder pain. It appears that those pitchers exhibiting high magnitudes of peak proximal force are significantly more likely to report experiencing shoulder pain than those who generate lower magnitudes of peak proximal force.

  11. Avoiding Shoulder Injury from Resistance Training.

    ERIC Educational Resources Information Center

    Durall, Chris J.; Manske, Robert C.; Davies, George J.

    2001-01-01

    Identifies shoulder exercises commonly performed in fitness centers that may contribute to or exacerbate glenohumeral joint (shoulder) injury, describing alternative exercises that may be substituted and a offering rationale for the variations. The article focuses on anterior and posterior glenohumeral instability, subacromial impingement (primary…

  12. Relationship Between Hand Contact Angle and Shoulder Loading During Manual Wheelchair Propulsion by Individuals with Paraplegia

    PubMed Central

    Mulroy, Sara J.; Ruparel, Puja; Hatchett, Patricia E.; Haubert, Lisa Lighthall; Eberly, Valerie J.; Gronley, JoAnne K.

    2015-01-01

    Background: Shoulder loading during manual wheelchair propulsion (WCP) contributes to the development of shoulder pain in individuals with spinal cord injury (SCI). Objective: To use regression analysis to investigate the relationships between the hand contact angle (location of the hand on the pushrim at initial contact and release during the push phase of the WCP cycle) with propulsion characteristics, pushrim forces, and shoulder kinetics during WCP in individuals with paraplegia. Methods: Biomechanical data were collected from 222 individuals (198 men and 24 women) with paraplegia from SCI during WCP on a stationary ergometer at a self-selected speed. The average age of participants was 34.7 years (±9.3), mean time since SCI was 9.3 years (±6.1), and average body weight was 74.4 kg (±15.9). The majority (n = 127; 56%) of participants had lower level paraplegia (T8 to L5) and 95 (42%) had high paraplegia (T2 to T7). Results: Increased push arc (mean = 75.3°) was associated with greater velocity (R = 0.384, P < .001) and cycle distance (R = 0.658, P < .001) and reduced cadence (R = -0.419, P < .001). Initial contact angle and hand release angles were equally associated with cycle distance and cadence, whereas a more anterior release angle was associated with greater velocity (R = 0.372, P < .001). When controlling for body weight, a more posterior initial contact angle was associated with greater posterior shoulder net joint force (R = 0.229, P = .001) and greater flexor net joint moment (R = 0.204, P = .002), whereas a more anterior hand release angle was significantly associated with increased vertical (R = 0.270, P < .001) and greater lateral (R = .293, P < .001) pushrim forces; greater shoulder net joint forces in all 3 planes — posterior (R = 0.164, P = .015), superior (R = 0.176, P = .009), and medial (R = 0.284, P < .001); and greater external rotator (R = 0.176, P = .009) and adductor (R = 0.259, P = .001) net joint moments. Conclusions: Current

  13. Effect of power-assisted hand-rim wheelchair propulsion on shoulder load in experienced wheelchair users: A pilot study with an instrumented wheelchair.

    PubMed

    Kloosterman, Marieke G M; Buurke, Jaap H; de Vries, Wiebe; Van der Woude, Lucas H V; Rietman, Johan S

    2015-10-01

    This study aims to compare hand-rim and power-assisted hand-rim propulsion on potential risk factors for shoulder overuse injuries: intensity and repetition of shoulder loading and force generation in the extremes of shoulder motion. Eleven experienced hand-rim wheelchair users propelled an instrumented wheelchair on a treadmill while upper-extremity kinematic, kinetic and surface electromyographical data was collected during propulsion with and without power-assist. As a result during power-assisted propulsion the peak resultant force exerted at the hand-rim decreased and was performed with significantly less abduction and internal rotation at the shoulder. At shoulder level the anterior directed force and internal rotation and flexion moments decreased significantly. In addition, posterior and the minimal inferior directed forces and the external rotation moment significantly increased. The stroke angle decreased significantly, as did maximum shoulder flexion, extension, abduction and internal rotation. Stroke-frequency significantly increased. Muscle activation in the anterior deltoid and pectoralis major also decreased significantly. In conclusion, compared to hand-rim propulsion power-assisted propulsion seems effective in reducing potential risk factors of overuse injuries with the highest gain on decreased range of motion of the shoulder joint, lower peak propulsion force on the rim and reduced muscle activity.

  14. Joint Task Force Commander’s Handbook for Peace Operations

    DTIC Science & Technology

    2007-11-02

    medicine personnel •• Legal personnel •• Chaplain ministry team I-11 Mission The Commander for the United Nations Transitional Authority in Cambodia was...VIII, “Public Affairs and Media,” of this Handbook. c. Legal. See Chapter IX, “Legal,” of this Handbook. d. Surgeon “Preventive medicine , veterinary...health of the force, it is important to note that UN accepts World Health Organization Standards for food, water, medicine and immunizations when US

  15. Joint Force Quarterly. Number 14, Winter 1996-97

    DTIC Science & Technology

    1997-03-01

    Mogadishu airport during Restore Hope with USS Rushmore on horizon (U.S. Navy/Joseph Dorey); U.S. European Command (EUCOM)—U.S. and Danish forces...Reductions in medical personnel and funding make effective C4 para- mount . With sea LOCs of 12,000 nau- tical miles, air LOCs of nearly 8,000 miles, and a...The para- mount health service function is pre- ventive medicine. Personnel must deploy in good health and also be kept in that con- dition. The ill

  16. Knee joint angle affects EMG-force relationship in the vastus intermedius muscle.

    PubMed

    Saito, Akira; Akima, Hiroshi

    2013-12-01

    It is not understood how the knee joint angle affects the relationship between electromyography (EMG) and force of four individual quadriceps femoris (QF) muscles. The purpose of this study was to examine the effect of the knee joint angle on the EMG-force relationship of the four individual QF muscles, particularly the vastus intermedius (VI), during isometric knee extensions. Eleven healthy men performed 20-100% of maximal voluntary contraction (MVC) at knee joint angles of 90°, 120° and 150°. Surface EMG of the four QF synergists was recorded and normalized by the root mean square during MVC. The normalized EMG of the four QF synergists at a knee joint angle of 150° was significantly lower than that at 90° and 120° (P < 0.05). Comparing the normalized EMG among the four QF synergists, a significantly lower normalized EMG was observed in the VI at 150° as compared with the other three QF muscles (P < 0.05). These results suggest that the EMG-force relationship of the four QF synergists shifted downward at an extended knee joint angle of 150°. Furthermore, the neuromuscular activation of the VI was the most sensitive to change in muscle length among the four QF synergistic muscles.

  17. Bilateral ground reaction forces and joint moments for lateral sidestepping and crossover stepping tasks.

    PubMed

    Kuntze, Gregor; Sellers, William I; Mansfield, Neil

    2009-01-01

    Racquet sports have high levels of joint injuries suggesting the joint loads during play may be excessive. Sports such as badminton employ lateral sidestepping (SS) and crossover stepping (XS) movements which so far have not been described in terms of biomechanics. This study examined bilateral ground reaction forces and three dimensional joint kinetics for both these gaits in order to determine the demands of the movements on the leading and trailing limb and predict the contribution of these movements to the occurrence of overuse injury of the lower limbs. A force platform and motion-analysis system were used to record ground reaction forces and track marker trajectories of 9 experienced male badminton players performing lateral SS, XS and forward running tasks at a controlled speed of 3 m·s(-1) using their normal technique. Ground reaction force and kinetic data for the hip, knee and ankle were analyzed, averaged across the group and the biomechanical variables compared. In all cases the ground reaction forces and joint moments were less than those experienced during moderate running suggesting that in normal play SS and XS gaits do not lead to high forces that could contribute to increased injury risk. Ground reaction forces during SS and XS do not appear to contribute to the development of overuse injury. The distinct roles of the leading and trailing limb, acting as a generator of vertical force and shock absorber respectively, during the SS and XS may however contribute to the development of muscular imbalances which may ultimately contribute to the development of overuse injury. However it is still possible that faulty use of these gaits might lead to high loads and this should be the subject of future work. Key pointsGround reaction forces and joint moments during lateral stepping are smaller in magnitude than those experienced during moderate running.Force exposure in SS and XS gaits in normal play does not appear to contribute to the development of

  18. Correlation of Shoulder and Elbow Kinetics With Ball Velocity in Collegiate Baseball Pitchers

    PubMed Central

    Post, Eric G.; Laudner, Kevin G.; McLoda, Todd A.; Wong, Regan; Meister, Keith

    2015-01-01

    Context Throwing a baseball is a dynamic and violent act that places large magnitudes of stress on the shoulder and elbow. Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables throughout the throwing motion. However, very little research has directly examined the relationship between these kinetic variables and ball velocity. Objective To examine the correlation of peak ball velocity with elbow-valgus torque, shoulder external-rotation torque, and shoulder-distraction force in a group of collegiate baseball pitchers. Design Cross-sectional study. Setting Motion-analysis laboratory. Patients or Other Participants Sixty-seven asymptomatic National Collegiate Athletic Association Division I baseball pitchers (age = 19.5 ± 1.2 years, height = 186.2 ± 5.7 cm, mass = 86.7 ± 7.0 kg; 48 right handed, 19 left handed). Main Outcome Measure(s) We measured peak ball velocity using a radar gun and shoulder and elbow kinetics of the throwing arm using 8 electronically synchronized, high-speed digital cameras. We placed 26 reflective markers on anatomical landmarks of each participant to track 3-dimensional coordinate data. The average data from the 3 highest-velocity fastballs thrown for strikes were used for data analysis. We calculated a Pearson correlation coefficient to determine the associations between ball velocity and peak elbow-valgus torque, shoulder-distraction force, and shoulder external-rotation torque (P < .05). Results A weak positive correlation was found between ball velocity and shoulder-distraction force (r = 0.257; 95% confidence interval [CI] = 0.02, 0.47; r2 = 0.066; P = .018). However, no significant correlations were noted between ball velocity and elbow-valgus torque (r = 0.199; 95% CI = −0.043, 0.419; r2 = 0.040; P = .053) or shoulder external-rotation torque (r = 0.097; 95% CI = −0.147, 0.329; r2 = 0.009; P = .217). Conclusions Although a weak positive correlation was present between ball velocity

  19. Joint Communications in Support of Joint Task Force South during Operation Just Cause

    DTIC Science & Technology

    1991-01-01

    JACC/CP) to control initial actions by the paratroops and other forces on the grcund using single channel radio. Phase four was "stability force...Marines and paratroops tended to use stand-alone SB-3614As because they were small and fai.rly simple. SB-361 4/TT Telephone Switchboard 0 .. . ...0...t(M0704088) Washington OC 20503 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED 1 1991 Master’s inesis,8-19-90 to 6

  20. Preserving the Illustrated Text. Report of the Joint Task Force on Text and Image.

    ERIC Educational Resources Information Center

    Commission on Preservation and Access, Washington, DC.

    The mission of the Joint Task Force on Text and Image was to inquire into the problems, needs, and methods for preserving images in text that are important for scholarship in a wide range of disciplines and to draw from that exploration a set of principles, guidelines, and recommendations for a comprehensive national strategy for image…

  1. Network-Based Approach to Optimize Personnel Recovery for the Joint Force

    DTIC Science & Technology

    2011-05-26

    NUMBER Andrew M . Smith , Major, USAF 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES...NETWORK-BASED APPROACH TO OPTIMIZE PERSONNEL RECOVERY FOR THE JOINT FORCE by Andrew M . Smith Major, USAF A paper submitted to the

  2. [Current concepts in perinatal brachial plexus palsy. Part 2: late phase. Shoulder deformities].

    PubMed

    Dogliotti, Andrés Alejandro

    2011-10-01

    The incidence of obstetric brachial palsy is high and their sequelaes are frequent. Physiotherapy, microsurgical nerve reconstruction and secondary corrections are used together to improve the shoulder function. The most common posture is shoulder in internal rotation and adduction, because of the antagonist weakness. The muscle forces imbalance over the osteoarticular system, will result in a progressive glenohumeral joint deformity which can be recognized with a magnetic resonance image. Tendon transfers of the internal rotators towards the external abductor/rotator muscles, has good results, but has to be combined with antero-inferior soft-tissue releases, if passive range of motion is limited.

  3. Biomechanics of complex shoulder instability.

    PubMed

    Degen, Ryan M; Giles, Joshua W; Thompson, Stephen R; Litchfield, Robert B; Athwal, George S

    2013-10-01

    Identification and treatment of the osseous lesions associated with complex shoulder instability remains challenging. Further biomechanical testing is required to delineate critical defect values and determine which treatments provide improved glenohumeral joint stability for the various defect sizes, while minimizing the associated complications.

  4. Joint Disorders

    MedlinePlus

    A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, ...

  5. Ultrasound of the shoulder.

    PubMed

    Petranova, Tzvetanka; Vlad, Violeta; Porta, Francesco; Radunovic, Goran; Micu, Mihaela C; Nestorova, Rodina; Iagnocco, Annamaria

    2012-06-01

    Ultrasonography (US) is a helpful imaging tool in the evaluation of the musculoskeletal system. It has some advantages over the other imaging techniques, such as plain radiography, computed tomography and magnetic resonance imaging, represented by the non-invasiveness and multiplanar imaging capability, repeatability, lack of radiation burden, good patient acceptance, and relatively limited costs. US offers an excellent resolution and a possibility for real-time dynamic examination of the joints and surrounding soft tissues, as well as enables monitoring of therapeutic response. The most common clinical indications for US examination of the shoulder are rotator cuff and biceps tendon pathology (tenosynovitis, tendinosis, complete and partial tears, and impingement) and disorders of other soft-tissue structures (joint recesses, bursae, muscles, suprascapular and axillary nerves) as well as bony cortex abnormalities. US is very useful for US-guided procedures (biopsy, joint and bursae aspirations and injections, aspiration and dissolution of calcific tendinosis). The aim of this article is to analyze the current literature about US of the shoulder and to describe both normal and pathological findings.

  6. Analysis of applied forces and electromyography of back and shoulders muscles when performing a simulated hand scaling task.

    PubMed

    Porter, William; Gallagher, Sean; Torma-Krajewski, Janet

    2010-05-01

    Hand scaling is a physically demanding task responsible for numerous overexertion injuries in underground mining. Scaling requires the miner to use a long pry bar to remove loose rock, reducing the likelihood of rock fall injuries. The experiments described in this article simulated "rib" scaling (scaling a mine wall) from an elevated bucket to examine force generation and electromyographic responses using two types of scaling bars (steel and fiberglass-reinforced aluminum) at five target heights ranging from floor level to 176 cm. Ten male and six female subjects were tested in separate experiments. Peak and average force applied at the scaling bar tip and normalized electromyography (EMG) of the left and right pairs of the deltoid and erectores spinae muscles were obtained. Work height significantly affected peak prying force during scaling activities with highest force capacity at the lower levels. Bar type did not affect force generation. However, use of the lighter fiberglass bar required significantly more muscle activity to achieve the same force. Results of these studies suggest that miners scale points on the rock face that are below their knees, and reposition the bucket as often as necessary to do so.

  7. Development of 1-DOF manipulator with variable rheological joint for instantaneous force

    NASA Astrophysics Data System (ADS)

    Majima, T.; Nagai, S.; Tomori, H.; Nakamura, T.

    2013-02-01

    Highly rigid actuators such as a geared motor or hydraulic actuator are widely used in industrial robots. To obtain high-speed motion, actuators need to increase the actuator output. However, to increase high-rigidity actuators output, it is necessary to make actuators larger. In contrast, humans perform motions with instantaneous force such as jumping or throwing by using muscles. These instantaneous forces are realized by accumulating potential energy to the muscles and the muscles releasing the energy in a short time. Therefore, in this study a 1-DOF manipulator with variable rheological joint for instantaneous force using an artificial muscle and a magnetorheological (MR) brake was developed. In this paper, the method of generating instantaneous force for this manipulator was proposed. Further, the experiment of the proposed method was also conducted. As a result, generating instantaneous force by proposed method was realized.

  8. Biomechanics of first ray hypermobility: an investigation on joint force during walking using finite element analysis.

    PubMed

    Wong, Duo Wai-Chi; Zhang, Ming; Yu, Jia; Leung, Aaron Kam-Lun

    2014-11-01

    Hypermobility of the first ray is suggested to contribute to hallux valgus. The investigation of first ray hypermobility focused on the mobility and range of motion that based on manual examination. The load transfer mechanism of the first ray is important to understand the development and pathomechanism of hallux valgus. In this study, we investigated the immediate effect of the joint hypermobility on the metatarsocuneiform and metatarsophalangeal joint loading through a reduction of the stiffness of the foot ligaments. A three-dimensional foot model was constructed from a female aged 28 via MRI. All foot and ankle bones, including two sesamoids and the encapsulated bulk tissue were modeled as 3D solid parts, linking with ligaments of shell elements and muscles connectors. The stance phase of walking was simulated by the boundary and loading conditions obtained from gait analysis of the same subject. Compared with the normal foot, the hypermobile foot had higher resultant metatarsocuneiform and metatarsophalangeal joint forces. The increases accounted for 18.6% and 3.9% body weight. There was also an abrupt change of metatarsocuneiform joint force in the medial-lateral direction. The predicted results represented possible risk of joint problems and metatarsus primus varus.

  9. Forces in bolted joints: analysis methods and test results utilized for nuclear core applications (LWBR Development Program)

    SciTech Connect

    Crescimanno, P.J.; Keller, K.L.

    1981-03-01

    Analytical methods and test data employed in the core design of bolted joints for the LWBR core are presented. The effects of external working loads, thermal expansion, and material stress relaxation are considered in the formulation developed to analyze joint performance. Extensions of these methods are also provided for bolted joints having both axial and bending flexibilities, and for the effect of plastic deformation on internal forces developed in a bolted joint. Design applications are illustrated by examples.

  10. Measurement of force sense reproduction in the knee joint: application of a new dynamometric device

    PubMed Central

    Zavieh,, Minoo Khalkhali; Amirshakeri,, Bahram; Rezasoltani,, Asghar; Talebi,, Ghadam Ali; Kalantari,, Khosro Khademi; Nedaey,, Vahab; Baghban,, Alireza Akbarzadeh

    2016-01-01

    [Purpose] The aim of this study was to determine the reliability of a newly designed dynamometric device for use in frequent force producing/reproducing tasks on the knee joint. [Subjects and Methods] In this cross-sectional study (Development & Reliability), 30 young healthy males and females (age 23.4 ± 2.48 years) were selected among students of Tabriz University of Medical Sciences by simple randomized selection. The study instrument was designed to measure any isometric contraction force exerted by the knee joint flexor/extensor muscles, known as the ipsilateral and contralateral methods. Participant knees were fixed in 60° flexion, and each participant completed the entire set of measurements twice, 72 hours apart. [Results] The findings showed a good intraclass correlation coefficient of 0.73 to 0.81 for all muscle groups. The standard error of measurement and smallest detectable difference for flexor muscle groups were 0.37 and 1.02, respectively, while the values increased to standard error of measurement=0.38 and smallest detectable difference=1.05 for extensor muscle groups. [Conclusion] The device designed could quantify the forces producing/reproducing tasks on the knee joint with a high rate of reliability, and can probably be applied for outcome measurements in proprioceptive assessment of the knee joint. PMID:27630421

  11. Joint Campaign Design: Using a Decide-Detect-Attack (DDA) Methodology to Synchronize the Joint Force’s Capabilities Against Enemy Centers of Gravity

    DTIC Science & Technology

    1994-05-06

    of COG. USMC DOCTRINE Field Marine Force Manual (FMFM) 1, Warfifhtinf, contains the USMC’s keystone doctrine. An examination of this manual reveals...Joint Publication (JP) 3-0, Doctrine for Unified and Joint Onerations. JP 3-0 is the keystone manual that sets forth the doctrine to govern unified and...seaways, rails, lines of communication, pipelines , and numerous other facilities needed to support the fielded military forces.m’ The next most critical

  12. A novel cadaveric model for anterior-inferior shoulder dislocation using forcible apprehension positioning.

    PubMed

    McMahon, Patrick J; Chow, Stephen; Sciaroni, Laura; Yang, Bruce Y; Lee, Thay Q

    2003-01-01

    A novel cadaveric model for anterior-inferior shoulder dislocation using forcible apprehension positioning is presented. This model simulates an in vivo mechanism and yields capsulolabral lesions. The scapulae of 14 cadaveric entire upper limbs (82 +/- 9 years, mean +/- standard deviation) were each rigidly fixed to a custom shoulder-testing device. A pneumatic system was used with pulleys and cables to simulate the rotator cuff and the deltoid muscles (anterior and middle portions). The glenohumeral joint was then positioned in the apprehension position of abduction, external rotation, and horizontal abduction. A 6-degree-of-freedom load cell (Assurance Technologies, Garner, North Carolina) measured the joint reaction force that was then resolved into three orthogonal components of compression force, anteriorly directed force, and superiorly directed force. With the use of a thrust bearing, the humerus was moved along a rail with a servomotor-controlled system at 50 mm/s that resulted in horizontal abduction. Force that developed passively in the pectoralis major muscle was recorded with an independent uniaxial load cell. Each of the glenohumeral joints dislocated anterior-inferior, six with avulsion of the capsulolabrum from the anterior-inferior glenoid bone and eight with capsulolabral stretching. Pectoralis major muscle force as well as the joint reaction force increased with horizontal abduction until dislocation. At dislocation, the magnitude of the pectoralis major muscle force, 609.6 N +/- 65.2 N was similar to the compression force, 569.6 N +/- 37.8 N. A cadaveric model yielded an anterior dislocation with a mechanism of forcible apprehension positioning when the appropriate shoulder muscles were simulated and a passive pectoralis major muscle was included. Capsulolabral lesions resulted, similar to those observed in vivo.

  13. Advance Force Operations: The Middleweight Force’s Essential Role in the Joint Operations

    DTIC Science & Technology

    2013-04-18

    disclose if emplacements were manned or reveal carefully camouflaged machinegun positions: "Against an alert enemy the attacker will have to depend...Joint Chiefs of Staff and the primary responsibilities of the US Marine Corps.35 …the destruction of hostile weather and radar stations, destruction of...101 Interview with LTG Frank Helmick, XVIII Airborne Corps Commander during the 2011 US Army Reconnaissance Symposium . He commented that his AFO

  14. Force-velocity Relationship of Muscles Performing Multi-joint Maximum Performance Tasks.

    PubMed

    Jaric, S

    2015-08-01

    Manipulation of external loads typically provides a range of force, velocity, and power data that allows for modeling muscle mechanical characteristics. While a typical force-velocity relationship obtained from either in vitro muscles or isolated muscle groups can be described by a hyperbolic equation, the present review paper reveals the evidence that the same relationship obtained from maximum-performance multi-joint movements could be approximately linear. As a consequence, this pattern also results in a relatively simple shape of the power-velocity relationship. The parameters of the linear force-velocity relationship reveal the maximum force, velocity and power. Recent studies conducted on various functional movement tasks reveal that these parameters could be reliable, on average moderately valid, and typically sensitive enough to detect differences among populations of different physical abilities. Therefore, the linear force-velocity relationship together with the associated parabolic power-velocity relationship could provide both a new and simplified approach to studies of the design and function of human muscular system and its modeling. Regarding the practical applications, the reviewed findings also suggest that the loaded multi-joint movements could be developed into relatively simple routine tests of the force-, velocity- and power-generating capacity of the neuromuscular system.

  15. How critical are the tibiofemoral joint reaction forces during frequent squatting in Asian populations?

    PubMed

    Thambyah, Ashvin

    2008-08-01

    This study examines tibiofemoral joint moments and forces when performing a squat. The relevance of studying such an activity is to understand better the mechanical factors involved in the higher incidence of tibiofemoral osteoarthritis in Asian populations where squatting is a common daily activity. In this study, motion analysis data of walking versus squatting were compared, specifically looking at net external knee flexion moments, ground reaction forces and tibiofemoral contact forces. It was found that while squatting resulted in more than 2.5 times larger peak external moments compared with walking, tibiofemoral contact forces were not significantly different. This was due to reduced ground reaction forces recorded for the squatting phase compared to the larger dynamic effects of deceleration at heel strike during walking. The most significant finding of this study was that in squatting, there was a reversal in the tibiofemoral shear reaction force from posterior-directed to anterior-directed, occurring under full compressive load and within a fraction of a second. It is believed that repeated squatting results in many such reversals in shear reactions that may ultimately have significant implications to the long term mechanical function and structural integrity of the joint cartilage.

  16. The influence of elbow joint angle on different phases of force development during maximal voluntary contraction.

    PubMed

    Jaskólski, A; Kisiel, K; Adach, Z; Jaskólska, A

    2000-12-01

    The first aim of the study was to find an elbow joint angle at which muscle can produce maximum voluntary force (Lo(MVC)) and to compare that angle with an angle at which the fastest rates of force development occur (Lo). The second aim of the study was to find if changes in MVC and force development speed at an angle smaller (Ls) and larger (Ll) than the optimal angle depend on whether Ls and Ll were compared to Lo or Ls and Ll to Lo(MVC). Twenty-four male physical education students were tested four times using the BIODYNA dynamometer to measure torque versus time at an optimal length, as well as at lengths that were shorter (Ls = optimal -30 degrees) and longer (Ll = optimal +50 degrees). The average values of optimal angles for force development indices (Lo) were similar to the angle at which maximum force was produced (Lo(MVC)); however, there was a small (5-10 degrees) difference between Lo and Lo(MVC) in the majority of subjects. The results showed that during elbow flexion with the forearm in the midrange position, the difference between Lo and Lo(MVC) was small and did not affect MVC; however, it had a significant effect on the relation between joint angle and force development speed.

  17. The influence of the spine on the shoulder in the throwing athlete.

    PubMed

    Young, J L; Herring, S A; Press, J M; Casazza, B A

    1996-01-01

    Analysis of shoulder dysfunction in throwing and overhead athletes can no longer be restricted to evaluation of the glenohumeral joint alone. The isolated shoulder is incapable of generating the force necessary to hurl a baseball at velocities of 90-100 miles per hour or serve a tennis ball in excess of 120 miles per hour. The purpose of this paper is to provide a literature based theoretical framework for the role of the spine during these activities. The spine is a pivotal component of the kinematic chain which functions as a transfer link between the lower and upper limbs, a force generator capable of accelerating the arm, and a force attenuator which dampens shear forces at the glenohumeral joint during the deceleration phase of the pitching motion. Side bending and rotation of the cervical spine facilitates visual acquisition of the intended target. Inflexibility of the hip musculature and weakness of the muscles which attach to the thoracolumbar fascia have profound effects upon spine function which secondarily places greater stress upon the glenohumeral joint and rotator cuff. Shoulder rehabilitation and injury prevention programs should include evaluation of and exercise regimens for the lumbar, thoracic and cervical spine.

  18. Navy Information Dominance, the Battle of Midway, and the Joint Force Commander: It Worked Then, It Needs to Work Now

    DTIC Science & Technology

    2013-05-19

    cyberspace, is putting increased emphasis on the need for the Joint Force Commander to employ his force to achieve Information Dominance . The information... Information Dominance is to assist in achieving Decision Superiority, Assured Command and Control, Battlespace Awareness, and Integrated Fires. Navy... Information Dominance aims to use information in cyberspace as a way and means in warfare -- as a battery in the Joint Force Commander’s arsenal. The

  19. The Joint Force Air Component Commander and the Integration of Offensive Cyberspace Effects: Power Projection through Cyberspace

    DTIC Science & Technology

    2016-06-14

    Air & Space Power Journal The Joint Force Air Component Commander and the Integration of Offensive Cyberspace Effects Power Projection through...and Space Power Journal requests a courtesy line. Cyberspace can provide great opportunities to assist the joint force air compo-nent commander (JFACC...integration of offensive cyberspace operations is best understood by examining forces presented in the cyberspace domain as a peer component to the

  20. Neurohistological examination of the inferior glenohumeral ligament of the shoulder.

    PubMed

    Steinbeck, Jörn; Brüntrup, Jens; Greshake, Oliver; Pötzl, Wolfgang; Filler, Timm; Liljenqvist, Ulf

    2003-03-01

    The neural histology of the anterior band of the inferior glenohumeral ligament (IGHL) was studied in 11 fresh shoulder specimen using a special silver impregnation technique. Between the collagen fibers small myelinated and unmyelinated dendrites could be detected. The appearance of neurovascular structures in the adjacent synovial layer clearly exceeded the typical supply to soft tissues. Analysing about 11,000 sections Ruffini mechanoreceptors that are known to be slow adapting were found on the humeral insertion of the band. The sections containing these neural end organs were identified by means of transillumination and reflection-contrast microscopy and reconstructed using three-dimensional image processing. The presence of neural structures including Ruffini corpuscles in these most important passive stabilizers of the shoulder joint shows that these ligaments function also as an active safety device. There slow adaption is a prerequisite for muscular reflexes counteracting the tensile stresses to which the passive stabilizing structures of the shoulder are exposed. A disruption of the continuity of these structures by mechanical forces or surgery can reduce the biofeedback and proprioceptive quality and thus lead to a decrease of shoulder function and/or stability. These observations should be taken into account when planning surgical interventions involving the IGHL. Procedures like capsule shifts or plications may affect mechanoreceptor orientation and concentrations, thereby affecting the interaction between these structures and the synergistic muscles. When possible, these intervention should avoid receptor-dense regions while attempting to restore normal anatomical orientation and tissue tension.

  1. Age and gender differences in the control of vertical ground reaction force by the hip, knee and ankle joints.

    PubMed

    Toda, Haruki; Nagano, Akinori; Luo, Zhiwei

    2015-06-01

    [Purpose] This study examined the relationships between joint moment and the control of the vertical ground reaction force during walking in the elderly and young male and female individuals. [Subjects and Methods] Forty elderly people, 65 years old or older (20 males and 20 females), and 40 young people, 20 to 29 years old (20 males and 20 females), participated in this study. Joint moment and vertical ground reaction force during walking were obtained using a 3D motion analysis system and force plates. Stepwise linear regression analysis determined the joint moments that predict the amplitude of the vertical ground reaction force. [Results] Knee extension moment was related to the vertical ground reaction force in the young males and females. On the other hand, in the elderly females, hip, ankle, and knee joint moments were related to the first peak and second peak forces, and the minimum value of vertical ground reaction force, respectively. [Conclusion] Our results suggest that the young males and females make use of the knee joint moment to control of the vertical ground reaction force. There were differences between the elderly and the young females with regard to the joints used for the control of the vertical ground reaction force.

  2. Finnishing the Force: Achieving True Flexibility for the Joint Force Commander

    DTIC Science & Technology

    2014-06-01

    CREW) 2.1 vehicle-mounted jammer (up to 25,000 of which are on contract for purchase by the US Army). It uses a digitally controlled, 30-watt...out assigned tasks. We may no longer be able to afford the luxury of retaining our most sophisticated capabilities as or- ganic elements of a...joint force” (II-7). 2. “JCREW: ITT Wins Contracts for Land Mine Jammers,” Defense Industry Daily, 3 Octo- ber 2011, http://www.defenseindustrydaily.com

  3. Shoulder replacement - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000178.htm Shoulder replacement - discharge To use the sharing features on this page, please enable JavaScript. You had shoulder replacement surgery to replace the bones of your shoulder ...

  4. 49 CFR 572.184 - Shoulder assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the plane of motion of the impactor at contact with the shoulder. The arms are oriented forward at 50... ±5 mm. The length of the elastic shoulder cord (175-3015) shall be adjusted so that a force between... clavicle in the same plane as the clavicle movement, is required to initiate a forward motion of 1 to 5...

  5. Airpower in Hybrid War: Ethical Implications for the Joint Force Commander

    DTIC Science & Technology

    2014-05-15

    an ever enticing means to achieve the nation’s political objectives. Applying airpower to hybrid war raises unique ethical considerations for the...Airpower 3 Hierarchical Ethics in Applying Airpower to Hybrid War 5 Double Intent—A Consideration in Proportionality 8...hybrid war raises unique ethical considerations for the Joint Force Commander (JFC). In this essay, the author introduces the nuances of hybrid war, the

  6. Regional Engagement from Phase 0: A Joint Interagency Task Force for the Trans-Sahel

    DTIC Science & Technology

    2006-05-16

    are woven throughout the NSS. For most of Africa, the Commander, United States European Command (EUCOM), executes those NSS tasks which fall under ...hinges critically on reaching favorable agreements with those entities. New, and key to this construct, is a DoS Trans- Sahel officer. The State ...FINAL 3. DATES COVERED (From - To) Regional Engagement from Phase 0: A Joint Interagency Task Force for the Trans- Sahel 5a

  7. Comparison of Upper Limb Joint Forces During Straight Line and Turning Wheelchair Maneuvers

    DTIC Science & Technology

    2007-11-02

    maneuvers. A high incidence of musculoskeletal injuries has been reported due to the overuse and high repetitive motion of wrist, elbow and shoulder...propulsion, upper extremities are the major source of power. Owing to the overuse and high repetitive motion of the wrist, elbow and shoulder, high...environment, turning motion is frequently performed. This repetitive movement could generate unwanted stresses at the wrist, elbow and shoulder

  8. Adhesive capsulitis of the shoulder.

    PubMed

    Neviaser, Andrew S; Neviaser, Robert J

    2011-09-01

    Adhesive capsulitis is characterized by painful, gradual loss of active and passive shoulder motion resulting from fibrosis and contracture of the joint capsule. Other shoulder pathology can produce a similar clinical picture, however, and must be considered. Management is based on the underlying cause of pain and stiffness, and determination of the etiology is essential. Subtle clues in the history and physical examination can help differentiate adhesive capsulitis from other conditions that cause a stiff, painful shoulder. The natural history of adhesive capsulitis is a matter of controversy. Management of true capsular restriction of motion (ie, true adhesive capsulitis) begins with gentle, progressive stretching exercises. Most patients improve with nonsurgical treatment. Indications for surgery should be individualized. Failure to obtain symptomatic improvement and continued functional disability following ≥6 months of physical therapy is a general guideline for surgical intervention. Diligent postoperative therapy to maintain motion is required to minimize recurrence of adhesive capsulitis.

  9. Simultaneous shoulder and elbow dislocation.

    PubMed

    Cobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-05-23

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice.

  10. Simultaneous shoulder and elbow dislocation

    PubMed Central

    Çobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-01-01

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice. PMID:24859563

  11. Hip Joint Contact Force in the Emu (Dromaius novaehollandiae) during Normal Level Walking

    PubMed Central

    Goetz, Jessica E.; Derrick, Timothy R.; Pedersen, Douglas R.; Robinson, Duane A.; Conzemius, Michael G.; Baer, Thomas E.; Brown, Thomas D.

    2008-01-01

    The emu is a large, (bipedal) flightless bird that potentially can be used to study various orthopaedic disorders in which load protection of the experimental limb is a limitation of quadrupedal models. An anatomy-based analysis of normal emu walking gait was undertaken to determine hip contact forces for comparison with human data. Kinematic and kinetic data captured for two laboratory-habituated emus were used to drive the model. Muscle attachment data were obtained by dissection, and bony geometries were obtained by CT scan. Inverse dynamics calculations at all major lower-limb joints were used in conjunction with optimization of muscle forces to determine hip contact forces. Like human walking gait, emu ground reaction forces showed a bimodal distribution over the course of the stance phase. Two-bird averaged maximum hip contact force was approximately 5.5 times body weight, directed nominally axially along the femur. This value is only modestly larger than optimization-based hip contact forces reported in literature for humans. The interspecies similarity in hip contact forces makes the emu a biomechanically attractive animal in which to model loading-dependent human orthopaedic hip disorders. PMID:18206892

  12. Shoulder Strength and Physical Activity Predictors of Shoulder Pain in People With Paraplegia From Spinal Injury: Prospective Cohort Study

    PubMed Central

    Hatchett, Patricia; Eberly, Valerie J.; Lighthall Haubert, Lisa; Conners, Sandy; Requejo, Philip S.

    2015-01-01

    Background Shoulder joint pain is a frequent secondary complaint for people following spinal cord injury (SCI). Objective The purpose of this study was to determine predictors of shoulder joint pain in people with paraplegia. Methods/Design A 3-year longitudinal study was conducted. Participants were people with paraplegia who used a manual wheelchair for at least 50% of their mobility and were asymptomatic for shoulder pain at study entry. Participants were classified as having developed shoulder pain if they experienced an increase of ≥10 points on the Wheelchair User's Shoulder Pain Index in the 3-year follow-up period. Measurements of maximal isometric shoulder torques were collected at study entry (baseline), 18 months, and 3 years. Daily activity was measured using a wheelchair odometer, and self-reported daily transfer and raise frequency data were collected by telephone every 6 weeks. Results Two hundred twenty-three participants were enrolled in the study; 39.8% developed shoulder pain over the 3-year follow-up period. Demographic variables and higher activity levels were not associated with shoulder pain onset. Baseline maximal isometric torque (normalized by body weight) in all shoulder muscle groups was 10% to 15% lower in participants who developed shoulder pain compared with those who remained pain-free. Lower shoulder adduction torque was a significant predictor of shoulder pain development (log-likelihood test=11.38), but the model explained only 7.5% of shoulder pain onset and consequently is of limited clinical utility. Limitations Time since SCI varied widely among participants, and transfer and raise activity was measured by participant recall. Conclusions Participants who developed shoulder pain had decreased muscle strength, particularly in the shoulder adductors, and lower levels of physical activity prior to the onset of shoulder pain. Neither factor was a strong predictor of shoulder pain onset. PMID:25721123

  13. Strength Training and Shoulder Proprioception

    PubMed Central

    Salles, José Inácio; Velasques, Bruna; Cossich, Victor; Nicoliche, Eduardo; Ribeiro, Pedro; Amaral, Marcus Vinicius; Motta, Geraldo

    2015-01-01

    Context: Proprioception is essential to motor control and joint stability during daily and sport activities. Recent studies demonstrated that athletes have better joint position sense (JPS) when compared with controls matched for age, suggesting that physical training could have an effect on proprioception. Objective: To evaluate the result of an 8-week strength-training program on shoulder JPS and to verify whether using training intensities that are the same or divergent for the shoulder's dynamic-stabilizer muscles promote different effects on JPS. Design: Randomized controlled clinical trial. Setting: We evaluated JPS in a research laboratory and conducted training in a gymnasium. Patients or Other Participants: A total of 90 men, right handed and asymptomatic, with no history of any type of injury or shoulder instability. Intervention(s): For 8 weeks, the participants performed the strength-training program 3 sessions per week. We used 4 exercises (bench press, lat pull down, shoulder press, and seated row), with 2 sets each. Main Outcome Measure(s): We measured shoulder JPS acuity by calculating the absolute error. Results: We found an interaction between group and time. To examine the interaction, we conducted two 1-way analyses of variance comparing groups at each time. The groups did not differ at pretraining; however, a difference among groups was noted posttraining. Conclusions: Strength training using exercises at the same intensity produced an improvement in JPS compared with exercises of varying intensity, suggesting that the former resulted in improvements in the sensitivity of muscle spindles and, hence, better neuromuscular control in the shoulder. PMID:25594912

  14. Gimballed Shoulders for Friction Stir Welding

    NASA Technical Reports Server (NTRS)

    Carter, Robert; Lawless, Kirby

    2008-01-01

    In a proposed improvement of tooling for friction stir welding, gimballed shoulders would supplant shoulders that, heretofore, have been fixedly aligned with pins. The proposal is especially relevant to self-reacting friction stir welding. Some definitions of terms, recapitulated from related prior NASA Tech Briefs articles, are prerequisite to a meaningful description of the proposed improvement. In friction stir welding, one uses a tool that includes (1) a rotating shoulder on top (or front) of the workpiece and (2) a pin that rotates with the shoulder and protrudes from the shoulder into the depth of the workpiece. In conventional friction stir welding, the main axial force exerted by the tool on the workpiece is reacted through a ridged backing anvil under (behind) the workpiece. When conventional friction stir welding is augmented with an auto-adjustable pin-tool (APT) capability, the depth of penetration of the pin into the workpiece is varied in real time by a position- or forcecontrol system that extends or retracts the pin as needed to obtain the desired effect. In self-reacting (also known as self-reacted) friction stir welding as practiced heretofore, there are two shoulders: one on top (or front) and one on the bottom (or back) of the workpiece. In this case, a threaded shaft protrudes from the tip of the pin to beyond the back surface of the workpiece. The back shoulder is held axially in place against tension by a nut on the threaded shaft. Both shoulders rotate with the pin and remain aligned coaxially with the pin. The main axial force exerted on the workpiece by the tool and front shoulder is reacted through the back shoulder and the threaded shaft into the friction-stir-welding machine head, so that a backing anvil is no longer needed. A key transmits torque between the bottom shoulder and the threaded shaft, so that the bottom shoulder rotates with the shaft. This concludes the prerequisite definitions of terms.

  15. Prognostic Factors in Arthroplasty in the Rheumatoid Shoulder

    PubMed Central

    Nagels, Jochem; Rozing, Maarten P.

    2010-01-01

    Total shoulder arthroplasty is commonly considered a good option for treatment of the rheumatoid shoulder. However, when the rotator cuff and glenoid bone stock are not preserved, the clinical outcome of arthroplasty in the rheumatoid patients remains unclear. Aim of the study is to explore the prognostic value of multiple preoperative and peroperative variables in total shoulder arthroplasty and shoulder hemiarthroplasty in rheumatoid patients. Clinical Hospital for Special Surgery Shoulder score was determined at different time points over a mean period of 6.5 years in 66 rheumatoid patients with total shoulder arthroplasty and 75 rheumatoid patients with shoulder hemiarthroplasty. Moreover, radiographic analysis was performed to assess the progression of humeral head migration and glenoid loosening. Advanced age and erosions or cysts at the AC joint at time of surgery were associated with a lower postoperative Clinical Hospital for Special Surgery Shoulder score. In total shoulder arthroplasty, status of the rotator cuff and its repair at surgery were predictive of postoperative improvement. Progression of proximal migration during the period after surgery was associated with a lower clinical score over time. However, in hemiarthroplasty, no relation was observed between the progression of proximal or medial migration during follow-up and the clinical score over time. Status of the AC joint and age at the time of surgery should be taken into account when considering shoulder arthroplasty in rheumatoid patients. Total shoulder arthroplasty in combination with good cuff repair yields comparable clinical results as total shoulder arthroplasty when the cuff is intact. PMID:21423883

  16. Shoulder arthroscopy

    MedlinePlus

    ... ball and socket joint) A torn or damaged biceps tendon A torn rotator cuff A bone spur ... repair. Using arthroscopy for rotator cuff repairs or tendinitis usually relieves the pain, but you may not ...

  17. Arthroscopic Findings in Anterior Shoulder Instability

    PubMed Central

    Hantes, Michael; Raoulis, Vasilios

    2017-01-01

    Background: In the last years, basic research and arthroscopic surgery, have improved our understanding of shoulder anatomy and pathology. It is a fact that arthroscopic treatment of shoulder instability has evolved considerably over the past decades. The aim of this paper is to present the variety of pathologies that should be identified and treated during shoulder arthroscopy when dealing with anterior shoulder instability cases. Methods: A review of the current literature regarding arthroscopic shoulder anatomy, anatomic variants, and arthroscopic findings in anterior shoulder instability, is presented. In addition, correlation of arthroscopic findings with physical examination and advanced imaging (CT and MRI) in order to improve our understanding in anterior shoulder instability pathology is discussed. Results: Shoulder instability represents a broad spectrum of disease and a thorough understanding of the pathoanatomy is the key for a successful treatment of the unstable shoulder. Patients can have a variety of pathologies concomitant with a traditional Bankart lesion, such as injuries of the glenoid (bony Bankart), injuries of the glenoid labrum, superiorly (SLAP) or anteroinferiorly (e.g. anterior labroligamentous periosteal sleeve avulsion, and Perthes), capsular lesions (humeral avulsion of the glenohumeral ligament), and accompanying osseous-cartilage lesions (Hill-Sachs, glenolabral articular disruption). Shoulder arthroscopy allows for a detailed visualization and a dynamic examination of all anatomic structures, identification of pathologic findings, and treatment of all concomitant lesions. Conclusion: Surgeons must be well prepared and understanding the normal anatomy of the glenohumeral joint, including its anatomic variants to seek for the possible pathologic lesions in anterior shoulder instability during shoulder arthroscopy. Patient selection criteria, improved surgical techniques, and implants available have contributed to the enhancement of

  18. Subject-specific hip geometry affects predicted hip joint contact forces during gait.

    PubMed

    Lenaerts, G; De Groote, F; Demeulenaere, B; Mulier, M; Van der Perre, G; Spaepen, A; Jonkers, I

    2008-01-01

    Hip loading affects bone remodeling and implant fixation. In this study, we have analyzed the effect of subject-specific modeling of hip geometry on muscle activation patterns and hip contact forces during gait, using musculoskeletal modeling, inverse dynamic analysis and static optimization. We first used sensitivity analysis to analyze the effect of isolated changes in femoral neck-length (NL) and neck-shaft angle (NSA) on calculated muscle activations and hip contact force during the stance phase of gait. A deformable generic musculoskeletal model was adjusted incrementally to adopt a physiological range of NL and NSA. In a second similar analysis, we adjusted hip geometry to the measurements from digitized radiographs of 20 subjects with primary hip osteoarthrosis. Finally, we studied the effect of hip abductor weakness on muscle activation patterns and hip contact force. This analysis showed that differences in NL (41-74 mm) and NSA (113-140 degrees ) affect the muscle activation of the hip abductors during stance phase and hence hip contact force by up to three times body weight. In conclusion, the results from both the sensitivity and subject-specific analysis showed that at the moment of peak contact force, altered NSA has only a minor effect on the loading configuration of the hip. Increased NL, however, results in an increase of the three hip contact-force components and a reduced vertical loading. The results of these analyses are essential to understand modified hip joint loading, and for planning hip surgery for patients with osteoarthrosis.

  19. Arthroscopic Management of Anterior, Posterior, and Multidirectional Shoulder Instabilities.

    PubMed

    Field, Larry D; Ryu, Richard K N; Abrams, Jeffrey S; Provencher, Matthew

    2016-01-01

    Arthroscopic shoulder stabilization offers several potential advantages compared with open surgery, including the opportunity to more accurately evaluate the glenohumeral joint at the time of diagnostic assessment; comprehensively address multiple pathologic lesions that may be identified; and avoid potential complications unique to open stabilization, such as postoperative subscapularis failure. A thorough understanding of normal shoulder anatomy and biomechanics, along with the pathoanatomy responsible for anterior, posterior, and multidirectional shoulder instability patterns, is very important in the management of patients who have shoulder instability. The treating physician also must be familiar with diagnostic imaging and physical examination maneuvers that are required to accurately diagnose shoulder instability.

  20. Shoulder arthroplasty in osteoarthritis: current concepts in biomechanics and surgical technique

    PubMed Central

    Merolla, G; Nastrucci, G; Porcellini, G

    Shoulder arthroplasty is a technically demanding procedure to restore shoulder function in patients with severe osteoarthritis of the glenohumeral joint. The modern prosthetic system exploit the benefits of modularity and the availibility of additional sizes of the prosthetic components. In this paper we describe the biomechanics of shoulder arthroplasty and the technique for shoulder replacement including total shoulder arthroplasty (TSA) with all-polyethylene and metal-backed glenoid component, humeral head resurfacing and stemless humeral replacement. PMID:24251240

  1. Shoulder arthroplasty in osteoarthritis: current concepts in biomechanics and surgical technique.

    PubMed

    Merolla, G; Nastrucci, G; Porcellini, G

    2013-01-01

    Shoulder arthroplasty is a technically demanding procedure to restore shoulder function in patients with severe osteoarthritis of the glenohumeral joint. The modern prosthetic system exploit the benefits of modularity and the availibility of additional sizes of the prosthetic components. In this paper we describe the biomechanics of shoulder arthroplasty and the technique for shoulder replacement including total shoulder arthroplasty (TSA) with all-polyethylene and metal-backed glenoid component, humeral head resurfacing and stemless humeral replacement.

  2. Elbow joint stability in relation to forced external rotation: An experimental study of the osseous constraint.

    PubMed

    Deutch, Søren R; Jensen, Steen L; Olsen, Bo S; Sneppen, Otto

    2003-01-01

    The objective of this study was to evaluate the osseous constraint related to forced forearm external rotation as the initial stage in a posterior elbow dislocation. Six joint specimens without soft tissues were examined in a joint analysis system developed for simulation of dislocation. The osseous stability, expressed as the maximal torque needed for pathologic external forearm rotation, increased from varus to valgus stress (P =.0001) and from 10 degrees to 90 degrees of elbow flexion (P =.012) and also tended to increase from forearm supination to pronation. The work of pathologic external forearm rotation until the point of maximal torque decreased from a maximum in full extension to a minimum at 30 degrees of elbow flexion (P =.03). The elbow in a slightly flexed position, varus stress, and forearm external rotation trauma might be the important biomechanical factors in the posterior elbow dislocation, and they might serve as guidelines during clinical investigation for posterolateral instability.

  3. Throwing, the Shoulder, and Human Evolution.

    PubMed

    Kuhn, John E

    2016-01-01

    Throwing with accuracy and speed is a skill unique to humans. Throwing has many advantages and the ability to throw has likely been promoted through natural selection in the evolution of humans. There are many unsolved questions regarding the anatomy of the human shoulder. The purpose of this article is to review many of these mysteries and propose that the answer to these questions can be understood if one views the shoulder as a joint that has evolved to throw.

  4. Pain mapping for common shoulder disorders.

    PubMed

    Bayam, Levent; Ahmad, Mudussar A; Naqui, Syed Z; Chouhan, Aroonkumar; Funk, Lennard

    2011-07-01

    We conducted a study to ascertain specific patterns of pain in patients with common shoulder disorders and to describe a comprehensive shoulder pain map. We prospectively studied 94 cases involving an upper limb pain map and correlated the maps with the final diagnoses made by 2 clinicians who were blinded to the pain map findings. Pattern, severity, and type of pain were specific to each common shoulder disorder. In subacromial impingement, pain was predominantly sharp, occurred around the anterior aspect of the shoulder, radiated down the arm, and was associated with dull, aching pain radiating to the hand. A similar pain pattern was found in rotator cuff tears. In acromioclavicular joint pathology, pain was sharp, stabbing, and well localized to the anterosuperior shoulder area. Glenohumeral joint arthritis was marked by the most severe pain, which occurred in a mixed pattern and affected the entire arm. Whereas the pain of instability was a mixture of sharp and dull pain, the pain of calcific tendonitis was severe and sharp. Both pains were limited to the upper arm and shoulder. Pain mapping revealed definitive patterns for shoulder pathologies. We advocate using pain maps as useful diagnostic guides and research tools.

  5. AAPM/SNMMI Joint Task Force: report on the current state of nuclear medicine physics training.

    PubMed

    Harkness, Beth A; Allison, Jerry D; Clements, Jessica B; Coffey, Charles W; Fahey, Frederic H; Gress, Dustin A; Kinahan, Paul E; Nickoloff, Edward L; Mawlawi, Osama R; MacDougall, Robert D; Pizzutiello, Robert J

    2015-09-08

    The American Association of Physicists in Medicine (AAPM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) recognized the need for a review of the current state of nuclear  medicine physics training and the need to explore pathways for improving nuclear medicine physics training opportunities. For these reasons, the two organizations formed a joint AAPM/SNMMI Ad Hoc Task Force on Nuclear Medicine Physics  Training. The mission of this task force was to assemble a representative group of stakeholders to:• Estimate the demand for board-certified nuclear medicine physicists in the next 5-10 years,• Identify the critical issues related to supplying an adequate number of physicists who have received the appropriate level of training in nuclear medicine physics, and• Identify approaches that may be considered to facilitate the training of nuclear medicine physicists.As a result, a task force was appointed and chaired by an active member of both organizations that included representation from the AAPM, SNMMI, the American Board of Radiology (ABR), the American Board of Science in Nuclear Medicine (ABSNM), and the Commission for the Accreditation of Medical Physics Educational Programs (CAMPEP). The Task Force first met at the AAPM Annual Meeting in Charlotte in July 2012 and has met regularly face-to-face, online, and by conference calls. This manuscript reports the findings of the Task Force, as well as recommendations to achieve the stated mission.

  6. AAPM/SNMMI Joint Task Force: report on the current state of nuclear medicine physics training.

    PubMed

    Harkness, Beth A; Allison, Jerry D; Clements, Jessica B; Coffey, Charles W; Fahey, Frederic H; Gress, Dustin A; Kinahan, Paul E; Nickoloff, Edward L; Mawlawi, Osama R; MacDougall, Robert D; Pizzuitello, Robert J

    2015-09-01

    The American Association of Physicists in Medicine (AAPM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) recognized the need for a review of the current state of nuclear medicine physics training and the need to explore pathways for improving nuclear medicine physics training opportunities. For these reasons, the two organizations formed a joint AAPM/SNMMI Ad Hoc Task Force on Nuclear Medicine Physics Training. The mission of this task force was to assemble a representative group of stakeholders to: Estimate the demand for board-certified nuclear medicine physicists in the next 5-10 years, Identify the critical issues related to supplying an adequate number of physicists who have received the appropriate level of training in nuclear medicine physics, and Identify approaches that may be considered to facilitate the training of nuclear medicine physicists. As a result, a task force was appointed and chaired by an active member of both organizations that included representation from the AAPM, SNMMI, the American Board of Radiology (ABR), the American Board of Science in Nuclear Medicine (ABSNM), and the Commission for the Accreditation of Medical Physics Educational Programs (CAMPEP). The Task Force first met at the AAPM Annual Meeting in Charlotte in July 2012 and has met regularly face-to-face, online, and by conference calls. This manuscript reports the findings of the Task Force, as well as recommendations to achieve the stated mission. PACS number: 01.40.G.

  7. The Sum of Their Fears: The Relationship Between the Joint Targeting Coordination Board and the Joint Force Commander.

    DTIC Science & Technology

    1994-06-01

    established the Joint Target Group (JTG) on August 2, 1944. The JCS organized the JTG because, "Duplication of effort and lack of integration between the...field.ŗ The JCS tasked the Joint Target Group to provide continuing target analysis and assure a high degree of integration and coordination between...Memorandum, JCS 1020, subject: Joint Target Group , 24 August 1944, USAFHRA No K142.6601-1, 4. 3 Ibid. 2. 9 made it clear that the "Joint Targeting

  8. Software Technology for Adaptable Reliable Systems (STARS) Joint Task Force Report.

    DTIC Science & Technology

    1983-03-15

    34 NCASIFE 4 * ~~SIN 6162 -0618 -ŝ SCCUOUT? LASS8FlCAT@IO0 THIS PASShII . 0 am * SOFTWARE TECHNOLOGY FOR ADAPTABLE, RELIABLE SYSTEMS (STARS) JOINT TASK...Following the workshop, the Task Force concentrated on producing the final set of documents (see Section 4 ! 0 for a complete list). Revisions were...Lafayette, LA. 7(504’ Jack C. Wileden Univ. of Mass. 115 Pelham Road Amherst, MA. 01002 9 4 ° /, * -.. r*• 4 0 DOCUMENTS PRODUCED The following documents are

  9. One Size Does Not Fit All: How Acquisition Fails the Joint Force Commander

    DTIC Science & Technology

    2010-04-02

    acquisition programs, such as the F-35, is worth the risk it presents to the nation by putting all ― eggs in one basket.‖ According to Joint Pub 1...Staff Procurement Backup Book: FY 2010 Budget Estimates, Research, Development, Test and Evaluation (RDT&E), Descriptive Summaries,‖ Vol. 3, May 2009...superiority fighter. This political climate caused the Air Force to recast the aircraft as a multi-role fighter and to scramble to add some air-to-ground

  10. Modeling of muscle forces in humans with and without temporomandibular joint disorders

    PubMed Central

    Iwasaki, LR; Liu, H; Gonzalez, YM; Marx, DB; Nickel, JC

    2015-01-01

    Objectives Subjects with/without temporomandibular joint disorders (TMJD) were tested for differences in muscle forces. Setting and Sample Population School of Dental Medicine, University at Buffalo. Ninety-one subjects were classified in 4 groups based on presence/absence (+/-) of chronic myofascial and/or TMJ pain (P) and bilateral disc displacement (DD). Material & Methods Validated numerical models employed an organizational objective and subjects’ anatomy to calculate masticatory muscle forces during static biting. ANOVA and Holm step-down procedure post-hoc tests assessed group differences. Theoretical geometries, representing the range of subjects’ muscle orientations, were surveyed via numerical models to identify key combinations resulting in high muscle forces. Effect-size (Cohen’s d) and ANOVA/post-hoc tests assessed group differences in key muscle orientations. Results +P-DD subjects had significantly higher muscle forces, especially for lateral pterygoid muscles, compared to the other groups (P<0.01) for bite-forces that were directed posteromedially or posterolaterally on mandibular molars and posteriorly and slightly medially on mandibular incisors. Key muscle orientations for peak lateral pterygoid muscle forces were identified and group comparisons showed mean orientation in +P-DD compared to other diagnostic groups was ≥5° more upright for masseter and ≥3° more posteriorly-directed for temporalis muscles (all Cohen’s d ≥0.8). Conclusion Predicted lateral pterygoid muscle forces were significantly higher in +P-DD compared to other groups for specific biting conditions and were attributable, in part, to differences in masseter and temporalis muscle orientations. PMID:25865546

  11. The senses of force and heaviness at the human elbow joint.

    PubMed

    Brooks, Jack; Allen, Trevor J; Proske, Uwe

    2013-05-01

    The present-day view of the neural basis for the senses of muscle force and heaviness is that they are generated centrally, within the brain, from copies of motor commands. A corollary of the motor discharge generates a sense of effort which underlies these sensations. In recent experiments on force and heaviness sensations using thumb flexor muscles, a rather different explanation has been invoked: Subjects were proposed to rely predominantly on inputs of a peripheral origin, in particular, the signals of muscle spindles. The present experiments have been carried out at the elbow joint to determine whether these new ideas apply more widely. The effects of fatigue of elbow flexor muscles have been studied in force and heaviness matching tasks using three exercise regimes, a sustained maximum voluntary contraction (MVC), a maintained contraction of 35 % MVC, and a maintained contraction of 35 % MVC combined with muscle vibration at 80 Hz. In force-matching experiments, subjects were required to contract both arms and while the reference arm generated the target force under visual control, it was matched by the indicator arm without visual feedback. During the 100 % MVC exercise, force in the exercising reference arm fell rapidly to almost a half of its original value over 90 s while force in the indicator did not fall, leading to a significant overestimation of the reference force. During the 35 % MVC exercise, subjects also overestimated the reference force and this persisted at 5 and 10 min after the exercise. When 35 % MVC was combined with vibration, the amount by which the indicator arm overestimated the reference force was significantly reduced. In heaviness matching experiments, subjects could move their arms through a small range. The reference arm was loaded with a weight, and weights were added or removed from the indicator until heaviness felt the same in the two arms. There was a small, but significant fall in the matching weight used after 100 % MVC

  12. Human force discrimination during active arm motion for force feedback design.

    PubMed

    Feyzabadi, Seyedshams; Straube, Sirko; Folgheraiter, Michele; Kirchner, Elsa Andrea; Kim, Su Kyoung; Albiez, Jan Christian

    2013-01-01

    The goal of this study was to analyze the human ability of external force discrimination while actively moving the arm. With the approach presented here, we give an overview for the whole arm of the just-noticeable differences (JNDs) for controlled movements separately executed for the wrist, elbow, and shoulder joints. The work was originally motivated in the design phase of the actuation system of a wearable exoskeleton, which is used in a teleoperation scenario where force feedback should be provided to the subject. The amount of this force feedback has to be calibrated according to the human force discrimination abilities. In the experiments presented here, 10 subjects performed a series of movements facing an opposing force from a commercial haptic interface. Force changes had to be detected in a two-alternative forced choice task. For each of the three joints tested, perceptual thresholds were measured as absolute thresholds (no reference force) and three JNDs corresponding to three reference forces chosen. For this, we used the outcome of the QUEST procedure after 70 trials. Using these four measurements we computed the Weber fraction. Our results demonstrate that different Weber fractions can be measured with respect to the joint. These were 0.11, 0.13, and 0.08 for wrist, elbow, and shoulder, respectively. It is discussed that force perception may be affected by the number of muscles involved and the reproducibility of the movement itself. The minimum perceivable force, on average, was 0.04 N for all three joints.

  13. Injury patterns to other body regions and load vectors in nearside impact occupants with and without shoulder injuries

    PubMed Central

    Yoganandan, Narayan; Stadter, Gregory W.; Halloway, Dale E.; Pintar, Frank A.

    2013-01-01

    CIREN and NASS-CDS databases were used to analyze nearside impact injuries. Front seat occupants with and without shoulder injuries were examined on an individual basis in both databases. All vehicles were from model year 2000 or newer. Variables such as the type of collision, change in velocity, principal direction force, demographics, injuries scored by the MAIS and ISS metrics, and injuries to the head, thorax, abdomen and pelvis were included. Shoulder injuries included fractures to the humerus, scapula and clavicle, and associated joint traumas. The median changes in velocities for occupants with and without shoulder injuries were 36 and 32 km/h in CIREN and 29 and 32 km/h in NASS databases. Approximately two-thirds of all cases occurred below 40 km/h. In both databases, the clavicle, scapula and humerus fractures, and AC joint dislocations were found, and the scapula fracture was associated with the clavicle, AC joint, acromion and humerus injuries in few occupants. The clavicle fracture was associated with AC joint and humerus injuries only in the NASS database. Thorax, abdomen and pelvic injuries and skull fractures increased with the presence of shoulder injuries in both databases, albeit not at the same rate. Anterior oblique loading was more frequent than pure lateral loading in both databases suggesting the importance of the oblique vector in side impact trauma. These findings underscore a need for detailed examinations of shoulder load-sharing using biomechanical studies to better understand its role in side impact traumas, shoulder biofidelity and injury assessments in dummies. PMID:24406953

  14. The Role of the Sensorimotor System in the Athletic Shoulder

    PubMed Central

    Myers, Joseph B.; Lephart, Scott M.

    2000-01-01

    Objective: To discuss the role of the sensorimotor system as it relates to functional stability, joint injury, and muscle fatigue of the athletic shoulder and to provide clinicians with the necessary tools for restoring functional stability to the athletic shoulder after injury. Data Sources: We searched MEDLINE, SPORT Discus, and CINAHL from 1965 through 1999 using the key words “proprioception,” “neuromuscular control,” “shoulder rehabilitation,” and “shoulder stability.” Data Synthesis: Shoulder functional stability results from an interaction between static and dynamic stabilizers at the shoulder. This interaction is mediated by the sensorimotor system. After joint injury or fatigue, proprioceptive deficits have been demonstrated, and neuromuscular control has been altered. To restore stability after injury, deficits in both mechanical stability and proprioception and neuromuscular control must be addressed. A functional rehabilitation program addressing awareness of proprioception, restoration of dynamic stability, facilitation of preparatory and reactive muscle activation, and implementation of functional activities is vital for returning an athlete to competition. Conclusions/Recommendations: After capsuloligamentous injury to the shoulder joint, decreased proprioceptive input to the central nervous system results in decreased neuromuscular control. The compounding effects of mechanical instability and neuromuscular deficits create an unstable shoulder joint. Clinicians should not only address the mechanical instability that results from joint injury but also implement both traditional and functional rehabilitation to return an athlete to competition. ImagesFigure 2.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8. PMID:16558648

  15. Muscle optimization techniques impact the magnitude of calculated hip joint contact forces.

    PubMed

    Wesseling, Mariska; Derikx, Loes C; de Groote, Friedl; Bartels, Ward; Meyer, Christophe; Verdonschot, Nico; Jonkers, Ilse

    2015-03-01

    In musculoskeletal modelling, several optimization techniques are used to calculate muscle forces, which strongly influence resultant hip contact forces (HCF). The goal of this study was to calculate muscle forces using four different optimization techniques, i.e., two different static optimization techniques, computed muscle control (CMC) and the physiological inverse approach (PIA). We investigated their subsequent effects on HCFs during gait and sit to stand and found that at the first peak in gait at 15-20% of the gait cycle, CMC calculated the highest HCFs (median 3.9 times peak GRF (pGRF)). When comparing calculated HCFs to experimental HCFs reported in literature, the former were up to 238% larger. Both static optimization techniques produced lower HCFs (median 3.0 and 3.1 pGRF), while PIA included muscle dynamics without an excessive increase in HCF (median 3.2 pGRF). The increased HCFs in CMC were potentially caused by higher muscle forces resulting from co-contraction of agonists and antagonists around the hip. Alternatively, these higher HCFs may be caused by the slightly poorer tracking of the net joint moment by the muscle moments calculated by CMC. We conclude that the use of different optimization techniques affects calculated HCFs, and static optimization approached experimental values best.

  16. Joint strength measurements of individual fiber-fiber bonds: An atomic force microscopy based method

    NASA Astrophysics Data System (ADS)

    Schmied, Franz J.; Teichert, Christian; Kappel, Lisbeth; Hirn, Ulrich; Schennach, Robert

    2012-07-01

    We are introducing a method to measure tensile strength of individual fiber-fiber bonds within a breaking force range of 0.01 mN-1 mN as well as the energy consumed during breaking. Until now, such a method was not available. Using a conventional atomic force microscope and a specifically designed sample holder, the desired force and the breaking behavior can be analyzed by two different approaches. First, dynamic loading can be applied, where force-versus-distance curves are employed to determine the proportions of elastic energy and energy dissipated in the bond. Second, static loading is utilized to study viscoelastic behavior and calculate viscoelastic energy contributions. To demonstrate the capability of the proposed method, we are presenting results for breaking strength of kraft pulp fiber-fiber bonds in tensile opening mode. The procedure is by no means restricted to cellulose fibers, it has the potential to quantify joint strength of micrometer-sized fibers in general.

  17. Shoulder Kinematics and Spatial Pattern of Trapezius Electromyographic Activity in Real and Virtual Environments

    PubMed Central

    Samani, Afshin; Pontonnier, Charles; Dumont, Georges; Madeleine, Pascal

    2015-01-01

    The design of an industrial workstation tends to include ergonomic assessment steps based on a digital mock-up and a virtual reality setup. Lack of interaction and system fidelity is often reported as a main issue in such virtual reality applications. This limitation is a crucial issue as thorough ergonomic analysis is required for an investigation of the biomechanics. In the current study, we investigated the biomechanical responses of the shoulder joint in a simulated assembly task for comparison with the biomechanical responses in virtual environments. Sixteen male healthy novice subjects performed the task on three different platforms: real (RE), virtual (VE), and virtual environment with force feedback (VEF) with low and high precision demands. The subjects repeated the task 12 times (i.e., 12 cycles). High density electromyography from the upper trapezius and rotation angles of the shoulder joint were recorded and split into the cycles. The angular trajectories and velocity profiles of the shoulder joint angles over a cycle were computed in 3D. The inter-subject similarity in terms of normalized mutual information on kinematics and electromyography was investigated. Compared with RE the task in VE and VEF was characterized by lower kinematic maxima. The inter-subject similarity in RE compared with intra-subject similarity across the platforms was lower in terms of movement trajectories and greater in terms of trapezius muscle activation. The precision demand resulted in lower inter- and intra-subject similarity across platforms. The proposed approach identifies biomechanical differences in the shoulder joint in both VE and VEF compared with the RE platform, but these differences are less marked in VE mostly due to technical limitations of co-localizing the force feedback system in the VEF platform. PMID:25768123

  18. Shoulder kinematics and spatial pattern of trapezius electromyographic activity in real and virtual environments.

    PubMed

    Samani, Afshin; Pontonnier, Charles; Dumont, Georges; Madeleine, Pascal

    2015-01-01

    The design of an industrial workstation tends to include ergonomic assessment steps based on a digital mock-up and a virtual reality setup. Lack of interaction and system fidelity is often reported as a main issue in such virtual reality applications. This limitation is a crucial issue as thorough ergonomic analysis is required for an investigation of the biomechanics. In the current study, we investigated the biomechanical responses of the shoulder joint in a simulated assembly task for comparison with the biomechanical responses in virtual environments. Sixteen male healthy novice subjects performed the task on three different platforms: real (RE), virtual (VE), and virtual environment with force feedback (VEF) with low and high precision demands. The subjects repeated the task 12 times (i.e., 12 cycles). High density electromyography from the upper trapezius and rotation angles of the shoulder joint were recorded and split into the cycles. The angular trajectories and velocity profiles of the shoulder joint angles over a cycle were computed in 3D. The inter-subject similarity in terms of normalized mutual information on kinematics and electromyography was investigated. Compared with RE the task in VE and VEF was characterized by lower kinematic maxima. The inter-subject similarity in RE compared with intra-subject similarity across the platforms was lower in terms of movement trajectories and greater in terms of trapezius muscle activation. The precision demand resulted in lower inter- and intra-subject similarity across platforms. The proposed approach identifies biomechanical differences in the shoulder joint in both VE and VEF compared with the RE platform, but these differences are less marked in VE mostly due to technical limitations of co-localizing the force feedback system in the VEF platform.

  19. Shoulder biomechanics and muscle plasticity: implications in spinal cord injury.

    PubMed

    Lee, Thay Q; McMahon, Patrick J

    2002-10-01

    After spinal cord injury, excessive burden falls on the upper extremity, especially the shoulder. Overall, 51% of persons with spinal cord injury have shoulder problems. Common shoulder problems in persons with spinal cord injury begin with muscle imbalance that can lead to glenohumeral instability, impingement disease, rotator cuff tears, and subsequent degenerative joint disease. These problems can be attributed to the functional demands placed on the shoulder that are specific to patients with spinal cord injury, including overhead activities, wheelchair use, and transfers. Despite preventive exercises, shoulder problems in persons with spinal cord injury remain a significant problem, causing pain and functional limitations. The biomechanics of the shoulder for persons with spinal cord injury resulting from changes in muscle plasticity will be elucidated. Specifically, the effects of scapular protraction that can result from muscle imbalance, the age-dependent properties of the anterior band of the inferior glenohumeral ligament, and the influence of the dynamic restraints around the shoulder will be addressed.

  20. Validation of Shoulder Response of Human Body Finite-Element Model (GHBMC) Under Whole Body Lateral Impact Condition.

    PubMed

    Park, Gwansik; Kim, Taewung; Panzer, Matthew B; Crandall, Jeff R

    2016-08-01

    In previous shoulder impact studies, the 50th-percentile male GHBMC human body finite-element model was shown to have good biofidelity regarding impact force, but under-predicted shoulder deflection by 80% compared to those observed in the experiment. The goal of this study was to validate the response of the GHBMC M50 model by focusing on three-dimensional shoulder kinematics under a whole-body lateral impact condition. Five modifications, focused on material properties and modeling techniques, were introduced into the model and a supplementary sensitivity analysis was done to determine the influence of each modification to the biomechanical response of the body. The modified model predicted substantially improved shoulder response and peak shoulder deflection within 10% of the observed experimental data, and showed good correlation in the scapula kinematics on sagittal and transverse planes. The improvement in the biofidelity of the shoulder region was mainly due to the modifications of material properties of muscle, the acromioclavicular joint, and the attachment region between the pectoralis major and ribs. Predictions of rib fracture and chest deflection were also improved because of these modifications.

  1. Arthroscopic stabilization procedures for recurrent anterior shoulder instability.

    PubMed

    Yahiro, M A; Matthews, L S

    1989-11-01

    Anterior shoulder instability is a common and functionally disabling problem in young athletes. The goal in treatment of this condition is a stable, yet mobile, joint. Current methods now being utilized in the arthroscopic stabilization of the anterior shoulder include staple capsulorrhaphy, removable rivet capsulorrhaphy, cannulated screw fixation, and the transglenoid suture technique. These techniques and the clinical experience with each are reviewed, with an emphasis on providing stability, improving function, and allowing earlier rehabilitation in the unstable shoulder of the athlete.

  2. 9. Painful shoulder complaints.

    PubMed

    Huygen, Frank; Patijn, Jacob; Rohof, Olav; Lataster, Arno; Mekhail, Nagy; van Kleef, Maarten; Van Zundert, Jan

    2010-01-01

    Painful shoulder complaints have a high incidence and prevalence. The etiology is not always clear. Clinical history and the active and passive motion examination of the shoulder are the cornerstones of the diagnostic process. Three shoulder tests are important for the examination of shoulder complaints: shoulder abduction, shoulder external rotation, and horizontal shoulder adduction. These tests can guide the examiner to the correct diagnosis. Based on this diagnosis, in most cases, primarily a conservative treatment with nonsteroidal anti-inflammatory drugs possibly in combination with manual and/or exercise therapy can be started. When conservative treatment fails, injection with local anesthetics and corticosteroids can be considered. In the case of frozen shoulder, a continuous cervical epidural infusion of local anesthetic and small doses of opioids or a pulsed radiofrequency treatment of the nervus suprascapularis can be considered.

  3. Shoulder Injuries and Disorders

    MedlinePlus

    ... injured. Common problems include Sprains and strains Dislocations Separations Tendinitis Bursitis Torn rotator cuffs Frozen shoulder Fractures Arthritis Health care providers diagnose shoulder problems by using your medical history, a physical exam, and imaging tests. Often, the first treatment ...

  4. Shoulder surgery - discharge

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000179.htm Shoulder surgery - discharge To use the sharing features on this page, please enable JavaScript. You had shoulder surgery to repair the tissues inside or around ...

  5. Hump behind the shoulders

    MedlinePlus

    ... gov/ency/article/003112.htm Hump behind the shoulders (Dorsocervical fat pad) To use the sharing features ... page, please enable JavaScript. A hump behind the shoulders is an area of fat accumulation on the ...

  6. Inflamed shoulder tendons (image)

    MedlinePlus

    Tearing and inflammation of the tendons of the shoulder muscles can occur in sports which require the ... pitching, swimming, and lifting weights. Most often the shoulder will heal if a break is taken from ...

  7. Effect of elbow joint angle on force-EMG relationships in human elbow flexor and extensor muscles.

    PubMed

    Doheny, Emer P; Lowery, Madeleine M; Fitzpatrick, David P; O'Malley, Mark J

    2008-10-01

    The purpose of this study was to examine the effect of joint angle on the relationship between force and electromyogram (EMG) amplitude and median frequency, in the biceps, brachioradialis and triceps muscles. Surface EMG were measured at eight elbow angles, during isometric flexion and extension at force levels from 10% to 100% of maximum voluntary contraction (MVC). Joint angle had a significant effect on MVC force, but not on MVC EMG amplitude in all of the muscles examined. The median frequency of the biceps and triceps EMG decreased with increasing muscle length, possibly due to relative changes in electrode position or a decrease in muscle fibre diameter. The relationship between EMG amplitude and force, normalised with respect to its maximum force at each angle, did not vary with joint angle in the biceps or brachioradialis muscles over all angles, or in the triceps between 45 degrees and 120 degrees of flexion. These results suggest that the neural excitation level to each muscle is determined by the required percentage of available force rather than the absolute force required. It is, therefore, recommended that when using surface EMG to estimate muscle excitation, force should be normalised with respect to its maximum value at each angle.

  8. Trunk and shoulder kinematic and kinetic and electromyographic adaptations to slope increase during motorized treadmill propulsion among manual wheelchair users with a spinal cord injury.

    PubMed

    Gagnon, Dany; Babineau, Annie-Claude; Champagne, Audrey; Desroches, Guillaume; Aissaoui, Rachid

    2015-01-01

    The main objective was to quantify the effects of five different slopes on trunk and shoulder kinematics as well as shoulder kinetic and muscular demands during manual wheelchair (MWC) propulsion on a motorized treadmill. Eighteen participants with spinal cord injury propelled their MWC at a self-selected constant speed on a motorized treadmill set at different slopes (0°, 2.7°, 3.6°, 4.8°, and 7.1°). Trunk and upper limb movements were recorded with a motion analysis system. Net shoulder joint moments were computed with the forces applied to the handrims measured with an instrumented wheel. To quantify muscular demand, the electromyographic activity (EMG) of the pectoralis major (clavicular and sternal portions) and deltoid (anterior and posterior fibers) was recorded during the experimental tasks and normalized against maximum EMG values obtained during static contractions. Overall, forward trunk flexion and shoulder flexion increased as the slope became steeper, whereas shoulder flexion, adduction, and internal rotation moments along with the muscular demand also increased as the slope became steeper. The results confirm that forward trunk flexion and shoulder flexion movement amplitudes, along with shoulder mechanical and muscular demands, generally increase when the slope of the treadmill increases despite some similarities between the 2.7° to 3.6° and 3.6° to 4.8° slope increments.

  9. Joint Task Force on Undergraduate Physics Programs (J-TUPP): Overview and Major Findings

    NASA Astrophysics Data System (ADS)

    Heron, Paula

    2016-03-01

    The Joint Task Force on Undergraduate Physics Programs (JTUPP) was formed in response to growing awareness in the physics community that physics majors pursue a wide range of careers after graduation, with very few ending up in academia. The task force is charged with identifying the skills and knowledge that undergraduate physics degree holders should possess to be well prepared for a diverse set of careers, and providing guidance for physicists considering revising the undergraduate curriculum to improve the education of a diverse student population. Task force members represent large and small universities, professional societies, and industry, and have expertise in a broad range of areas including entrepreneurship, physics education research and systemic change in education. We reviewed employment data, surveys of employers, and reports generated by other disciplines. We also met with physicists in selected industries to get their views on the strengths and weaknesses of physics graduates, commissioned a series of interviews with recent physics graduates employed in the private sector, and identified exemplary programs that ensure that all of their students are well prepared to pursue a wide range of career paths. The findings and recommendations will be summarized.

  10. Pharmacokinetic interaction after joint administration of zinc and imipramine in forced swim test in mice.

    PubMed

    Wyska, Elzbieta; Szymura-Oleksiak, Joanna; Opoka, Włodzimierz; Baś, Bogusław; Niewiara, Ewa; Pomierny, Lucyna; Dybała, Małgorzata; Nowak, Gabriel

    2004-01-01

    Recent preclinical and clinical data indicate beneficial role of zinc in the antidepressant treatment. To evaluate the mechanism of interaction between zinc and antidepressants, in the present study we examined the brain zinc, imipramine and desipramine concentrations in mice treated with combinations of zinc and imipramine and subjected to the forced swim test. We have chosen doses of zinc (10 mg/kg) and imipramine (15 mg/kg) which we have previously found to be ineffective in the forced swim test when given alone. However, when administered jointly, a significant reduction in the immobility time in this test was demonstrated. In the present study, we demonstrated a significant ca. 60% reduction in the brain desipramine and non-significant reduction (ca. 40%) in brain imipramine concentrations in the group of animals treated with zinc plus imipramine compared with animals treated with imipramine alone. The brain zinc concentration in the zinc plus imipramine group was reduced when compared with the group treated with zinc or imipramine alone. Since there was no increase in brain imipramine/desipramine or zinc brain concentration after combined zinc and imipramine treatment, the data suggest that pharmacodynamic rather than pharmacokinetic interaction between zinc and imipramine is responsible for behavioral effect in the forced swim test.

  11. Evolution of the reverse total shoulder prosthesis.

    PubMed

    Jazayeri, Reza; Kwon, Young W

    2011-01-01

    Over the last decade, reverse total shoulder arthroplasty has gained significant popularity due to its ability to address difficult reconstructive shoulder problems that could not be adequately treated in the past. The concept of the reverse shoulder prosthesis was introduced in the 1970s, but the initial attempts were associated with high complication and implant failure rates. The pioneering work of Paul Grammont (shifting the center of rotation medially and distally) and the development of the DELTA prosthesis have been fundamental to all subsequent reverse shoulder arthroplasty systems. These semiconstrained prostheses utilize the deltoid to improve function and stability of the shoulder joint by coupling a convex glenoid with a concave humeral component. Modern generations of reverse shoulder prosthesis continue to evolve on the fundamentals of Grammont. Though results of these new prosthesis demonstrate promising outcomes, many controversies and challenges continue to be refined. An historical review of the evolution of reverse shoulder arthroplasty is presented, as well as the currently expanding indications for its application.

  12. Prediction of hip joint load and translation using musculoskeletal modelling with force-dependent kinematics and experimental validation.

    PubMed

    Zhang, Xuan; Chen, Zhenxian; Wang, Ling; Yang, Wenjian; Li, Dichen; Jin, Zhongmin

    2015-07-01

    Musculoskeletal lower limb models are widely used to predict the resultant contact force in the hip joint as a non-invasive alternative to instrumented implants. Previous musculoskeletal models based on rigid body assumptions treated the hip joint as an ideal sphere with only three rotational degrees of freedom. An musculoskeletal model that considered force-dependent kinematics with three additional translational degrees of freedom was developed and validated in this study by comparing it with a previous experimental measurement. A 32-mm femoral head against a polyethylene cup was considered in the musculoskeletal model for calculating the contact forces. The changes in the main modelling parameters were found to have little influence on the hip joint forces (relative deviation of peak value < 10 BW%, mean trial deviation < 20 BW%). The centre of the hip joint translation was more sensitive to the changes in the main modelling parameters, especially muscle recruitment type (relative deviation of peak value < 20%, mean trial deviation < 0.02 mm). The predicted hip contact forces showed consistent profiles, compared with the experimental measurements, except in the lateral-medial direction. The ratio-average analysis, based on the Bland-Altman's plots, showed better limits of agreement in climbing stairs (mean limits of agreement: -2.0 to 6.3 in walking, mean limits of agreement: -0.5 to 3.1 in climbing stairs). Better agreement of the predicted hip contact forces was also found during the stance phase. The force-dependent kinematics approach underestimated the maximum hip contact force by a mean value of 6.68 ± 1.75% BW compared with the experimental measurements. The predicted maximum translations of the hip joint centres were 0.125 ± 0.03 mm in level walking and 0.123 ± 0.005 mm in climbing stairs.

  13. Anatomy and Selected Biomechanical Aspects of the Shoulder.

    ERIC Educational Resources Information Center

    Keene, James S.

    This paper focuses on the anatomy and functions of the shoulder that are relevant to the evaluation and treatment of athletic injuries. A discussion is presented on the four basic components of the shoulder mechanism: (1) super structure--bony components; (2) moving parts--joints involved; (3) motor power--musculature; and (4) communications…

  14. The acute effects of static stretching on peak force, peak rate of force development and muscle activity during single- and multiple-joint actions in older women.

    PubMed

    Gonçalves, Raquel; Gurjão, André Luiz Demantova; Jambassi Filho, José Claudio; Farinatti, Paulo De Tarso Veras; Gobbi, Lilian Teresa Bucken; Gobbi, Sebastião

    2013-01-01

    The present study investigated the acute effects of static stretching on peak force, peak rate of force development and integrated electromyography (iEMG) in 27 older women (65 ± 4 years; 69 ± 9 kg; 157 ± 1 cm; 28 ± 4 kg · m(-2)). The participants were tested during two exercises (leg press and knee extension) after two conditions: stretching and control. The data were collected on four days (counterbalanced with a 24-hour rest period). In the stretching condition, the quadriceps muscle was stretched (knee flexion) for three sets of 30 s with 30 s rest intervals. No significant difference was detected for peak force and peak rate of force development during the single- and multiple-joint exercises, regardless of the following interactions: condition (stretching and control) vs. time (pre x post x 10 x 20 x 30 minutes post; P > 0.05) and exercise vs. time (P > 0.05). Additionally, no significant interaction was found for the iEMG activity (condition vs. time; P > 0.05) in the single- and multiple-joint exercises. In conclusion, a small amount of stretching of an agonist muscle (quadriceps) did not affect the peak force, peak rate of force development and EMG activity in older women during single- and multiple-joint exercises.

  15. Shoulder Problems in Athletes.

    ERIC Educational Resources Information Center

    Clancy, William G., Jr.

    A description is given of typical sport-related injuries to the shoulder area. These include: (1) brachial plexus injuries; (2) peripheral nerve injuries about the shoulder; (3) acromioclavicular injuries; (4) sternoclavicular injuries; (5) shoulder dislocations; (6) recurrent traumatic subluxation/dislocations; and (7) overuse injuries.…

  16. Acromioclavicular Joint Separations

    DTIC Science & Technology

    2013-01-01

    non-surgical measures, high-grade inju- ries frequently warrant surgical intervention to minimize pain and maximize shoulder function. Factors such as...sports [1–3]. While most injuries can be managed non-operatively, high-grade separations may result in per- sistent pain or functional decline and...joint pathology (cross arm adduction and loading of the AC joint) can be helpful to localize shoulder pain to the AC joint. These tests are especial- ly

  17. The effect of toe marker placement error on joint kinematics and muscle forces using OpenSim gait simulation.

    PubMed

    Xu, Hang; Merryweather, Andrew; Bloswick, Donald; Mao, Qi; Wang, Tong

    2015-01-01

    Marker placement can be a significant source of error in biomechanical studies of human movement. The toe marker placement error is amplified by footwear since the toe marker placement on the shoe only relies on an approximation of underlying anatomical landmarks. Three total knee replacement subjects were recruited and three self-speed gait trials per subject were collected. The height variation between toe and heel markers of four types of footwear was evaluated from the results of joint kinematics and muscle forces using OpenSim. The reference condition was considered as the same vertical height of toe and heel markers. The results showed that the residual variances for joint kinematics had an approximately linear relationship with toe marker placement error for lower limb joints. Ankle dorsiflexion/plantarflexion is most sensitive to toe marker placement error. The influence of toe marker placement error is generally larger for hip flexion/extension and rotation than hip abduction/adduction and knee flexion/extension. The muscle forces responded to the residual variance of joint kinematics to various degrees based on the muscle function for specific joint kinematics. This study demonstrates the importance of evaluating marker error for joint kinematics and muscle forces when explaining relative clinical gait analysis and treatment intervention.

  18. [The effect of the motion of forefoot joint at the force exerted upon the floor during walking exercise].

    PubMed

    Maeda, A; Nishizono, H; Ebashi, H; Shibayama, H

    1993-11-01

    In walking exercise the human body is exposed to external forces. Some of them are produced by constraints such as surface, shoes or opponent. In kick action of walking, the ground reaction force (GRF) is the most important external force. The magnitude of the GRF, its direction, and point of application have an influence on the load on the human body. The purpose of this study is to clarify the role of forefoot joint (artt. metatarsophalangeae) at the force exerted upon the floor during kick action of walking. The device used in this study to analyze the GRF and its three components consists of Kistler's force platform. Output from force transducer was collected online with a TEAC data recorder and MEM-4101 minicomputer. The impact force measurements were taken from the anterior-posterior force time curves at the take-off for 1 subject walking 10 trials at 2 m/sec with 2 different pairs of shoes (Shoes 1: thin sole of 4mm, and Shoes 2: thick sole of 40mm) and without shoes. High speed (200f/sec) cinematography was also used to analyze the angular displacement of forefoot joint at the take-off of walking exercise. The force acting at the forefoot joint may produce the anterior-posterior force of the GRF which is defined as the propelling power acting on the human body during walking exercise. The result showed that the impact force peak occurred 40-60 msec before take-off and the propelling part of kick action accounted for only about 6% of the external force.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Effect of ACL graft material on joint forces during a simulated in vivo motion in the porcine knee: examining force during the initial cycles.

    PubMed

    Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

    2014-11-01

    This study compared three-dimensional forces in knees containing anterior cruciate ligament (ACL) graft materials versus the native porcine ACL. A six-degree-of-freedom (DOF) robot simulated gait while recording the joint forces and moments. Knees were subjected to 10 cycles of simulated gait in intact, ACL-deficient, and ACL-reconstructed knee states to examine time zero biomechanical performance. Reconstruction was performed using bone-patellar tendon-bone allograft (BPTB), reconstructive porcine tissue matrix (RTM), and an RTM-polymer hybrid (Hybrid). Forces and moments were examined about anatomic DOFs throughout the gait cycle and at three key points during gait: heel strike (HS), mid stance (MS), toe off (TO). Compared to native ACL, each graft restored antero-posterior (A-P) forces throughout gait. However, all failed to mimic normal joint forces in other DOFs. For example, each reconstructed knee showed greater compressive forces at HS and TO compared to the native ACL knee. Overall, the Hybrid graft restored more of the native ACL forces following reconstruction than did BPTB, while RTM grafts were the least successful. If early onset osteoarthritis is in part caused by altered knee kinematics, then understanding how reconstruction materials restore critical force generation during gait is an essential step in improving a patient's long-term prognosis.

  20. Developing a musculoskeletal model of the primate skull: predicting muscle activations, bite force, and joint reaction forces using multibody dynamics analysis and advanced optimisation methods.

    PubMed

    Shi, Junfen; Curtis, Neil; Fitton, Laura C; O'Higgins, Paul; Fagan, Michael J

    2012-10-07

    An accurate, dynamic, functional model of the skull that can be used to predict muscle forces, bite forces, and joint reaction forces would have many uses across a broad range of disciplines. One major issue however with musculoskeletal analyses is that of muscle activation pattern indeterminacy. A very large number of possible muscle force combinations will satisfy a particular functional task. This makes predicting physiological muscle recruitment patterns difficult. Here we describe in detail the process of development of a complex multibody computer model of a primate skull (Macaca fascicularis), that aims to predict muscle recruitment patterns during biting. Using optimisation criteria based on minimisation of muscle stress we predict working to balancing side muscle force ratios, peak bite forces, and joint reaction forces during unilateral biting. Validation of such models is problematic; however we have shown comparable working to balancing muscle activity and TMJ reaction ratios during biting to those observed in vivo and that peak predicted bite forces compare well to published experimental data. To our knowledge the complexity of the musculoskeletal model is greater than any previously reported for a primate. This complexity, when compared to more simple representations provides more nuanced insights into the functioning of masticatory muscles. Thus, we have shown muscle activity to vary throughout individual muscle groups, which enables them to function optimally during specific masticatory tasks. This model will be utilised in future studies into the functioning of the masticatory apparatus.

  1. Bite force in the extant coelacanth Latimeria: the role of the intracranial joint and the basicranial muscle.

    PubMed

    Dutel, Hugo; Herbin, Marc; Clément, Gaël; Herrel, Anthony

    2015-05-04

    The terrestrialization process involved dramatic changes in the cranial anatomy of vertebrates. The braincase, which was initially divided into two portions by the intracranial joint in sarcopterygian fishes, became consolidated into a single unit in tetrapods and lungfishes [1-3]. The coelacanth Latimeria is the only extant vertebrate that retains an intracranial joint, which is associated with a unique paired muscle: the basicranial muscle. The intracranial joint has long been thought to be involved in suction feeding by allowing an extensive elevation of the anterior portion of the skull, followed by its rapid depression driven by the basicranial muscle [4-7]. However, we recently challenged this hypothesis [8, 9], and the role of the basicranial muscle with respect to the intracranial joint thus remains unclear. Using 3D biomechanical modeling, we show here that the basicranial muscle and the intracranial joint are involved in biting force generation. By flexing the anterior portion of the skull at the level of the intracranial joint, the basicranial muscle increases the overall bite force. This likely allows Latimeria to feed on a broad range of preys [10, 11] and coelacanths to colonize a wide range of environments during their evolution [4]. The variation in the morphology of the intracranial joint observed in Devonian lobe-finned fishes would have impacted to various degrees their biting performance and might have permitted feeding specializations despite the stability in their lower jaw morphology [12]. VIDEO ABSTRACT.

  2. Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity.

    PubMed

    DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor

    2016-03-01

    A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412 N or 34% of initial body weight reduced maximum knee compressive force by 824 N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392 N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated.

  3. Soldier-relevant body borne loads increase knee joint contact force during a run-to-stop maneuver.

    PubMed

    Ramsay, John W; Hancock, Clifford L; O'Donovan, Meghan P; Brown, Tyler N

    2016-12-08

    The purpose of this study was to understand the effects of load carriage on human performance, specifically during a run-to-stop (RTS) task. Using OpenSim analysis tools, knee joint contact force, grounds reaction force, leg stiffness and lower extremity joint angles and moments were determined for nine male military personnel performing a RTS under three load configurations (light, ~6kg, medium, ~20kg, and heavy, ~40kg). Subject-based means for each biomechanical variable were submitted to repeated measures ANOVA to test the effects of load. During the RTS, body borne load significantly increased peak knee joint contact force by 1.2 BW (p<0.001) and peak vertical (p<0.001) and anterior-posterior (p=0.002) ground reaction forces by 0.6 BW and 0.3 BW, respectively. Body borne load also had a significant effect on hip (p=0.026) posture with the medium load and knee (p=0.046) posture with the heavy load. With the heavy load, participants exhibited a substantial, albeit non-significant increase in leg stiffness (p=0.073 and d=0.615). Increases in joint contact force exhibited during the RTS were primarily due to greater GRFs that impact the soldier with each incremental addition of body borne load. The stiff leg, extended knee and large braking force the soldiers exhibited with the heavy load suggests their injury risk may be greatest with that specific load configuration. Further work is needed to determine if the biomechanical profile exhibited with the heavy load configuration translates to unsafe shear forces at the knee joint and consequently, a higher likelihood of injury.

  4. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

    PubMed Central

    Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

    2016-01-01

    Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications. PMID:27529244

  5. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor.

    PubMed

    Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

    2016-08-11

    Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  6. Dominant vs. non-dominant shoulder morphology in volleyball players and associations with shoulder pain and spike speed.

    PubMed

    Challoumas, Dimitrios; Artemiou, Andreas; Dimitrakakis, Georgios

    2017-01-01

    The aims of our study were to compare the dominant (DOM) and non-dominant (NDOM) shoulders of high-level volleyball athletes and identify possible associations of shoulder adaptations with spike speed (SS) and shoulder pathology. A total of 22 male volleyball players from two teams participating in the first division of the Cypriot championship underwent clinical shoulder tests and simple measurements around their shoulder girdle joints bilaterally. SS was measured with the use of a sports speed radar. Compared with the NDOM side, the DOM scapula was more lateralised, the DOM dorsal capsule demonstrated greater laxity, the DOM dorsal muscles stretching ability was compromised, and the DOM pectoralis muscle was more lengthened. Players with present or past DOM shoulder pain demonstrated greater laxity in their DOM dorsal capsule, tightening of their DOM inferior capsule, and lower SS compared with those without shoulder pain. Dorsal capsule measurements bilaterally were significant predictors of SS. None of the shoulder measurements was associated with team roles or infraspinatus atrophy, while scapular lateralisation was more pronounced with increasing years of experience, and scapular antetilting was greater with increasing age. Adaptations of the DOM shoulder may be linked to pathology and performance. We describe simple shoulder measurements that may have the potential to predict chronic shoulder injury and become part of injury prevention programmes. Detailed biomechanical and large prospective studies are warranted to assess the validity of our findings and reach more definitive conclusions.

  7. Bone remodelling analysis of the humerus after a shoulder arthroplasty.

    PubMed

    Quental, Carlos; Folgado, João; Fernandes, Paulo R; Monteiro, Jacinto

    2012-10-01

    The shoulder arthroplasty has become an efficient treatment for some pathologies. However there are complications that can compromise its success. Among them, the stress shielding effect on the humerus has been reported as a possible cause of failure. The objective of this work was to investigate the bone remodelling in the humerus after a shoulder arthroplasty. For this purpose, computational models were developed to analyse the stress shielding contribution to the humeral component failure of shoulder arthroplasties, with a cemented and an uncemented prosthesis. A computational remodelling model was used to characterize the bone apparent density at each site of the humerus. The density distribution was obtained by the solution of a problem that takes into account both structural stiffness and the metabolic cost of bone maintenance. Bone was subjected to 6 load cases that include the glenohumeral reaction force and the action of 10 muscles. In the implanted models, different interface conditions were tested for the bone-implant and the cement-implant interfaces. Moreover, a pathological case defined by a poorer quality of bone was considered. In the healthy situation, the models that better model in vivo conditions showed no significant changes in bone mass. However, the results for the pathological case showed some bone resorption which supports the importance given to the quality of bone in the success of the joint replacement. Bearing in mind the conditions addressed, the results lead to conclude that the stress shielding is not a key factor for the humeral component failure of shoulder arthroplasties in a healthy situation though several issues, including muscle function and bone quality, may heighten its effect.

  8. Computational analysis of polyethylene wear in anatomical and reverse shoulder prostheses.

    PubMed

    Quental, C; Folgado, J; Fernandes, P R; Monteiro, J

    2015-02-01

    The wear of ultra-high molecular weight polyethylene, UHMWPE, components has been associated with the failure of joint prostheses in the hip, knee, and shoulder. Considering that in vitro experiments are generally too expensive and time-consuming, computational models are an attractive alternative to study the wear behavior of UHMWPE components. The objective of the present study was to develop a computational wear model to evaluate the wear resistance of anatomical and reverse shoulder prostheses. The effects of the wear law and the updating of the UHMWPE surface on the prediction of wear were also considered. Apart from Archard's law, a new wear law, so-called second generation law, which includes the concept of cross-shear and a pressure-independent wear factor, was considered. The wear analyses were performed considering three shoulder joint motions. The muscle and joint reaction forces applied were estimated by an inverse biomechanical model of the upper limb. The results show that abrasive wear is as important for the reverse components as it is for the anatomical. Nevertheless, the volumetric wears estimated over 1 year are within the range considered clinically desirable to reduce the risk of osteolysis. For the anatomical components, the predictions from Archard's law compare better, than those of the second generation law, to the experimental and clinical data available in the literature. Yet, the opposite result is obtained for the reverse components. From the numerical point of view, an updating procedure for the UHMWPE surface is mandatory to improve the numerical predictions.

  9. Shoulder injuries in archery.

    PubMed

    Mann, D L; Littke, N

    1989-06-01

    Twenty-one elite-calibre archers (M = 12, F = 9) were investigated concerning all past and present archery-related shoulder injuries, using a questionnaire and physical examination. The questionnaire revealed that 11 of 21 archers had complained of significant shoulder injuries either currently or during their careers. While 9/12 men never had shoulder problems during an average of 13.5 years, only 4/9 women escaped injury during a mean 10.9 year competitive career. Deficits in training programs were noted, including lack of training and non-specific exercises. Clinical examination demonstrated shoulder asymmetry and decreased flexibility in the drawing arm (DA) shoulder. Functional testing revealed a positive impingement sign in 6/21 DA shoulders. Supraspinatus testing showed abnormalities in 4/21 DA shoulders. Pain was referred posteriorly with the impingement maneuver in 5/21 DA shoulders and abnormal external rotation testing was observed in 8/21 DA shoulders. Generally, the females had proportionally more signs and symptoms of shoulder injury than the men, especially involving the DA shoulder. Testing implicated supraspinatus impingement/tendonitis and infraspinatus/teres minor traction tendonitis. These clinical findings correlated with cadaver prosection observations.

  10. Verification of joint input-state estimation for force identification by means of in situ measurements on a footbridge

    NASA Astrophysics Data System (ADS)

    Maes, K.; Nimmen, K. Van; Lourens, E.; Rezayat, A.; Guillaume, P.; Roeck, G. De; Lombaert, G.

    2016-06-01

    This paper presents a verification of a joint input-state estimation algorithm using data obtained from in situ experiments on a footbridge. The estimation of the input and the system states is performed in a minimum-variance unbiased way, based on a limited number of response measurements and a system model. A dynamic model of the footbridge is obtained using a detailed finite element model that is updated using a set of experimental modal characteristics. The joint input-state estimation algorithm is used for the identification of two impact, harmonic, and swept sine forces applied to the bridge deck. In addition to these forces, unknown stochastic forces, such as wind loads, are acting on the structure. These forces, as well as measurement errors, give rise to uncertainty in the estimated forces and system states. Quantification of the uncertainty requires determination of the power spectral density of the unknown stochastic excitation, which is identified from the structural response under ambient loading. The verification involves comparing the estimated forces with the actual, measured forces. Although a good overall agreement is obtained between the estimated and measured forces, modeling errors prohibit a proper distinction between multiple forces applied to the structure for the case of harmonic and swept sine excitation.

  11. Reflex Responsiveness of a Human Hand Muscle When Controlling Isometric Force and Joint Position

    PubMed Central

    Maluf, Katrina S.; Barry, Benjamin K.; Riley, Zachary A.; Enoka, Roger M.

    2007-01-01

    Objective This study compared reflex responsiveness of the first dorsal interosseus muscle during two tasks that employ different strategies to stabilize the finger while exerting the same net muscle torque. Methods Healthy human subjects performed two motor tasks that involved either pushing up against a rigid restraint to exert a constant isometric force equal to 20% of maximum, or maintaining a constant angle at the metacarpophalangeal joint while supporting an equivalent inertial load. Each task consisted of six 40-s contractions during which electrical and mechanical stimuli were delivered. Results The amplitude of short and long latency reflex responses to mechanical stretch did not differ significantly between tasks. In contrast, reflexes evoked by electrical stimulation were significantly greater when supporting the inertial load. Conclusions Agonist motor neurons exhibited heightened reflex responsiveness to synaptic input from heteronymous afferents when controlling the position of an inertial load. Task differences in the reflex response to electrical stimulation were not reflected in the response to mechanical perturbation, indicating a difference in the efficacy of the pathways that mediate these effects. Significance Results from this study suggest that modulation of spinal reflex pathways may contribute to differences in the control of force and position during isometric contractions of the first dorsal interosseus muscle. PMID:17646129

  12. Spacecraft environmental interactions: A joint Air Force and NASA research and technology program

    NASA Technical Reports Server (NTRS)

    Pike, C. P.; Purvis, C. K.; Hudson, W. R.

    1985-01-01

    A joint Air Force/NASA comprehensive research and technology program on spacecraft environmental interactions to develop technology to control interactions between large spacecraft systems and the charged-particle environment of space is described. This technology will support NASA/Department of Defense operations of the shuttle/IUS, shuttle/Centaur, and the force application and surveillance and detection missions, planning for transatmospheric vehicles and the NASA space station, and the AFSC military space system technology model. The program consists of combined contractual and in-house efforts aimed at understanding spacecraft environmental interaction phenomena and relating results of ground-based tests to space conditions. A concerted effort is being made to identify project-related environmental interactions of concern. The basic properties of materials are being investigated to develop or modify the materials as needed. A group simulation investigation is evaluating basic plasma interaction phenomena to provide inputs to the analytical modeling investigation. Systems performance is being evaluated by both groundbased tests and analysis.

  13. Like Father, Like Son: Assessment of the Morphological Affinities of A.L. 288–1 (A. afarensis), Sts 7 (A. africanus) and Omo 119–73–2718 (Australopithecus sp.) through a Three-Dimensional Shape Analysis of the Shoulder Joint

    PubMed Central

    Arias-Martorell, Julia; Potau, Josep Maria; Bello-Hellegouarch, Gaëlle; Pérez-Pérez, Alejandro

    2015-01-01

    The postcranial evidence for the Australopithecus genus indicates that australopiths were able bipeds; however, the morphology of the forelimbs and particularly that of the shoulder girdle suggests that they were partially adapted to an arboreal lifestyle. The nature of such arboreal adaptations is still unclear, as are the kind of arboreal behaviors in which australopiths might have engaged. In this study we analyzed the shape of the shoulder joint (proximal humerus and glenoid cavity of the scapula) of three australopith specimens: A.L. 288–1 (A. afarensis), Sts 7 (A. africanus) and Omo 119–73–2718 (Australopithecus sp.) with three-dimensional geometric morphometrics. The morphology of the specimens was compared with that of a wide array of living anthropoid taxa and some additional fossil hominins (the Homo erectus specimen KNM-WT 15000 and the H. neanderthalensis specimen Tabun 1). Our results indicate that A.L. 288–1 shows mosaic traits resembling H. sapiens and Pongo, whereas the Sts 7 shoulder is most similar to the arboreal apes and does not present affinities with H. sapiens. Omo 119–73–2718 exhibits morphological affinities with the more arboreal and partially suspensory New World monkey Lagothrix. The shoulder of the australopith specimens thus shows a combination of primitive and derived traits (humeral globularity, enhancement of internal and external rotation of the joint), related to use of the arm in overhead positions. The genus Homo specimens show overall affinities with H. sapiens at the shoulder, indicating full correspondence of these hominin shoulders with the modern human morphotype. PMID:25651542

  14. Like father, like son: assessment of the morphological affinities of A.L. 288-1 (A. afarensis), Sts 7 (A. africanus) and Omo 119-73-2718 (Australopithecus sp.) through a three-dimensional shape analysis of the shoulder joint.

    PubMed

    Arias-Martorell, Julia; Potau, Josep Maria; Bello-Hellegouarch, Gaëlle; Pérez-Pérez, Alejandro

    2015-01-01

    The postcranial evidence for the Australopithecus genus indicates that australopiths were able bipeds; however, the morphology of the forelimbs and particularly that of the shoulder girdle suggests that they were partially adapted to an arboreal lifestyle. The nature of such arboreal adaptations is still unclear, as are the kind of arboreal behaviors in which australopiths might have engaged. In this study we analyzed the shape of the shoulder joint (proximal humerus and glenoid cavity of the scapula) of three australopith specimens: A.L. 288-1 (A. afarensis), Sts 7 (A. africanus) and Omo 119-73-2718 (Australopithecus sp.) with three-dimensional geometric morphometrics. The morphology of the specimens was compared with that of a wide array of living anthropoid taxa and some additional fossil hominins (the Homo erectus specimen KNM-WT 15000 and the H. neanderthalensis specimen Tabun 1). Our results indicate that A.L. 288-1 shows mosaic traits resembling H. sapiens and Pongo, whereas the Sts 7 shoulder is most similar to the arboreal apes and does not present affinities with H. sapiens. Omo 119-73-2718 exhibits morphological affinities with the more arboreal and partially suspensory New World monkey Lagothrix. The shoulder of the australopith specimens thus shows a combination of primitive and derived traits (humeral globularity, enhancement of internal and external rotation of the joint), related to use of the arm in overhead positions. The genus Homo specimens show overall affinities with H. sapiens at the shoulder, indicating full correspondence of these hominin shoulders with the modern human morphotype.

  15. Specific Shoulder Pathoanatomy in Semiprofessional Water Polo Players

    PubMed Central

    Klein, Maria; Tarantino, Ignazio; Warschkow, René; Berger, Claus Joachim; Zdravkovic, Vilijam; Jost, Bernhard; Badulescu, Michael

    2014-01-01

    Background: Shoulders of throwing and swimming athletes are highly stressed joints that often show structural abnormalities on magnetic resonance imaging (MRI). However, while water polo players exhibit a combination of throwing and swimming movements, a specific pattern of pathological findings has not been described. Purpose: To assess specific MRI abnormalities in shoulders of elite water polo players and to compare these findings with a healthy control group. Study Design: Cross-sectional study; Level of evidence, 3. Methods: After performing a power analysis, volunteers were recruited for this study. Both shoulders of 28 semiprofessional water polo players and 15 healthy volunteers were assessed clinically (based on the Constant score) and had bilateral shoulder MRIs. The shoulders were clustered into 3 groups: 28 throwing and 28 nonthrowing shoulders of water polo athletes and 30 shoulders of healthy control subjects. Results: Twenty-eight male water polo players with an average age of 24 years and 15 healthy subjects (30 shoulders) with an average age of 31 years were examined. Compared with controls, significantly more MRI abnormalities in the water polo players' throwing shoulders could be found in the subscapularis, infraspinatus, and posterior labrum (P = .001, P = .024, and P = .041, respectively). Other structures showed no statistical differences between the 3 groups, including the supraspinatus tendon, which had abnormalities in 36% of throwing versus 32% of nonthrowing shoulders and 33% of control shoulders. All throwing shoulders showed abnormal findings in the MRI, but only 8 (29%) were symptomatic. Conclusion: The shoulders of semiprofessional water polo players demonstrated abnormalities in subscapularis and infraspinatus tendons that were not typical abnormalities for swimmers or throwing athletes. Clinical Relevance: The throwing shoulders of water polo players have specific MRI changes. Clinical symptoms do not correlate with the MRI findings

  16. Managing shoulder dystocia.

    PubMed

    Brew, J

    1993-01-01

    In midwifery textbooks not much has been written about the management of shoulder dystocia, although it sometimes occurs, and midwives conducting the delivery have to know how to manage it. Should dystocia occurs when the shoulders are stuck in the antero-posterior diameter of the outlet. Sometimes the shoulders fail to rotate into the antero-posterior diameter; in this situation the shoulders are in the oblique diameter of the outlet. This usually happens when the baby is big, weighing more than 4 kilograms. In such cases, the head is big, and it is difficult to deliver the face and the chin. The woman should be in lithotomy position, with the buttocks slightly beyond the end of the bed. The baby's air passages should be sucked of mucus and liquid, so that respiration is initiated. A wide episiotomy should be performed to enlarge the outlet. If the shoulders are in the oblique diameter of the outlet, the midwife should correct the position by hooking a finger into the anterior axilla and rotate the shoulders forward to the antero-posterior diameter of the outlet, before attempting to deliver the shoulders. The next step is the delivery of the posterior shoulder. The midwife puts a finger into the axilla of the posterior shoulder, and by gentle traction downwards, the posterior shoulder is freed. After this, the anterior shoulder is delivered the normal way. This can be aided by applying pressure on the anterior shoulder above the pubic. If the above management fails, then the assistance of the obstetrician must be sought. It is important to recognize large babies before birth in order to initiate appropriate measures before the woman goes into labor. During delivery, the shoulders must be rotated into the antero-posterior diameter of the outlet before attempting to deliver them.

  17. On the organizing role of nonmuscular forces during performance of a giant circle in gymnastics.

    PubMed

    Sevrez, Violaine; Rao, Guillaume; Berton, Eric; Bootsma, Reinoud J

    2012-02-01

    Five elite gymnasts performed giant circles on the high bar under different conditions of loading (without and with 6-kg loads attached to the shoulders, waist or ankles). Comparing the gymnasts' kinematic pattern of movement with that of a triple-pendulum moving under the sole influence of nonmuscular forces revealed qualitative similarities, including the adoption of an arched position during the downswing and a piked position during the upswing. The structuring role of nonmuscular forces in the organization of movement was further reinforced by the results of an inverse dynamics analysis, assessing the contributions of gravitational, inertial and muscular components to the net joint torques. Adding loads at the level of the shoulders, waist or ankles systematically influenced movement kinematics and net joint torques. However, with the loads attached at the level of the shoulders or waist, the load-induced changes in gravitational and inertial torques provided the required increase in net joint torque, thereby allowing the muscular torques to remain unchanged. With the loads attached at the level of the ankles, this was no longer the case and the gymnasts increased the muscular torques at the shoulder and hip joints. Together, these results demonstrate that expert gymnasts skillfully exploit the operative nonmuscular forces, employing muscle force only in the capacity of complementary forces needed to perform the task.

  18. A neural network approach for determining gait modifications to reduce the contact force in knee joint implant.

    PubMed

    Ardestani, Marzieh Mostafavizadeh; Chen, Zhenxian; Wang, Ling; Lian, Qin; Liu, Yaxiong; He, Jiankang; Li, Dichen; Jin, Zhongmin

    2014-10-01

    There is a growing interest in non-surgical gait rehabilitation treatments to reduce the loading in the knee joint. In particular, synergetic kinematic changes required for joint offloading should be determined individually for each subject. Previous studies for gait rehabilitation designs are typically relied on a "trial-and-error" approach, using multi-body dynamic (MBD) analysis. However MBD is fairly time demanding which prevents it to be used iteratively for each subject. This study employed an artificial neural network to develop a cost-effective computational framework for designing gait rehabilitation patterns. A feed forward artificial neural network (FFANN) was trained based on a number of experimental gait trials obtained from literature. The trained network was then hired to calculate the appropriate kinematic waveforms (output) needed to achieve desired knee joint loading patterns (input). An auxiliary neural network was also developed to update the ground reaction force and moment profiles with respect to the predicted kinematic waveforms. The feasibility and efficiency of the predicted kinematic patterns were then evaluated through MBD analysis. Results showed that FFANN-based predicted kinematics could effectively decrease the total knee joint reaction forces. Peak values of the resultant knee joint forces, with respect to the bodyweight (BW), were reduced by 20% BW and 25% BW in the midstance and the terminal stance phases. Impulse values of the knee joint loading patterns were also decreased by 17% BW*s and 24%BW*s in the corresponding phases. The FFANN-based framework suggested a cost-effective forward solution which directly calculated the kinematic variations needed to implement a given desired knee joint loading pattern. It is therefore expected that this approach provides potential advantages and further insights into knee rehabilitation designs.

  19. Assessing Finger Joint Biomechanics by Applying Equal Force to Flexor Tendons In Vitro Using a Novel Simultaneous Approach

    PubMed Central

    Yang, Tai-Hua; Lu, Szu-Ching; Lin, Wei-Jr; Zhao, Kristin; Zhao, Chunfeng; An, Kai-Nan; Jou, I-Ming; Lee, Pei-Yuan

    2016-01-01

    Background The flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) are critical for finger flexion. Although research has recently focused on these tendons’ coactivity, their contributions in different tasks remain unclear. This study created a novel simultaneous approach to investigate the coactivity between the tendons and to clarify their contributions in different tasks. Methods Ten human cadaveric hands were mounted on our custom frame with the FDS and FDP of the third finger looped through a mechanical pulley connected to a force transducer. Joint range of motion, tendon excursion and loading force were recorded during individual joint motion and free joint movement from rest to maximal flexion. Each flexor tendon’s moment arm was then calculated. Results In individual motions, we found that the FDP contributed more than the FDS in proximal interphalangeal (PIP) joint motion, with an overall slope of 1.34 and all FDP-to-FDS excursion (P/S) ratios greater than 1.0 with force increase. However, the FDP contributed less than the FDS in metacarpophalangeal (MCP) joint motion, with an overall slope of 0.95 and P/S ratios smaller than 1.0 throughout the whole motion except between 1.9% and 13.1% force. In free joint movement, the FDP played a greater role than the FDS, with an overall ratio of 1.37 and all P/S ratios greater than 1.0. Conclusions The new findings include differences in finger performance and excursion amounts between the FDS and FDP throughout flexion. Such findings may provide the basis for new hand models and treatments. PMID:27513744

  20. Sonographic Evaluation of Structural Changes in Post-Stroke Hemiplegic Shoulders

    PubMed Central

    Idowu, Bukunmi Michael; Ayoola, Oluwagbemiga Oluwole; Adetiloye, Victor Adebayo; Komolafe, Morenikeji Adeyoyin

    2017-01-01

    Summary Background Stroke and hemiplegia are frequent complications of stroke. This study was performed to sonographically evaluate post-stroke hemiplegic shoulders and explore possible relationship(s) between the sonographic findings and clinical indices. Material/Methods Forty-five stroke patients and 45 age- and sex-matched controls were recruited. Standard sonographic examination of both shoulders was performed to assess for joint subluxation, rotator cuff tears, tendinosis, subacromial-subdeltoid bursitis or effusion and adhesive capsulitis. Results Hemiplegic shoulders exhibited significantly higher number of pathologies compared to the unaffected shoulders and shoulders of controls (p=0.000). One or more structural abnormalities were found in all 45 (100%) hemiplegic shoulders, 25 (55.6%) unaffected shoulders of the stroke subjects, and 39 (43.3%) control shoulders. The most frequent pathologies in the hemiplegic shoulders were the following: tendinosis of the long head of bicep tendon (48.9%), inferior shoulder subluxation (44.4%), co-existing subacromial-subdeltoid bursa/long head of bicep tendon sheath effusion (44.4%), and long head of bicep tendon sheath effusion only (40%). Tendinosis of the long head of bicep tendon was commoner in hemiplegic shoulders with poor motor status than those with good motor status. Conclusions Hemiplegic shoulders have significantly higher number of structural abnormalities than unaffected shoulders and the shoulders of controls. Hemiplegic stroke patients should undergo ultrasonography of the hemiplegic shoulder to define the nature and extent of soft tissue injuries prior to physical therapy. PMID:28382186

  1. US anatomy of the shoulder: Pictorial essay.

    PubMed

    Precerutti, M; Garioni, E; Madonia, L; Draghi, F

    2010-12-01

    A thorough knowledge of the anatomy of the shoulder is essential for the assessment of its condition. The purpose of this article is to provide a useful tool for the ultrasound (US) study of this joint. The shoulder girdle and upper arm are made up of a number of muscles and tendons: rotator cuff (supraspinatus, infraspinatus, teres minor and subscapularis), humeral biceps, deltoid and pectoral muscles, which can all be evaluated at US examination. Various and complex capsular ligamentous structures contribute to the stability of the shoulder, but only a few can be adequately evaluated by US and will therefore receive particular attention. Numerous serous bursae are situated among muscles, skin, subcutaneous tissues, joint capsule structures and bones to prevent friction and they can be evaluated by US only in the presence of pathologies. Subacromial-subdeltoid and subcoracoid bursa are most frequently involved and will therefore be described in detail. There are furthermore nerves and vessels providing the various components of the shoulder with innervation and vascularization, and they can also be studied by US. The shoulder girdle (humerus, scapula, clavicle and sternal manubrium) is situated in the deep layers; only the cortex of the bone can be seen at US as a continuous hyperechoic line. For a better understanding of the location and relationship between the structures which can be studied by US, magnetic resonance imaging (MRI) can be carried out as this method provides a wider and more complete view of the structures.

  2. Bony instability of the shoulder.

    PubMed

    Bushnell, Brandon D; Creighton, R Alexander; Herring, Marion M

    2008-09-01

    Instability of the shoulder is a common problem treated by many orthopaedists. Instability can result from baseline intrinsic ligamentous laxity or a traumatic event-often a dislocation that injures the stabilizing structures of the glenohumeral joint. Many cases involve soft-tissue injury only and can be treated successfully with repair of the labrum and ligamentous tissues. Both open and arthroscopic approaches have been well described, with recent studies of arthroscopic soft-tissue techniques reporting results equal to those of the more traditional open techniques. Over the last decade, attention has focused on the concept of instability of the shoulder mediated by bony pathology such as a large bony Bankart lesion or an engaging Hill-Sachs lesion. Recent literature has identified unrecognized large bony lesions as a primary cause of failure of arthroscopic reconstruction for instability, a major cause of recurrent instability, and a difficult diagnosis to make. Thus, although such bony lesions may be relatively rare compared with soft-tissue pathology, they constitute a critically important entity in the management of shoulder instability. Smaller bony lesions may be amenable to arthroscopic treatment, but larger lesions often require open surgery to prevent recurrent instability. This article reviews recent developments in the diagnosis and treatment of bony instability.

  3. Incidence of Posttraumatic Shoulder Dislocation in Poland

    PubMed Central

    Szyluk, Karol J.; Jasiński, Andrzej; Mielnik, Michał; Koczy, Bogdan

    2016-01-01

    Background The incidence of shoulder joint dislocation has been estimated at 11–26 per 100 000 population per year. In our opinion, basic epidemiological data need to be continually updated in studies of large populations. To study the incidence of posttraumatic dislocation of the shoulder joint in the Polish population. Material/Methods We retrospectively investigated the entire Polish population between 1 January 2010 and 1 January 2015. To identify the study group, data collected in the electronic database of the National Health Fund were used. The study group was divided into subgroups to detect possible differences in the incidence of shoulder dislocation with regard to age, sex, and season of the year (month) when the dislocation occurred. Results The cumulative size of the study sample was 192.72 million over the 5 years of the study. We identified 51 409 patients with first posttraumatic shoulder dislocation, at a mean age of 50.83 years (SD 21.12), from 0 to 104 years. The incidence of traumatic shoulder dislocations for the entire study group ranged from 24.75/100 000/year (number of posttraumatic shoulder dislocations per 100 000 persons per year) to 29.09/100 000/year, for a mean of 26.69/100 000/year. Conclusions In this study, the overall incidence of first-time posttraumatic shoulder dislocations in the Polish general population was 26.69 per 100 000 persons per year. These results are higher than estimates presented by other authors. It is necessary to study, regularly update, and monitor this problem in the general population. PMID:27777396

  4. Proximal arm kinematics affect grip force-load force coordination.

    PubMed

    Vermillion, Billy C; Lum, Peter S; Lee, Sang Wook

    2015-10-01

    During object manipulation, grip force is coordinated with load force, which is primarily determined by object kinematics. Proximal arm kinematics may affect grip force control, as proximal segment motion could affect control of distal hand muscles via biomechanical and/or neural pathways. The aim of this study was to investigate the impact of proximal kinematics on grip force modulation during object manipulation. Fifteen subjects performed three vertical lifting tasks that involved distinct proximal kinematics (elbow/shoulder), but resulted in similar end-point (hand) trajectories. While temporal coordination of grip and load forces remained similar across the tasks, proximal kinematics significantly affected the grip force-to-load force ratio (P = 0.042), intrinsic finger muscle activation (P = 0.045), and flexor-extensor ratio (P < 0.001). Biomechanical coupling between extrinsic hand muscles and the elbow joint cannot fully explain the observed changes, as task-related changes in intrinsic hand muscle activation were greater than in extrinsic hand muscles. Rather, between-task variation in grip force (highest during task 3) appears to contrast to that in shoulder joint velocity/acceleration (lowest during task 3). These results suggest that complex neural coupling between the distal and proximal upper extremity musculature may affect grip force control during movements, also indicated by task-related changes in intermuscular coherence of muscle pairs, including intrinsic finger muscles. Furthermore, examination of the fingertip force showed that the human motor system may attempt to reduce variability in task-relevant motor output (grip force-to-load force ratio), while allowing larger fluctuations in output less relevant to task goal (shear force-to-grip force ratio).

  5. Shoulder imaging in athletes.

    PubMed

    Tirman, Phillip F; Smith, Eric D; Stoller, David W; Fritz, Russell C

    2004-03-01

    Shoulder pain and injuries are common in athletes. Overhead athletes, in particular, place great demands on the shoulder and supporting structures. Magnetic resonance (MR) imaging is well suited to evaluation of the osseous structures and soft tissues of the shoulder and plays an important role in evaluation of shoulder pain in athletes. Primary extrinsic impingement is well evaluated on MR imaging as are the less common posterior superior glenoid impingement and subcoracoid impingement. Rotator cuff tendinosis as well as partial- and full-thickness tears are frequently encountered in the athletic shoulder. The biceps tendon and rotator interval capsular structures are important sources of shoulder pain. Glenohumeral instability that results from a traumatic event or atraumatic multidirectional recurrent instability is assessed. The biceps labral complex is a source of considerable anatomic variability and pathology.

  6. A 3D lower limb musculoskeletal model for simultaneous estimation of musculo-tendon, joint contact, ligament and bone forces during gait.

    PubMed

    Moissenet, Florent; Chèze, Laurence; Dumas, Raphaël

    2014-01-03

    Musculo-tendon forces and joint reaction forces are typically estimated using a two-step method, computing first the musculo-tendon forces by a static optimization procedure and then deducing the joint reaction forces from the force equilibrium. However, this method does not allow studying the interactions between musculo-tendon forces and joint reaction forces in establishing this equilibrium and the joint reaction forces are usually overestimated. This study introduces a new 3D lower limb musculoskeletal model based on a one-step static optimization procedure allowing simultaneous musculo-tendon, joint contact, ligament and bone forces estimation during gait. It is postulated that this approach, by giving access to the forces transmitted by these musculoskeletal structures at hip, tibiofemoral, patellofemoral and ankle joints, modeled using anatomically consistent kinematic models, should ease the validation of the model using joint contact forces measured with instrumented prostheses. A blinded validation based on four datasets was made under two different minimization conditions (i.e., C1 - only musculo-tendon forces are minimized, and C2 - musculo-tendon, joint contact, ligament and bone forces are minimized while focusing more specifically on tibiofemoral joint contacts). The results show that the model is able to estimate in most cases the correct timing of musculo-tendon forces during normal gait (i.e., the mean coefficient of active/inactive state concordance between estimated musculo-tendon force and measured EMG envelopes was C1: 65.87% and C2: 60.46%). The results also showed that the model is potentially able to well estimate joint contact, ligament and bone forces and more specifically medial (i.e., the mean RMSE between estimated joint contact force and in vivo measurement was C1: 1.14BW and C2: 0.39BW) and lateral (i.e., C1: 0.65BW and C2: 0.28BW) tibiofemoral contact forces during normal gait. However, the results remain highly influenced by the

  7. Development and performance evaluation of a multi-PID muscle loading driven in vitro active-motion shoulder simulator and application to assessing reverse total shoulder arthroplasty.

    PubMed

    Giles, Joshua William; Ferreira, Louis Miguel; Athwal, George Singh; Johnson, James Andrew

    2014-12-01

    In vitro active shoulder motion simulation can provide improved understanding of shoulder biomechanics; however, accurate simulators using advanced control theory have not been developed. Therefore, our objective was to develop and evaluate a simulator which uses real-time kinematic feedback and closed loop proportional integral differential (PID) control to produce motion. The simulator's ability to investigate a clinically relevant variable-namely muscle loading changes resulting from reverse total shoulder arthroplasty (RTSA)-was evaluated and compared to previous findings to further demonstrate its efficacy. Motion control of cadaveric shoulders was achieved by applying continuously variable forces to seven muscle groups. Muscle forces controlling each of the three glenohumeral rotational degrees of freedom (DOF) were modulated using three independent PID controllers running in parallel, each using measured Euler angles as their process variable. Each PID controller was configured and tuned to control the loading of a set of muscles which, from previous in vivo investigations, were found to be primarily responsible for movement in the PID's DOF. The simulator's ability to follow setpoint profiles for abduction, axial rotation, and horizontal extension was assessed using root mean squared error (RMSE) and average standard deviation (ASD) for multiple levels of arm mass replacement. A specimen was then implanted with an RTSA, and the effect of joint lateralization (0, 5, 10 mm) on the total deltoid force required to produce motion was assessed. Maximum profiling error was <2.1 deg for abduction and 2.2 deg for horizontal extension with RMSE of <1 deg. The nonprofiled DOF were maintained to within 5.0 deg with RMSE <1.0 deg. Repeatability was high, with ASDs of <0.31 deg. RMSE and ASD were similar for all levels of arm mass replacement (0.73-1.04 and 0.14-0.22 deg). Lateralizing the joint's center of rotation (CoR) increased total deltoid force by up to 8.5% body

  8. The developing shoulder has a limited capacity to recover after a short duration of neonatal paralysis.

    PubMed

    Potter, Ryan; Havlioglu, Necat; Thomopoulos, Stavros

    2014-07-18

    Mechanical stimuli are required for the proper development of the musculoskeletal system. Removal of muscle forces during fetal or early post-natal timepoints impairs the formation of bone, tendon, and their attachment (the enthesis). The goal of the current study was to examine the capacity of the shoulder to recover after a short duration of neonatal rotator cuff paralysis, a condition mimicking the clinical condition neonatal brachial plexus palsy. We asked if reapplication of muscle load to a transiently paralyzed muscle would allow for full recovery of tissue properties. CD-1 mice were injected with botulinum toxin A to paralyze the supraspinatus muscle from birth through 2 weeks and subsequently allowed to recover. The biomechanics of the enthesis was determined using tensile testing and the morphology of the shoulder joint was determined using microcomputed tomography and histology. A recovery period of at least 10 weeks was required to achieve control properties, demonstrating a limited capacity of the shoulder to recover after only two weeks of muscle paralysis. Although care must be taken when extrapolating results from an animal model to the human condition, the results of the current study imply that treatment of neonatal brachial plexus palsy should be aggressive, as even short periods of paralysis could lead to long-term deficiencies in enthesis biomechanics and shoulder morphology.

  9. Shoulder pathoanatomy in marathon kayakers

    PubMed Central

    Hagemann, G; Rijke, A; Mars, M

    2004-01-01

    Objectives: To determine the prevalence of soft and hard tissue abnormalities and their interrelations in the shoulders of marathon kayakers and to examine the pathoanatomical factors that predispose these athletes to injury. Methods: Fifty two long distance kayakers completed a questionnaire. Their shoulders were examined for range of motion, pain, and stability using a standard set of 10 clinical tests. The shoulder was subsequently scanned by magnetic resonance imaging (MRI) in three planes and evaluated for evidence of injury or other abnormality. The relation of clinical symptoms and MRI findings was investigated with respect to kayaker's age, number of years kayaking, and number of marathon races completed. Results: Thirty subjects were asymptomatic at the time of scanning, and twenty two showed symptoms of pain and/or instability. MRI showed acromioclavicular hypertrophy, acromial or clavicular spur, supraspinatus tendinitis, and partial tear of the supraspinatus as the most common abnormalities. Kayaker's age, number of years kayaking, and number of races completed did not relate significantly to symptoms or to the presence of an abnormality on MRI scan. Of all the pathoanatomical findings that are reported to predispose to rotator cuff injury, only acromial and clavicular spurs were found to correlate highly with supraspinatus muscle pathology. Conclusions: Rotator cuff injuries make up a large portion of the injuries seen in marathon kayakers, about twice the number reported for sprint kayakers. These injuries are the result of secondary impingement factors associated with overuse, possibly specific to kayakers, and not the result of bony restrictions around the shoulder joint. Acromioclavicular hypertrophy is a common finding in marathon kayakers, but is possibly the result of portaging or a previous injury. PMID:15273173

  10. Joint positioning sense, perceived force level and two-point discrimination tests of young and active elderly adults

    PubMed Central

    Franco, Priscila G.; Santos, Karini B.; Rodacki, André L. F.

    2015-01-01

    Background: Changes in the proprioceptive system are associated with aging. Proprioception is important to maintaining and/or recovering balance and to reducing the risk of falls. Objective: To compare the performance of young and active elderly adults in three proprioceptive tests. Method: Twenty-one active elderly participants (66.9±5.5 years) and 21 healthy young participants (24.6±3.9 years) were evaluated in the following tests: perception of position of the ankle and hip joints, perceived force level of the ankle joint, and two-point discrimination of the sole of the foot. Results: No differences (p>0.05) were found between groups for the joint position and perceived force level. On the other hand, the elderly participants showed lower sensitivity in the two-point discrimination (higher threshold) when compared to the young participants (p < 0.01). Conclusion: Except for the cutaneous plantar sensitivity, the active elderly participants had maintained proprioception. Their physical activity status may explain similarities between groups for the joint position sense and perceived force level, however it may not be sufficient to prevent sensory degeneration with aging. PMID:26443978

  11. Subject-specific hip geometry and hip joint centre location affects calculated contact forces at the hip during gait.

    PubMed

    Lenaerts, G; Bartels, W; Gelaude, F; Mulier, M; Spaepen, A; Van der Perre, G; Jonkers, I

    2009-06-19

    Hip loading affects the development of hip osteoarthritis, bone remodelling and osseointegration of implants. In this study, we analyzed the effect of subject-specific modelling of hip geometry and hip joint centre (HJC) location on the quantification of hip joint moments, muscle moments and hip contact forces during gait, using musculoskeletal modelling, inverse dynamic analysis and static optimization. For 10 subjects, hip joint moments, muscle moments and hip loading in terms of magnitude and orientation were quantified using three different model types, each including a different amount of subject-specific detail: (1) a generic scaled musculoskeletal model, (2) a generic scaled musculoskeletal model with subject-specific hip geometry (femoral anteversion, neck-length and neck-shaft angle) and (3) a generic scaled musculoskeletal model with subject-specific hip geometry including HJC location. Subject-specific geometry and HJC location were derived from CT. Significant differences were found between the three model types in HJC location, hip flexion-extension moment and inclination angle of the total contact force in the frontal plane. No model agreement was found between the three model types for the calculation of contact forces in terms of magnitude and orientations, and muscle moments. Therefore, we suggest that personalized models with individualized hip joint geometry and HJC location should be used for the quantification of hip loading. For biomechanical analyses aiming to understand modified hip joint loading, and planning hip surgery in patients with osteoarthritis, the amount of subject-specific detail, related to bone geometry and joint centre location in the musculoskeletal models used, needs to be considered.

  12. Operational Stress and Correlates of Mental Health Among Joint Task Force Guantanamo Bay Military Personnel.

    PubMed

    Webb-Murphy, Jennifer A; De La Rosa, Gabriel M; Schmitz, Kimberly J; Vishnyak, Elizabeth J; Raducha, Stephanie C; Roesch, Scott C; Johnston, Scott L

    2015-12-01

    Military personnel deployed to Joint Task Force Guantanamo Bay (JTF-GTMO) faced numerous occupational stressors. As part of a program evaluation, personnel working at JTF-GTMO completed several validated self-report measures. Personnel were at the beginning, middle, or end of their deployment phase. This study presents data regarding symptoms of posttraumatic stress disorder, alcohol abuse, depression, and resilience among 498 U.S. military personnel deployed to JTF-GTMO in 2009. We also investigated individual and organizational correlates of mental health among these personnel. Findings indicated that tenure at JTF-GTMO was positively related to adverse mental health outcomes. Regression models including these variables had R2 values ranging from .02 to .11. Occupation at JTF-GTMO also related to mental health such that guards reported poorer mental health than medical staff. Reluctance to seek out mental health care was also related to mental health outcomes. Those who reported being most reluctant to seek out care tended to report poorer mental health than those who were more willing to seek out care. Results suggested that the JTF-GTMO deployment was associated with significant psychological stress, and that both job-related and attitude-related variables were important to understanding mental health symptoms in this sample.

  13. Higher medially-directed joint reaction forces are a characteristic of dysplastic hips: A comparative study using subject-specific musculoskeletal models.

    PubMed

    Harris, Michael D; MacWilliams, Bruce A; Bo Foreman, K; Peters, Christopher L; Weiss, Jeffrey A; Anderson, Andrew E

    2017-03-21

    Acetabular dysplasia is a known cause of hip osteoarthritis. In addition to abnormal anatomy, changes in kinematics, joint reaction forces (JRFs), and muscle forces could cause tissue damage to the cartilage and labrum, and may contribute to pain and fatigue. The objective of this study was to compare lower extremity joint angles, moments, hip JRFs and muscle forces during gait between patients with symptomatic acetabular dysplasia and healthy controls. Marker trajectories and ground reaction forces were measured in 10 dysplasia patients and 10 typically developing control subjects. A musculoskeletal model was scaled in OpenSim to each subject and subject-specific hip joint centers were determined using reconstructions from CT images. Joint kinematics and moments were calculated using inverse kinematics and inverse dynamics, respectively. Muscle forces and hip JRFs were estimated with static optimization. Inter-group differences were tested for statistical significance (p≤0.05) and large effect sizes (d≥0.8). Results demonstrated that dysplasia patients had higher medially directed JRFs. Joint angles and moments were mostly similar between the groups, but large inter-group effect sizes suggested some restriction in range of motion by patients at the hip and ankle. Higher medially-directed JRFs and inter-group differences in hip muscle forces likely stem from lateralization of the hip joint center in dysplastic patients. Joint force differences, combined with reductions in range of motion at the hip and ankle may also indicate compensatory strategies by patients with dysplasia to maintain joint stability.

  14. Joint Force Quarterly. Number 17, Autumn/Winter 1997-98

    DTIC Science & Technology

    1998-02-01

    Four Corners, Route 914 carried traffic from numerous sources, including Mu Gia Pass and inland waterways. With a width of 8 to 30 feet and a laterite ...still had greater potential than others: a stable base, crushed stone and laterite surfaces averaging 13 to 14 feet in width (less shoulders), gradients...130 transports until January 1968, when NVA regulars overran it on their way to Khe Sanh shortly before Tet. The crushed stone and laterite runway

  15. Quantification of the role of tibial posterior slope in knee joint mechanics and ACL force in simulated gait.

    PubMed

    Marouane, H; Shirazi-Adl, A; Hashemi, J

    2015-07-16

    The anterior cruciate ligament (ACL) rupture is a common knee joint injury with higher prevalence in female athletes. In search of contributing mechanisms, clinical imaging studies of ACL-injured individuals versus controls have found greater medial-lateral posterior tibial slope (PTS) in injured population irrespective of the sex and in females compared to males, with stronger evidence on the lateral plateau slope. To quantify these effects, we use a lower extremity musculoskeletal model including a detailed finite element (FE) model of the knee joint to compute the role of changes in medial and/or lateral PTS by ±5° and ±10° on knee joint biomechanics, in general, and ACL force, in particular, throughout the stance phase of gait. The model is driven by reported kinematics/kinetics of gait in asymptomatic subjects. Our predictions showed, at all stance periods, a substantial increase in the anterior tibial translation (ATT) and ACL force as PTS increased with reverse trends as PTS decreased. At mid-stance, for example, ACL force increased from 181 N to 317 N and 460 N as PTS increased by 5° and 10°, respectively, while dropped to 102 N and 0 N as PTS changed by -5° and -10°, respectively. These effects are caused primarily by change in PTS at the tibial plateau that carries a larger portion of joint contact force. Steeper PTS is a major risk factor, especially under activities with large compression, in markedly increasing ACL force and its vulnerability to injury. Rehabilitation and ACL injury prevention programs could benefit from these findings.

  16. Rehabilitation of the pitching shoulder.

    PubMed

    Pappas, A M; Zawacki, R M; McCarthy, C F

    1985-01-01

    Shoulder pain is a common complaint among baseball pitchers. Frequently, the nature of shoulder pathology can be traced to lack of flexibility and muscular imbalance. This paper describes: the normal biomechanics of a properly functioning shoulder during a baseball pitch, pathomechanics of shoulder problems, flexibility requirements of the throwing shoulder, and the muscular balance necessary for an effective throwing shoulder. Appropriate examination procedures are described along with remedial exercises which ensure normal glenohumeral motion and integrated muscle action.

  17. Shoulder girdle elevation during neurodynamic testing: an assessable sign?

    PubMed

    Coppieters, M W; Stappaerts, K H; Staes, F F; Everaert, D G

    2001-05-01

    One of the signs advocated for monitoring during neurodynamic testing in the assessment of patients with upper quadrant disorders, is the response of the shoulder girdle. It is stated that a protective rising of the shoulder girdle is present when patients with neurogenic disorders are assessed and that the elevation is absent in asymptomatic subjects. As sensory responses are elicited in the majority of asymptomatic subjects and as the range of motion (ROM) is often limited during neurodynamic testing, it is questionable whether the elevation of the shoulder girdle would be absent in asymptomatic subjects. The aim of this study was to measure the shoulder girdle elevation force during five variants of the neural tissue provocation test for the median nerve. Thirty-five asymptomatic male subjects were assessed. A load cell was used to measure the amount of shoulder girdle elevation force and two electrogoniometers were used to measure the ROM at the elbow and wrist. When the ROM at the end of the test was restricted, a gradual increase in shoulder girdle elevation force could be observed throughout the test. Compared to the initial force at the start of the test, all variants resulted in a significant increase in force. It is concluded that a gradual increase in shoulder girdle elevation force should not be regarded as an abnormal sign in the interpretation of neurodynamic tests.

  18. Prediction of medial and lateral contact force of the knee joint during normal and turning gait after total knee replacement.

    PubMed

    Purevsuren, Tserenchimed; Dorj, Ariunzaya; Kim, Kyungsoo; Kim, Yoon Hyuk

    2016-04-01

    The computational modeling approach has commonly been used to predict knee joint contact forces, muscle forces, and ligament loads during activities of daily living. Knowledge of these forces has several potential applications, for example, within design of equipment to protect the knee joint from injury and to plan adequate rehabilitation protocols, although clinical applications of computational models are still evolving and one of the limiting factors is model validation. The objective of this study was to extend previous modeling technique and to improve the validity of the model prediction using publicly available data set of the fifth "Grand Challenge Competition to Predict In Vivo Knee Loads." A two-stage modeling approach, which combines conventional inverse dynamic analysis (the first stage) with a multi-body subject-specific lower limb model (the second stage), was used to calculate medial and lateral compartment contact forces. The validation was performed by direct comparison of model predictions and experimental measurement of medial and lateral compartment contact forces during normal and turning gait. The model predictions of both medial and lateral contact forces showed strong correlations with experimental measurements in normal gait (r = 0.75 and 0.71) and in turning gait trials (r = 0.86 and 0.72), even though the current technique over-estimated medial compartment contact forces in swing phase. The correlation coefficient, Sprague and Geers metrics, and root mean squared error indicated that the lateral contact forces were predicted better than medial contact forces in comparison with the experimental measurements during both normal and turning gait trials.

  19. Milwaukee shoulder syndrome.

    PubMed

    Nadarajah, Channa Vasanth; Weichert, Immo

    2014-01-01

    Milwaukee shoulder syndrome (MSS) is a rare destructive, calcium phosphate crystalline arthropathy. It encompasses an effusion that is noninflammatory with numerous aggregates of calcium hydroxyapatite crystals in the synovial fluid, associated with rotator cuff defects. We describe a patient that presented with recurrent shoulder pain and swelling with characteristic radiographic changes and MSS was confirmed on aspiration of the synovial fluid.

  20. Glenohumeral contact force during flat and topspin tennis forehand drives.

    PubMed

    Blache, Yoann; Creveaux, Thomas; Dumas, Raphaël; Chèze, Laurence; Rogowski, Isabelle

    2017-03-01

    The primary role of the shoulder joint in tennis forehand drive is at the expense of the loadings undergone by this joint. Nevertheless, few studies investigated glenohumeral (GH) contact forces during forehand drives. The aim of this study was to investigate GH compressive and shearing forces during the flat and topspin forehand drives in advanced tennis players. 3D kinematics of flat and topspin forehand drives of 11 advanced tennis players were recorded. The Delft Shoulder and Elbow musculoskeletal model was implemented to assess the magnitude and orientation of GH contact forces during the forehand drives. The results showed no differences in magnitude and orientation of GH contact forces between the flat and topspin forehand drives. The estimated maximal GH contact force during the forward swing phase was 3573 ± 1383 N, which was on average 1.25 times greater than during the follow-through phase, and 5.8 times greater than during the backswing phase. Regardless the phase of the forehand drive, GH contact forces pointed towards the anterior-superior part of the glenoid therefore standing for shearing forces. Knowledge of GH contact forces during real sport tasks performed at high velocity may improve the understanding of various sport-specific adaptations and causative factors for shoulder problems.

  1. Periprosthetic Shoulder Infection

    PubMed Central

    Franceschini, Vincenzo; Chillemi, Claudio

    2013-01-01

    Shoulder arthroplasty is considered the most effective surgical procedure for endstage shoulder pain from different causes including osteoarthritis, cuff-tear arthropathy, trauma, and tumors. Although uncommon and less frequent than knee or hip periprosthetic infection, periprosthetic shoulder infection represents a devastating complication and, despite treatment, is associated with unsatisfactory results. The most commonly identified microorganisms in periprosthetic shoulder infections are Staphylococcus aureus, coagulase-negative Staphylococci and Propionibacterium acnes. Diagnosis is not always easy and mainly derives from the integration of clinical symptoms, laboratory exams, radiological studies and microbiological swabs. Different options are available for treatment, including antibiotic therapy, lavage and debridement with retention of the prosthesis, one-stage reimplantation, two-stage reimplantation with antibiotic-impregnated cement spacer and resection arthroplasty. The aim of this review is to describe the current knowledge regarding risk factors, etiology, diagnosis and treatment of periprosthetic shoulder infection. PMID:23919098

  2. Integration of marker and force data to compute three-dimensional joint moments of the thumb and index finger digits during pinch

    PubMed Central

    Nataraj, Raviraj; Li, Zong-Ming

    2014-01-01

    This study presents methodology to determine joint moments of the digits of the hand during pinch function. This methodology incorporates steps to identify marker-based kinematic data defining aligned coordinate systems for individual digit segments and joint center locations. The kinematic data are then transformed to a common reference frame along with the force data collected at pinch contact of a customized apparatus in three-dimensions (3-D). These methods were demonstrated with a pilot investigation to examine the static joint moments occurring during two-digit oppositional precision pinch at a particular endpoint force level applied at the digit pads. Notable abduction joint moments at the proximal joints of both digits were observed, which implicate the role of respective intrinsic and extrinsic muscles in maintaining pinch grasp. Examining differences in joint moment results when substituting select steps of this methodological approach suggested greater relative importance for joint center identification and segment coordinate system alignment. PMID:23947659

  3. Physical examination of the overhead athlete's shoulder.

    PubMed

    Sewick, Amy; Kelly, John D; Rubin, Ben

    2012-03-01

    Overhead athletes seek the services of an orthopedic surgeon because of pain and/or dysfunction. It is important to address the cause of the symptoms more so than the source of the patient's pain, so that treatment will eliminate the problem rather than merely ameliorate symptoms temporarily. In order to accomplish a thorough assessment of shoulder function, the examiner must expand his/her view from isolated assessment of the glenohumeral joint range of motion, stability, assessment of rotator cuff strength, palpation and provocative maneuvers, and add assessment of the shoulder in the context of the kinetic chain. The examination of the thrower's shoulder, coupled with a thorough history, will usually provide a solid functional diagnosis and provide a good idea as to the presence of structural damage. As a result, the value of rehabilitation and the benefit of surgical intervention are made more predictable.

  4. [Triple fracture of the shoulder suspensory complex].

    PubMed

    Tamimi Mariño, I; Martin Rodríguez, I; Mora Villadeamigo, J

    2013-01-01

    The superior suspensory complex of the shoulder (SSCS) is a ring shaped structure composed of bones and soft tissues that play a fundamental role in the stability of the shoulder joint. Isolated injuries of the SSCS are relatively common, but injuries that affect 3 components are extremely unusual. We present a triple injury of the SSCS in a 26 year old patient with a Neer type ii clavicular fracture, a Kuhn type iii acromion fracture and an Ogawa type i coracoid fracture. An open reduction and stabilization of the clavicle was performed with 2 Kirschner nails. The acromial fracture was synthesized with 2 cannulated screws, and the coracoid fracture was treated conservatively. After 24 months of follow up the patient had an excellent functional outcome according to the Constat-Murley shoulder score and QuickDASH scoring system, and all the fractures healed correctly.

  5. Fusion angle affects intervertebral adjacent spinal segment joint forces-Model-based analysis of patient specific alignment.

    PubMed

    Senteler, Marco; Weisse, Bernhard; Rothenfluh, Dominique A; Farshad, Mazda T; Snedeker, Jess G

    2017-01-01

    This study addresses the hypothesis that adjacent segment intervertebral joint loads are sensitive to the degree of lordosis that is surgically imposed during vertebral fusion. Adjacent segment degeneration is often observed after lumbar fusion, but a causative mechanism is not yet clearly evident. Altered kinematics of the adjacent segments and potentially nonphysiological mechanical joint loads have been implicated in this process. However, little is known of how altered alignment and kinematics influence loading of the adjacent intervertebral joints under consideration of active muscle forces. This study investigated these effects by simulating L4/5 fusions using kinematics-driven musculoskeletal models of one generic and eight sagittal alignment-specific models. Models featured different spinopelvic configurations but were normalized by body height, masses, and muscle properties. Fusion of the L4/5 segment was implemented in an in situ (22°), hyperlordotic (32°), and hypolordotic (8°) fashion and kinematic input parameters were changed accordingly based on findings of an in vitro investigation. Bending motion from upright standing to 45° forward flexion and back was simulated for all models in intact and fused conditions. Joint loads at adjacent levels and moment arms of spinal muscles experienced changes after all types of fusion. Hypolordotic configuration led to an increase of adjacent segment (L3/4) shear forces of 29% on average, whereas hyperlordotic fusion reduced shear by 39%. Overall, L4/5 in situ fusion resulted in intervertebral joint forces closest to intact loading conditions. An artificial decrease in lumbar lordosis (minus 14° on average) caused by an L4/5 fusion lead to adverse loading conditions, particularly at the cranial adjacent levels, and altered muscle moment arms, in particular for muscles in the vicinity of the fusion. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:131-139, 2017.

  6. Achieving Cross-Domain Synergy: Overcoming Service Barriers to Joint Force 2020

    DTIC Science & Technology

    2014-06-13

    Davis, Mr. Russ Crumrine, and Mr. Kevin Gentzler for their continued support during this lengthy process . Your prompt feedback and excellent guidance...and guiding me every step of the way. I know that this process has helped me to see the big picture and has developed my understanding of military...Component Commander JOAC Joint Operational Access Concept JOPP Joint Operational Planning Process JOPPA Joint Operational Planning Process Air

  7. Effect of lateral meniscus allograft on shoulder articular contact areas and pressures.

    PubMed

    Creighton, R Alexander; Cole, Brian J; Nicholson, Gregory P; Romeo, Anthony A; Lorenz, Eric P

    2007-01-01

    The objective of this study was to determine the effect of a lateral meniscus allograft on the articular contact area and pressures across the glenohumeral joint under compressive loads of 220 N and 440 N. Eight fresh-frozen shoulders were used, and contact areas and pressures were determined with a Tekscan flexible tactile force sensor. Testing conditions included a normal glenohumeral joint and one interposed with a lateral meniscus allograft. Using the Tekscan sensing equipment, we evaluated the total force (in Newtons), contact area (in square millimeters), mean contact pressure (in kilograms per square centimeter), peak force (in Newtons), and peak contact pressure (in kilograms per square centimeter). The interposed lateral meniscus allograft group showed a statistically significant decrease in total force at both 220 N and 440 N, as well as a decrease in contact area for the 220-N testing condition. There were no statistically significant differences between the two groups in contact area at 440 N or in peak forces or peak contact areas for either 220-N or 440-N testing condition. Biomechanically biologic resurfacing with a lateral meniscus allograft of the glenohumeral joint is supported by decreased forces on the glenoid surface.

  8. Infliximab partially alleviates the bite force reduction in a mouse model of temporomandibular joint pain.

    PubMed

    Kim, Sang-Hyon; Son, Chang-Nam; Lee, Hyo-Jung; Cho, Ho-Chan; Jung, Sung-Won; Hur, Ji An; Baek, Won-Ki; Jung, Hye Ra; Hong, Ji Hee

    2015-05-01

    Temporomandibular joint (TMJ) disorder is clinically important because of its prevalence, chronicity, and therapy-refractoriness of the pain. In this study, we investigated the effect of infliximab in a mouse model of TMJ pain using a specially-engineered transducer for evaluating the changes in bite force (BF). The mice were randomly divided into three groups (7 mice per group): the control group, the complete Freund's adjuvant (CFA) group, and the infliximab group. BF was measured at day 0 (baseline BF). After measuring the baseline BF, CFA or incomplete Freund's adjuvant was injected into both TMJs and then the changes in BF were measured at days 1, 3, 5, 7, 9, and 13 after the TMJ injection. For measuring the BF, we used a custom-built BF transducer. Control, CFA, and infliximab groups showed similar baseline BF at day 0. From day 1, a significant reduction in BF was observed in the CFA group, and this reduction in BF was statistically significant compared to that in the control group (P < 0.05). This reduction in BF was maintained until day 7, and BF started to recover gradually from day 9. In the infliximab group also, the reduction in BF was observed on day 1, and this reduction was maintained until day 7. However, the degree of reduction in BF was less remarkable compared to that in the CFA group. The reduction in BF caused by injection of CFA into the TMJ could be partially alleviated by the injection of anti-tumor necrosis factor alpha, infliximab.

  9. Effect of stretching on agonist-antagonist muscle activity and muscle force output during single and multiple joint isometric contractions.

    PubMed

    McBride, J M; Deane, R; Nimphius, S

    2007-02-01

    Eight moderately active male subjects where tested for peak force in an isometric knee extension test and peak force and rate of force development in an isometric squat test. Both tests where performed at a 100 degrees knee angle and average integrated electromyography (IEMG) was measured from the vastus medialis (VM), vastus lateralis (VL) and biceps femoris (BF) muscles. Subjects performed the two conditions, stretching (S) or control (C) in a randomized order. Subjects where tested for baseline strength measures in both the isometric knee extension and isometric squat and then either stretched or sat quietly for 10 min. Following S or C subjects where then tested at six time points. Following S peak force in the isometric knee extension was significantly (P < or = 0.05) less than C at 1, 2, 8 and 16 min post. No significant difference in peak force was found between S and C in the isometric squat. However, following S the rate of force development in the isometric squat was significantly less than C at immediately post. No significant differences where observed in IEMG of the VM or VL between S and C in either the isometric knee extension or isometric squat. However, IEMG significantly decreased in the BF at 1 min post after S in comparison with C in both the isometric knee extension and isometric squat. Stretching appears to decrease muscle force output in a single joint isometric contraction and rate of force development in a multiple joint isometric contraction. Possible changes in agonist-antagonist muscle activity patterns need to be further examined.

  10. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running

    PubMed Central

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running. PMID:28234946

  11. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running.

    PubMed

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running.

  12. CURRENT CONCEPTS IN SHOULDER EXAMINATION OF THE OVERHEAD ATHLETE

    PubMed Central

    Ellenbecker, Todd

    2013-01-01

    Examination of the shoulder complex has long been described as challenging. This is particularly true in the examination of the overhead athlete who has structural differences when compared to a shoulder patient who is a non‐athlete. Complexity with the examination is due to unique biomechanical and structural changes, multiple joint articulations, multiple pain patterns, and the potential of injury to structures both inside (intra‐articular) and outside (extra‐articular) the glenohumeral joint. Repetitive stresses placed on the shoulders of overhead athletes may affect range of motion, strength, scapular position, and ultimately, the integrity of soft tissue and bony structures in any of the joints that comprise the shoulder complex. Furthermore, many shoulder examination tests thought to be unique to a single structure, joint, or condition can be positive in multiple conditions. The examination of the overhead athletes shoulder, coupled with a thorough medical history will provide a solid foundation to allow a functional physical therapy diagnosis and provide clues as to the presence of the lesion (s) causing disability. The purpose of this clinical commentary is to assist the reader to understand the unique physical characteristics of the overhead athlete, which will lead to a more accurate and reproducible evaluation of athletes who sustain injuries while participating in overhead sports. Level of Evidence: 5 PMID:24175138

  13. Proprioception and Throwing Accuracy in the Dominant Shoulder After Cryotherapy

    PubMed Central

    Wassinger, Craig A; Myers, Joseph B; Gatti, Joseph M; Conley, Kevin M; Lephart, Scott M

    2007-01-01

    Context: Application of cryotherapy modalities is common after acute shoulder injury and as part of rehabilitation. During athletic events, athletes may return to play after this treatment. The effects of cryotherapy on dominant shoulder proprioception have been assessed, yet the effects on throwing performance are unknown. Objective: To determine the effects of a cryotherapy application on shoulder proprioception and throwing accuracy. Design: Single-group, pretest-posttest control session design. Setting: University-based biomechanics laboratory. Patients or Other Participants: Healthy college-aged subjects (n = 22). Intervention(s): Twenty-minute ice pack application to the dominant shoulder. Main Outcome Measure(s): Active joint position replication, path of joint motion replication, and the Functional Throwing Performance Index. Results: Subjects demonstrated significant increases in deviation for path of joint motion replication when moving from 90° of abduction with 90° of external rotation to 20° of flexion with neutral shoulder rotation after ice pack application. Also, subjects exhibited a decrease in Functional Throwing Performance Index after cryotherapy application. No differences were found in subjects for active joint position replication after cryotherapy application. Conclusions: Proprioception and throwing accuracy were decreased after ice pack application to the shoulder. It is important that clinicians understand the deficits that occur after cryotherapy, as this modality is commonly used following acute injury and during rehabilitation. This information should also be considered when attempting to return an athlete to play after treatment. PMID:17597948

  14. Biomechanics of Reverse Shoulder Arthroplasty: 
Current Concepts.

    PubMed

    Lorenzetti, Adam J; Stone, Geoffrey P; Simon, Peter; Frankle, Mark A

    2016-01-01

    The evolution of reverse shoulder arthroplasty has provided surgeons with new solutions for many complex shoulder problems. A primary goal of orthopaedics is the restoration or re-creation of functional anatomy to reduce pain and improve function, which can be accomplished by either repairing injured structures or replacing them as anatomically as possible. If reconstructible tissue is lacking or not available, which is seen in patients who have complex shoulder conditions such as an irreparable rotator cuff-deficient shoulder, cuff tear arthropathy, or severe glenoid bone loss, substantial problems may arise. Historically, hemiarthroplasty or glenoid grafting with total shoulder arthroplasty yielded inconsistent and unsatisfactory results. Underlying pathologies in patients who have an irreparable rotator cuff-deficient shoulder, cuff tear arthropathy, or severe glenoid bone loss can considerably alter the mechanical function of the shoulder and create treatment dilemmas that are difficult to overcome. A better biomechanical understanding of these pathologic adaptations has improved treatment options. In the past three decades, reverse total shoulder arthroplasty was developed to treat these complex shoulder conditions not by specifically re-creating the anatomy but by using the remaining functional tissue to improve shoulder balance. Reverse total shoulder arthroplasty has achieved reliable improvements in both pain and function. Initial implant designs lacked scientific evidence to support the design rationale, and many implants failed because surgeons did not completely understand the forces involved or the pathology being treated. Implant function and clinical results will continue to improve as surgeons' biomechanical understanding of shoulder disease and reverse shoulder arthroplasty implants increases.

  15. Functional outcomes assessment in shoulder surgery

    PubMed Central

    Wylie, James D; Beckmann, James T; Granger, Erin; Tashjian, Robert Z

    2014-01-01

    The effective evaluation and management of orthopaedic conditions including shoulder disorders relies upon understanding the level of disability created by the disease process. Validated outcome measures are critical to the evaluation process. Traditionally, outcome measures have been physician derived objective evaluations including range of motion and radiologic evaluations. However, these measures can marginalize a patient’s perception of their disability or outcome. As a result of these limitations, patient self-reported outcomes measures have become popular over the last quarter century and are currently primary tools to evaluate outcomes of treatment. Patient reported outcomes measures can be general health related quality of life measures, health utility measures, region specific health related quality of life measures or condition specific measures. Several patients self-reported outcomes measures have been developed and validated for evaluating patients with shoulder disorders. Computer adaptive testing will likely play an important role in the arsenal of measures used to evaluate shoulder patients in the future. The purpose of this article is to review the general health related quality-of-life measures as well as the joint-specific and condition specific measures utilized in evaluating patients with shoulder conditions. Advances in computer adaptive testing as it relates to assessing dysfunction in shoulder conditions will also be reviewed. PMID:25405091

  16. The evaluation of the failed shoulder arthroplasty.

    PubMed

    Wiater, Brett P; Moravek, James E; Wiater, J Michael

    2014-05-01

    As the incidence of shoulder arthroplasty continues to rise, the orthopedic shoulder surgeon will be increasingly faced with the difficult problem of evaluating a failed shoulder arthroplasty. The patient is usually dissatisfied with the outcome of the previous arthroplasty as a result of pain, but may complain of poor function due to limited range of motion or instability. A thorough and systematic approach is necessary so that the most appropriate treatment pathway can be initiated. A comprehensive history and physical examination are the first steps in the evaluation. Diagnostic studies are numerous and include laboratory values, plain radiography, computed tomography, ultrasound imaging, joint aspiration, nuclear scans, and electromyography. Common causes of early pain after shoulder arthroplasty include technical issues related to the surgery, such as malposition or improper sizing of the prosthesis, periprosthetic infection, neurologic injury, and complex regional pain syndrome. Pain presenting after a symptom-free interval may be related to chronic periprosthetic infection, component wear and loosening, glenoid erosion, rotator cuff degeneration, and fracture. Poor range of motion may result from inadequate postoperative rehabilitation, implant-related factors, and heterotopic ossification. Instability is generally caused by rotator cuff deficiency and implant-related factors. Unfortunately, determining the cause of a failed shoulder arthroplasty can be difficult, and in many situations, the source of pain and disability is multifactorial.

  17. Occupational therapy interventions for shoulder conditions: a systematic review.

    PubMed

    von der Heyde, Rebecca L

    2011-01-01

    The objectives of this systematic review were (1) to identify, evaluate, and synthesize the research literature of relevance to occupational therapy regarding interventions for work-related shoulder conditions and (2) to interpret and apply the research literature to occupational therapy. Twenty-two studies were reviewed for this study-16 of Level I evidence, 2 of Level II evidence, and 4 of Level III evidence. In this systematic review, limited evidence from Level I studies was found to support exercise for shoulder pain; manual therapy and laser for adhesive capsulitis; conservative management of shoulder instability; early intervention without immobilization for specific, nondisplaced proximal humerus fractures; and exercise, joint mobilizations, and laser for patients with shoulder impingement. Further prospective studies are necessary for the delineation of specific surgical and therapeutic variables that facilitate positive outcomes in the treatment of patients with shoulder conditions.

  18. Application of computational lower extremity model to investigate different muscle activities and joint force patterns in knee osteoarthritis patients during walking.

    PubMed

    Nha, Kyung Wook; Dorj, Ariunzaya; Feng, Jun; Shin, Jun Ho; Kim, Jong In; Kwon, Jae Ho; Kim, Kyungsoo; Kim, Yoon Hyuk

    2013-01-01

    Many experimental and computational studies have reported that osteoarthritis in the knee joint affects knee biomechanics, including joint kinematics, joint contact forces, and muscle activities, due to functional restriction and disability. In this study, differences in muscle activities and joint force patterns between knee osteoarthritis (OA) patients and normal subjects during walking were investigated using the inverse dynamic analysis with a lower extremity musculoskeletal model. Extensor/flexor muscle activations and torque ratios and the joint contact forces were compared between the OA and normal groups. The OA patients had higher extensor muscle forces and lateral component of the knee joint force than normal subjects as well as force and torque ratios of extensor and flexor muscles, while the other parameters had little differences. The results explained that OA patients increased the level of antagonistic cocontraction and the adduction moment on the knee joint. The presented findings and technologies provide insight into biomechanical changes in OA patients and can also be used to evaluate the postoperative functional outcomes of the OA treatments.

  19. Incorporation of lower neck shear forces to predict facet joint injury risk in low-speed automotive rear impacts.

    PubMed

    Stemper, Brian D; Storvik, Steven G

    2010-06-01

    Lower neck shear force remains a viable candidate for a low-velocity automotive rear-impact injury criterion. Data were previously reported to demonstrate high correlations between the magnitude of lower neck shear force and lower cervical spine facet joint motions. The present study determined the ability of lower neck shear force to predict soft-tissue injury risk in simulated automotive rear impacts. Rear-impact tests were conducted at two velocities and with two seatback orientations using a Hybrid III anthropomorphic test device (ATD) and stock automobile seats from 2007 model year vehicles. Higher velocities and more vertical seatback orientations were associated with higher injury risk based on computational modeling simulations performed in this study. Six cervical spine injury criteria including NIC, Nij, Nkm, LNL, and lower neck shear force and bending moment, increased with impact velocity. NIC, Nij, and shear force were most sensitive to changes in impact velocity. Four metrics, including Nkm, LNL, and lower neck shear force and bending moment, increased for tests with more vertical seatback orientations. Shear force was most sensitive to changes in seatback orientation. Peak values for shear force, NIC, and Nij occurred approximately at the time of head restraint contact for all four test conditions. Therefore, of the six investigated metrics, lower neck shear force was the only metric to demonstrate consistency with regard to injury risk and timing of peak magnitudes. These results demonstrate the ability of lower neck shear force to predict injury risk during low velocity automotive rear impacts and warrant continued investigation into the sensitivity and applicability of this metric for other rear-impact conditions.

  20. The effects of finger extension on shoulder muscle activity

    PubMed Central

    Yi, Chae-Woo; Shin, Ju-Yong; Kim, Youn-Joung

    2015-01-01

    [Purpose] This study aims to examine the effects of the extension of the fingers (distal upper limb) on the activity of the shoulder muscles (proximal upper limb). [Subjects and Methods] This study involved 14 healthy male adults with no musculoskeletal disorder or pain related to the shoulders and hands. The subjects in a sitting posture abducted the angle of the shoulder joints at 60° and had their palms in the front direction. Electromyography (EMG) was comparatively analyzed to look at the activities of the infraspinatus (IS) and rhomboid major (RM) when the fingers were extended and relaxed. [Results] The activity of the IS was statistically significantly higher when the fingers were extended than when they were relaxed. [Conclusion] According to the result of this study, finger extension is considered to affect the muscles for connected shoulder joint stability. PMID:26504277

  1. Expertise-dependent modulation of muscular and non-muscular torques in multi-joint arm movements during piano keystroke.

    PubMed

    Furuya, S; Kinoshita, H

    2008-10-02

    The problem of skill-level-dependent modulation in the joint dynamics of multi-joint arm movements is addressed in this study using piano keystroke performed by expert and novice piano players. Using the measured kinematic and key-force data, the time varying net, gravitational, motion-dependent interaction (INT), key-reaction (REA), and muscular (MUS) torques at the shoulder, elbow, wrist, and metacarpophalangeal (MP) joints were computed using inverse dynamics techniques. INTs generated at the elbow and wrist joints, but not those at the MP joint, were greater for the experts as compared with the novices. REA at the MP joint, but not at the other joints, was less for the experts as compared with the novices. The MUSs at the MP, wrist, and elbow joints were smaller, and that at the shoulder joint was larger for the experts as compared with the novices. The experts also had a lesser inter-strike variability of key striking force and key descending velocity as compared with the novices. These findings indicated that the relationship among the INT, REA, and MUS occurring at the joints of the upper-extremity differed between the expert and novice piano players, suggesting that the organization of multi-joint arm movement is modulated by long-term motor training toward facilitating both physiological efficiency and movement accuracy.

  2. Pathology of Gray Wolf Shoulders: Lessons in Species and Aging.

    PubMed

    Lawler, Dennis; Becker, Julia; Reetz, Jennifer; Goodmann, Pat; Evans, Richard; Rubin, David; Tangredi, Basil; Widga, Christopher; Sackman, Jill; Martin, Terrence; Kohn, Luci; Smith, Gail

    2016-10-01

    We examined scapula glenoids (n = 14) and proximal articular humeri (n = 14) of seven gray wolves that were maintained in a sanctuary park setting. Immediately after death, observations were made visually in situ and by radiography. Further observations were made in a museum laboratory setting, prior to and following clearing of soft tissues. Selected dry bone specimens were evaluated using computed tomography. Significant cartilage erosion and osteoarthropathy were identified in all shoulder joints. No single evaluation method yielded maximal information. Plain film radiography revealed only more severe changes. Computed tomography yielded more detail and clarity than standard radiography. Direct examination of articular cartilage informed about joint soft tissue, and dry bone informed about externally visible bone pathology. These data provide a basis for biological, biomedical, ecological, and archaeological scientists to improve retrospective interpretations of bone lesions. They further support developing plausible differential diagnoses for features of ancient and modern animal bones. We noted a dog-like capacity for wolf longevity in a non-free-roaming environment. However, aged wolves' life spans far exceeded those of similar-sized domestic dogs and breeds, suggesting the possibility of an important species difference that should be explored. We suggest also a hypothesis that the driving force for joint pathology in sheltered non-domestic species may relate significantly to achieving the longevity that is possible biologically, but is uncommon in the wild because of differential stochastic influences. Anat Rec, 299:1338-1347, 2016. © 2016 Wiley Periodicals, Inc.

  3. The senses of active and passive forces at the human ankle joint.

    PubMed

    Savage, G; Allen, T J; Proske, U

    2015-07-01

    The traditional view of the neural basis for the sense of muscle force is that it is generated at least in part within the brain. Recently it has been proposed that force sensations do not arise entirely centrally and that there is a contribution from peripheral receptors within the contracting muscle. Evidence comes from experiments on thumb flexor and elbow flexor muscles. Here we have studied the sense of force in plantar flexor muscles of the human ankle, looking for further evidence for such a mechanism. The active angle-torque curve was measured for muscles of both legs, and for each muscle, ankle angles were identified on the ascending and descending limbs of the curve where active forces were similar. In a plantar flexion force matching task, subjects were asked to match the force in one foot, generated on the ascending limb of the curve, with force in the other foot, generated on the descending limb. It was hypothesised that despite active forces being similar, the sensation generated in the more stretched muscle should be greater because of the contribution from its peripheral stretch receptors, leading to an overestimation of the force in the stretched muscle. It was found that provided that the comparison was between active forces, there was no difference in the forces generated by the two legs, supporting the central hypothesis for the sense of force. When total forces were matched, including a component of passive force due to muscle stretch, subjects seemed to ignore the passive component. Yet subjects had an acute sense of passive force, provided that the muscles remained relaxed. It was concluded that subjects had two senses, a sense of active force, generated centrally, and a sense of passive force, or perhaps muscle stretch, generated within the muscle itself.

  4. Pharmacy Faculty Workplace Issues: Findings From the 2009-2010 COD-COF Joint Task Force on Faculty Workforce

    PubMed Central

    Peirce, Gretchen L.; Crabtree, Brian L.; Acosta, Daniel; Early, Johnnie L.; Kishi, Donald T.; Nobles-Knight, Dolores; Webster, Andrew A.

    2011-01-01

    Many factors contribute to the vitality of an individual faculty member, a department, and an entire academic organization. Some of the relationships among these factors are well understood, but many questions remain unanswered. The Joint Task Force on Faculty Workforce examined the literature on faculty workforce issues, including the work of previous task forces charged by the American Association of Colleges of Pharmacy (AACP). We identified and focused on 4 unique but interrelated concepts: organizational culture/climate, role of the department chair, faculty recruitment and retention, and mentoring. Among all 4 resides the need to consider issues of intergenerational, intercultural, and gender dynamics. This paper reports the findings of the task force and proffers specific recommendations to AACP and to colleges and schools of pharmacy. PMID:21769139

  5. [Tendon ruptures of the shoulder].

    PubMed

    Habermeyer, P

    1989-08-01

    Common sports, involving raising the arms above the head, i.e., throwing, racquet games and swimming, often result in rotator cuff tendinitis. During the throwing motion, the humeral head and its overlying biceps tendon and rotator cuff must pass rapidly under the coraco-acromial arch. Damage to these structures can occur by several mechanism. First, an increase in the size of the structures passing underneath the arch may lead to impingement. This can occur either by way of hypertrophy of the musculotendinous cuff or by way of inflammation of the cuff. Second, a decreased space available underneath the arch secondary to osteophyte formation of the acromion and fibrosis of the subacromial space may lead to impingement. Third, weakness or incompetence of the rotator cuff allows the humerus to ride up and impinge on the coracoacromial arch with motion of the shoulder. Tendinitis can be combined with increased laxity of the glenohumeral joint and/or acquired instability due to a labral tear. Prevention of overuse injuries is a cornerstone of our treatment concept. The muscle tendon unit requires passive and neuromuscular facilitated streching after warming-up exercises. Muscular imbalance and weakness are prevented by balanced eccentric strenthening with particular attention to the external rotators and scapular muscles. Knowledge of the mechanics of the pitching motion, tennis serve, swimming stroke, etc. is of paramount importance in the prevention of injuries. As the onset of shoulder problems contributes to a particularly fatiguing situation, extreme fatique performance severity should be avoided. Every effort must be made to apply conservative treatment when overuse problems arise in the athlete's shoulder.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Joint Interdiction

    DTIC Science & Technology

    2016-09-09

    Purpose This publication has been prepared under the direction of the Chairman of the Joint Chiefs of Staff. It sets forth joint doctrine to govern the...governmental and nongovernmental organizations, multinational forces, and other interorganizational partners. It provides military guidance for the...exercise of authority by combatant commanders and other joint force commanders (JFCs), and prescribes joint doctrine for operations and training. It

  7. Shoulder MRI scan

    MedlinePlus

    ... an imaging test that uses energy from powerful magnets and to create pictures of the shoulder area. ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed in the room ...

  8. SHOULDER ARTHROPLASTY RECORDS

    PubMed Central

    Filho, Geraldo Motta; Galvão, Marcus Vinicius; Monteiro, Martim; Cohen, Marcio; Brandão, Bruno

    2015-01-01

    The study's objective is to evaluate the characteristics and problems of patients who underwent shoulder arthroplasties between July 2004 and November 2006. Methodology: During the period of the study, 145 shoulder arthroplasties were performed. A prospective protocol was used for every patient; demographic, clinical and surgical procedure data were collected. All gathered data were included in the data base. The patients were divided in three major groups: fractures, degenerative diseases and trauma sequels. Information obtained from the data base was correlated in order to determine patients' epidemiologic, injuries, and surgical procedure profiles. Results: Of the 145 shoulder arthroplasties performed, 37% presented trauma sequels, 30% degenerative diseases, and 33% proximal humerus fracture. 12% of the cases required total arthroplasties and 88% partial arthroplasties. Five major complications were observed on early postoperative period. Conclusion: Shoulder arthroplasties have become a common procedure in orthopaedic practice. Surgical records are important in evidencing progressive evolution and in enabling future clinical outcomes evaluation. PMID:26998463

  9. Ultrasound-guided interventional procedures around the shoulder.

    PubMed

    Messina, Carmelo; Banfi, Giuseppe; Orlandi, Davide; Lacelli, Francesca; Serafini, Giovanni; Mauri, Giovanni; Secchi, Francesco; Silvestri, Enzo; Sconfienza, Luca Maria

    2016-01-01

    Ultrasound is an established modality for shoulder evaluation, being accurate, low cost and radiation free. Different pathological conditions can be diagnosed using ultrasound and can be treated using ultrasound guidance, such as degenerative, traumatic or inflammatory diseases. Subacromial-subdeltoid bursitis is the most common finding on ultrasound evaluation for painful shoulder. Therapeutic injections of corticosteroids are helpful to reduce inflammation and pain. Calcific tendinopathy of rotator cuff affects up to 20% of painful shoulders. Ultrasound-guided treatment may be performed with both single- and double-needle approach. Calcific enthesopathy, a peculiar form of degenerative tendinopathy, is a common and mostly asymptomatic ultrasound finding; dry needling has been proposed in symptomatic patients. An alternative is represented by autologous platelet-rich plasma injections. Intra-articular injections of the shoulder can be performed in the treatment of a variety of inflammatory and degenerative diseases with corticosteroids or hyaluronic acid respectively. Steroid injections around the long head of the biceps brachii tendon are indicated in patients with biceps tendinopathy, reducing pain and humeral tenderness. The most common indication for acromion-clavicular joint injection is degenerative osteoarthritis, with ultrasound representing a useful tool in localizing the joint space and properly injecting various types of drugs (steroids, lidocaine or hyaluronic acid). Suprascapular nerve block is an approved treatment for chronic shoulder pain non-responsive to conventional treatments as well as candidate patients for shoulder arthroscopy. This review provides an overview of these different ultrasonography-guided procedures that can be performed around the shoulder.

  10. U.S. Joint Special Operations Forces: Two Few, Overworked, Young, Homogenous & Macho to Fulfill the Unconventional Demands of the Long War?

    DTIC Science & Technology

    2008-05-28

    OVERWORKED, YOUNG, HOMOGENOUS, & MACHO TO FULFILL THE UNCONVENTIONAL DEMANDS OF THE LONG WAR? SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR...U.S. Joint Special Operations Forces: Two Few, Overworked, Young, Homogenous & Macho to Fulfill the Unconventional Demands of the Long War? 5a...Executive Summary Title: U.S. Joint Special Operations Forces: Too Few, Overworked, Young, Homogenous, & Macho to Fulfill the Unconventional

  11. Kinetic chain abnormalities in the athletic shoulder.

    PubMed

    Sciascia, Aaron; Thigpen, Charles; Namdari, Surena; Baldwin, Keith

    2012-03-01

    Overhead activities require the shoulder to be exposed to and sustain repetitive loads. The segmental activation of the body's links, known as the kinetic chain, allows this to occur effectively. Proper muscle activation is achieved through generation of energy from the central segment or core, which then transfers the energy to the terminal links of the shoulder, elbow, and hand. The kinetic chain is best characterized by 3 components: optimized anatomy, reproducible efficient motor patterns, and the sequential generation of forces. However, tissue injury and anatomic deficits such as weakness and/or tightness in the leg, pelvic core, or scapular musculature can lead to overuse shoulder injuries. These injuries can be prevented and maladaptations can be detected with a thorough understanding of biomechanics of the kinetic chain as it relates to overhead activity.

  12. Development of a Finite Element Model of the Human Shoulder to Investigate the Mechanical Responses and Injuries in Side Impact

    NASA Astrophysics Data System (ADS)

    Iwamoto, Masami; Miki, Kazuo; Yang, King H.

    Previous studies in both fields of automotive safety and orthopedic surgery have hypothesized that immobilization of the shoulder caused by the shoulder injury could be related to multiple rib fractures, which are frequently life threatening. Therefore, for more effective occupant protection, it is important to understand the relationship between shoulder injury and multiple rib fractures in side impact. The purpose of this study is to develop a finite element model of the human shoulder in order to understand this relationship. The shoulder model included three bones (the humerus, scapula and clavicle) and major ligaments and muscles around the shoulder. The model also included approaches to represent bone fractures and joint dislocations. The relationships between shoulder injury and immobilization of the shoulder are discussed using model responses for lateral shoulder impact. It is also discussed how the injury can be related to multiple rib fractures.

  13. Primary Frozen Shoulder Syndrome: Arthroscopic Capsular Release

    PubMed Central

    Arce, Guillermo

    2015-01-01

    Idiopathic adhesive capsulitis, or primary frozen shoulder syndrome, is a fairly common orthopaedic problem characterized by shoulder pain and loss of motion. In most cases, conservative treatment (6-month physical therapy program and intra-articular steroid injections) improves symptoms and restores shoulder motion. In refractory cases, arthroscopic capsular release is indicated. This surgical procedure carries several advantages over other treatment modalities. First, it provides precise and controlled release of the capsule and ligaments, reducing the risk of traumatic complications observed after forceful shoulder manipulation. Second, release of the capsule and the involved structures with a radiofrequency device delays healing, which prevents adhesion formation. Third, the technique is straightforward, and an oral postoperative steroid program decreases pain and allows for a pleasant early rehabilitation program. Fourth, the procedure is performed with the patient fully awake under an interscalene block, which boosts the patient's confidence and adherence to the physical therapy protocol. In patients with refractory primary frozen shoulder syndrome, arthroscopic capsular release emerges as a suitable option that leads to a faster and long-lasting recovery. PMID:26870652

  14. Shouldering the load, maximising value.

    PubMed

    Baillie, Jonathan

    2015-02-01

    In mid-November last year Ryhurst signed what it dubbed 'a ground-breaking strategic estates partnership' agreement with the Isle of Wight NHS Trust (HEJ - January 2015). Under the Wight Life Partnership, the two organisations will work in partnership 'to comprehensively review the estate across all the Trust's sites to ensure that buildings and grounds are being fully utilised, and suitable for modern healthcare'. This is Ryhurst's third such 'whole estate' joint-venture agreement with the NHS, and the first with a non-Foundation Trust, harnessing an approach that sees the company shoulder a considerable part of the burden of making optimum use of, and deriving 'maximum value' from, large healthcare estates. HEJ editor, Jonathan Baillie, reports.

  15. Security Force Assistance: Building Foreign Security Forces and Joint Doctrine for the Future of U.S. Regional Security

    DTIC Science & Technology

    2008-04-11

    care, economic development, environmental protection, human rights , and conflict resolution; and/or encouraging the establishment of democratic...that time along with its culture, family life , and position in Philippine society. There are many lessons learned from the U.S. Army’s experience in...excellent at training battalion size and below indigenous forces, are they the right choice to stand up a foreign armored division complete with

  16. ShouldeRO, an alignment-free two-DOF rehabilitation robot for the shoulder complex.

    PubMed

    Dehez, Bruno; Sapin, Julien

    2011-01-01

    This paper presents a robot aimed to assist the shoulder movements of stroke patients during their rehabilitation process. This robot has the general form of an exoskeleton, but is characterized by an action principle on the patient no longer requiring a tedious and accurate alignment of the robot and patient's joints. It is constituted of a poly-articulated structure whose actuation is deported and transmission is ensured by Bowden cables. It manages two of the three rotational degrees of freedom (DOFs) of the shoulder. Quite light and compact, its proximal end can be rigidly fixed to the patient's back on a rucksack structure. As for its distal end, it is connected to the arm through passive joints and a splint guaranteeing the robot action principle, i.e. exert a force perpendicular to the patient's arm, whatever its configuration. This paper also presents a first prototype of this robot and some experimental results such as the arm angular excursions reached with the robot in the three joint planes.

  17. Diagnosis and Management of Periprosthetic Shoulder Infections.

    PubMed

    Mook, William R; Garrigues, Grant E

    2014-06-04

    ➤ The unique bacterial flora of the shoulder present diagnostic and treatment challenges that are distinct from those seen with failed hip and knee arthroplasties.➤ The presentation, diagnosis, and management of suppurative periprosthetic joint infections of the shoulder are similar to those of the hip and the knee.➤ Failed arthroplasties with positive cultures (FAPCs) are poorly performing shoulder reconstructions associated with low-virulence microorganisms that do not evoke a suppurative inflammatory response. Propionibacterium acnes is the predominant bacterium isolated from these cases.➤ With improved surgeon awareness and the addition of longer tissue-culture incubation times, detection of FAPCs has become more common. However, management is hampered by the lack of reliable, timely tests that can determine the presence of less virulent organisms in the preoperative or intraoperative settings.➤ The implications of positive culture results in FAPCs are unclear. Key test characteristics such as the false-positive rate and the prevalence of positive cultures in well-performing shoulders are unknown as there is no useful confirmatory test to validate the culture data and no reliable way to detect the presence of less virulent microorganisms without reoperation.➤ Soft-tissue and osseous deficits are frequently encountered when revising previously infected shoulders. The rate of complications in these scenarios is high, and the outcomes are the least favorable compared with revisions for any other indication.➤ The development of a consensus definition of a periprosthetic shoulder infection is critical to future investigations of these devastating complications.

  18. Hypothyroidism: Does It Cause Joint Pain?

    MedlinePlus

    Hypothyroidism: Does it cause joint pain? Can hypothyroidism cause joint pain? I have hypothyroidism and have been experiencing severe arthritis-like pain in my shoulders and hips. Answers from Todd B. ...

  19. Psychophysical testing of visual prosthetic devices: a call to establish a multi-national joint task force

    NASA Astrophysics Data System (ADS)

    Rizzo, Joseph F., III; Ayton, Lauren N.

    2014-04-01

    Recent advances in the field of visual prostheses, as showcased in this special feature of Journal of Neural Engineering , have led to promising results from clinical trials of a number of devices. However, as noted by these groups there are many challenges involved in assessing vision of people with profound vision loss. As such, it is important that there is consistency in the methodology and reporting standards for clinical trials of visual prostheses and, indeed, the broader vision restoration research field. Two visual prosthesis research groups, the Boston Retinal Implant Project (BRIP) and Bionic Vision Australia (BVA), have agreed to work cooperatively to establish a multi-national Joint Task Force. The aim of this Task Force will be to develop a consensus statement to guide the methods used to conduct and report psychophysical and clinical results of humans who receive visual prosthetic devices. The overarching goal is to ensure maximum benefit to the implant recipients, not only in the outcomes of the visual prosthesis itself, but also in enabling them to obtain accurate information about this research with ease. The aspiration to develop a Joint Task Force was first promulgated at the inaugural 'The Eye and the Chip' meeting in September 2000. This meeting was established to promote the development of the visual prosthetic field by applying the principles of inclusiveness, openness, and collegiality among the growing body of researchers in this field. These same principles underlie the intent of this Joint Task Force to enhance the quality of psychophysical research within our community. Despite prior efforts, a critical mass of interested parties could not congeal. Renewed interest for developing joint guidelines has developed recently because of a growing awareness of the challenges of obtaining reliable measurements of visual function in patients who are severely visually impaired (in whom testing is inherently noisy), and of the importance of

  20. Computer-Mediated Training Tools to Enhance Joint Task Force Cognitive Leadership Skills

    DTIC Science & Technology

    2007-04-01

    this morning’s reports indicate that a significant concentration of al-Qaeda operatives and Taliban forces have been discovered once again in the Shahi ...assistance of a US-led JTF to deal with the resurgence of enemy forces in the Shahi -Kot Valley. Module #1 Scenario: (Strategic National Level) You are on the...to conduct Operation DIAMONDBACK to destroy al-Qaeda and Taliban forces in the vicinity of the Shahi -Kot Valley and Arma Mountains southeast of Zormat

  1. Active Vibration Control of a Large Flexible Manipulator by Inertial Force and Joint Torque. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lee, Soo Han

    1988-01-01

    The efficiency and positional accuracy of a lightweight flexible manipulator are limited by its flexural vibrations, which last after a gross motion is completed. The vibration delays subsequent operations. In the proposed work, the vibration is suppressed by inertial force of a small arm in addition to the joint actuators and passive damping treatment. The proposed approach is: (1) Dynamic modeling of a combined system, a large flexible manipulator and a small arm, (2) Determination of optimal sensor location and controller algorithm, and (3) Verification of the fitness of model and the performance of controller.

  2. Multiply By 10 - Divide By 9. Is Technology A Force Multiplier or Force Divider in Joint Combat Operations?

    DTIC Science & Technology

    2006-05-31

    preponderance of focus and attention should be on people since it is the human brain that is the subject and target of IW/IO.17 The digital warrior comes with...soldier from the task at hand.22 JFCs want more lethality and agility, and IT can support this, but the human brain can only process so much information...planning operations and employing forces are techno-fright, particularly among older baby -boomers, and the problem with great quantities of data missing

  3. Thromboembolism Following Shoulder Arthroscopy

    PubMed Central

    Schick, Cameron W.; Westermann, Robert W.; Gao, Yubo; Abboud, Joseph A.; Wolf, Brian R.

    2014-01-01

    Background: Thromboembolism following shoulder arthroscopy is considered an uncommon complication, with fewer than 50 cases reported in the literature. Arthroscopy of the shoulder is one of the most commonly performed orthopaedic procedures, with low associated risks. Purpose: To identify potential risk factors for the development of venous thromboembolism (VTE) following shoulder arthroscopy and to determine the overall incidence of this complication. Study Design: Case-control study; Level of evidence, 3. Methods: A retrospective case-control review was performed of patients who developed symptomatic deep venous thrombosis (DVT) or pulmonary embolism (PE) following shoulder arthroscopy. Multiple surgeons from across North America were queried. For every case of DVT or PE identified, 2 control cases of shoulder arthroscopy were analyzed. The incidence of DVT/PE following shoulder arthroscopy was determined. A univariate analysis and a multivariate logistic regression model were conducted to identify any potential risk factors for the development of VTE following shoulder arthroscopy. Results: A total of 17 surgeons participated in this study and had performed a total of 15,033 cases of shoulder arthroscopy from September 2002 through August 2011. Eleven of the 17 participating surgeons had had a patient with a VTE complication during this time frame. The incidence of VTE in the 15,033 cases was 0.15%; 22 patients of the 15,033 patients had a DVT (n = 15) and/or PE (n = 8). Forty-four control cases were also analyzed. Univariate and multivariate analyses were performed. No significant risk factors were identified other than patient positioning. All cases and controls were positioned in the beach-chair position for surgery. Conclusion: The results of this study show that although rare, VTE occurs following shoulder arthroscopy at a rate of 0.15%. The variables analyzed in the cases of VTE compared with the control cases did not show any significant risk factors. All

  4. Expeditionary Operations Require Joint Force Capabilities in the Future Operating Environment

    DTIC Science & Technology

    2013-03-01

    point for civilian and military expeditions. Chapter Two looks at the existing joint expeditionary architecture to provide the foundation for what the...Jun., 1989): pp. 893-894, http://www.jstor.org/stable/1873989. Moskos, Charles C., John Allen Williams,and David R.Segal, eds. "The Postmodern

  5. Optimizing Multi-Ship, Multi-Mission Operational Planning for the Joint Force Maritime Component Commander

    DTIC Science & Technology

    2009-03-01

    joint, combined, or interagency objectives (FFC, 2007). Zvijac (2008) points out that planning, information, and relationships are critical at the... Zvijac , D. J. (2008). Characteristics of the MHQ/MOC concept. Center for Naval Analysis, CRM D0018329.A4/1Rev. Available from http://www.cna.org/about

  6. Bilateral shoulder septic arthritis in a fit and well 47-year-old man.

    PubMed

    Hotonu, Sesi Ayodele; Khan, Shoaib; Jeavons, Richard

    2015-11-20

    Bilateral septic arthritis of the shoulder is uncommon in the immunocompetent patient with no previous risk factors for joint infection, and is thus easily missed. Septic arthritis is associated with significant rates of morbidity and mortality. Early diagnosis and management is the key to a favourable outcome; septic arthritis should be considered as a differential diagnosis in the unwell patient presenting with shoulder pain and reduced range of joint movement. We present a case of a 47-year-old previously fit and well man with bilateral shoulder septic arthritis. We will also review the current literature on management and long-term outcomes of patients with septic arthritis of the glenohumeral joint.

  7. Reverse total shoulder arthroplasty: research models

    PubMed Central

    PETRILLO, STEFANO; LONGO, UMILE GIUSEPPE; GULOTTA, LAWRENCE V.; BERTON, ALESSANDRA; KONTAXIS, ANDREAS; WRIGHT, TIMOTHY; DENARO, VINCENZO

    2016-01-01

    Purpose the past decade has seen a considerable increase in the use of research models to study reverse total shoulder arthroplasty (RTSA). Nevertheless, none of these models has been shown to completely reflect real in vivo conditions. Methods we performed a systematic review of the literature matching the following key words: “reverse total shoulder arthroplasty” or “reverse total shoulder replacement” or “reverse total shoulder prosthesis” and “research models” or “biomechanical models” or “physical simulators” or “virtual simulators”. The following databases were screened: Medline, Google Scholar, EMBASE, CINAHIL and Ovid. We identified and included all articles reporting research models of any kind, such as physical or virtual simulators, in which RTSA and the glenohumeral joint were reproduced. Results computer models and cadaveric models are the most commonly used, and they were shown to be reliable in simulating in vivo conditions. Bone substitute models have been used in a few studies. Mechanical testing machines provided useful information on stability factors in RTSA. Conclusion because of the limitations of each individual model, additional research is required to develop a research model of RTSA that may reduce the limitations of those presently available, and increase the reproducibility of this technique in the clinical setting. PMID:28217660

  8. Testing thread compounds for rotary-shouldered connections

    SciTech Connect

    Bailey, E.I. ); Smith, J.E. )

    1993-09-01

    Trouble-free rotary-shouldered-connection performance depends on proper joint makeup. Joints must be tight enough to prevent shoulder separation under bending and tensile loads but not so tight that their tensile capacity decreases or the pin or box is damaged. The preload in a connection from tightening depends on the makeup torque and frictional properties of the thread compound. In 1957, Farr developed and published a simplified torque formula to calculate makeup torque: T[sub mu] = ([sigma]A/12)[(p/2[pi])+(r[sub t]K[sub f]/cos [Theta])+r[sub s]K[sub f

  9. Implantable sensor technology: measuring bone and joint biomechanics of daily life in vivo

    PubMed Central

    2013-01-01

    Stresses and strains are major factors influencing growth, remodeling and repair of musculoskeletal tissues. Therefore, knowledge of forces and deformation within bones and joints is critical to gain insight into the complex behavior of these tissues during development, aging, and response to injury and disease. Sensors have been used in vivo to measure strains in bone, intraarticular cartilage contact pressures, and forces in the spine, shoulder, hip, and knee. Implantable sensors have a high impact on several clinical applications, including fracture fixation, spine fixation, and joint arthroplasty. This review summarizes the developments in strain-measurement-based implantable sensor technology for musculoskeletal research. PMID:23369655

  10. Reverse shoulder arthroplasty.

    PubMed

    Smithers, Christopher J; Young, Allan A; Walch, Gilles

    2011-12-01

    The reverse shoulder arthroplasty emerged as a potential solution for those patients who could not be managed effectively with a conventional total shoulder arthroplasty. Grammont revolutionized the design by medializing and distalizing the center of rotation and utilizing a large convex glenoid surface and concave humeral component with a neck-shaft angle of 155°. This design has been highly successful in cuff deficient shoulders, and indications continue to broaden. Many mid-term studies have improved upon the early encouraging results. Long-term studies are starting to emerge, demonstrating good survivorship, but progressive functional and radiographic deterioration continue to be concerning. Careful patient selection and attention to appropriate technique are required to reduce the current high rate of complications. New prosthesis designs are continuing to develop to address some of these limitations.

  11. Shoulder impingement syndrome in relation to shoulder intensive work

    PubMed Central

    Frost, P.; Andersen, J. H.

    1999-01-01

    OBJECTIVES: To analyse the risk of shoulder impingement syndrome relative to shoulder intensive work. METHODS: A cross sectional study of a historical cohort of 1591 workers employed between 1986 and 1993 at a slaughterhouse or a chemical factory. Workers not doing tasks in slaughtering or meat processing constituted the reference group. Intensity of shoulder work in meat processing tasks was assessed by video based observations. Information on shoulder disorders was collected by questionnaire and by physical examinations. Impingement syndrome was diagnosed when shoulder symptoms had been present for at least 3 months during the past year and there were signs of subacromial impingement in the corresponding shoulder at physical examination. Shoulder function was assessed at the same occasion with the Constant scoring technique. Prevalence of shoulder impingement syndrome was analysed according to job title and cumulative exposure. RESULTS: Prevalence ratio for shoulder impingement syndrome was 5.27 (95% confidence interval (95% CI), 2.09 to 12.26) among currently working and 7.90 (95% CI, 2.94 to 21.18) among former slaughterhouse workers. Transformed model based prevalence ratios according to years in slaughterhouse work showed an overall association between cumulative exposure and risk for shoulder impingement syndrome. CONCLUSIONS: This study supports the hypothesis that shoulder intensive work is a risk factor for impingement syndrome of the shoulder. Despite the historical cohort design healthy worker selection may have influenced the exposure- response relation found.   PMID:10472322

  12. Miniopen coracohumeral ligament release and manipulation for idiopathic frozen shoulder.

    PubMed

    Eid, Abdelsalam

    2012-07-01

    In the management of idiopathic frozen shoulder, manipulation under anaesthesia is known to have serious potential complications including fractures and intra-articular injuries. Arthroscopy is a safer treatment modality but requires special instruments, experience, and involves added cost. The aim of this work was to study the use of miniopen Coracohumeral ligament release and manipulation of the shoulder as a safe and simple method of treating idiopathic frozen shoulder that could be performed as a quick procedure under short duration anaesthesia obtaining a significant improvement of shoulder function while avoiding complications that are feared to occur with the use of manipulation under anaesthesia. Miniopen Coracohumeral ligament release is performed through a 3-cm incision. The Coracohumeral ligament is divided, and then the shoulder is manipulated without undue force. A case series including fifteen patients (19 shoulders) with idiopathic frozen shoulder operated by this technique is described. Miniopen Coracohumeral ligament release and manipulation is a quick procedure that may be performed under short duration anaesthesia obtaining a significant improvement of shoulder function meanwhile avoiding complications that are feared to occur with the use of manipulation under anaesthesia.

  13. Efficacy of a trunk orthosis with joints providing resistive force on low back load during level walking in elderly persons

    PubMed Central

    Katsuhira, Junji; Matsudaira, Ko; Oka, Hiroyuki; Iijima, Shinno; Ito, Akihiro; Yasui, Tadashi; Yozu, Arito

    2016-01-01

    Purpose The effects of lumbosacral and spinal orthoses on low back pain and gait are not exactly clear. We previously developed a trunk orthosis with joints providing resistive force on low back load to decrease such load, and confirmed its positive effects during level walking in healthy young adults. Therefore, we aimed to determine the efficacy of this trunk orthosis during level walking in healthy elderly subjects. Methods Fifteen community-dwelling elderly subjects performed level walking at a self-selected speed without an orthosis, with our orthosis, and with a lumbosacral orthosis. Kinematic and kinetic data were recorded using a three-dimensional motion analysis system, and erector spinae activity was recorded by electromyography. Results When comparing the three conditions, our orthosis showed the following effects: it decreased the peak extension moment, increased the peak flexion moment, decreased the lateral bending angle, increased the peak thoracic extension angle, and had significantly lower erector spinae activity and significantly larger peak pelvic forward tilt angles. Conclusion Our orthosis with joints providing resistive force decreased low back load and modified trunk and pelvis alignments during level walking in healthy elderly people. PMID:27877028

  14. Robotics in shoulder rehabilitation

    PubMed Central

    Sicuri, Chiara; Porcellini, Giuseppe; Merolla, Giovanni

    2014-01-01

    Summary In the last few decades, several researches have been conducted in the field of robotic rehabilitation to meet the intensive, repetitive and task-oriented training, with the goal to recover the motor function. Up to now, robotic rehabilitation studies of the upper extremity have generally focused on stroke survivors leaving less explored the field of orthopaedic shoulder rehabilitation. In this review we analyse the present status of robotic technologies, in order to understand which are the current indications and which may be the future perspective for their application in both neurological and orthopaedic shoulder rehabilitation. PMID:25332937

  15. Using your shoulder after surgery

    MedlinePlus

    ... medlineplus.gov/ency/patientinstructions/000175.htm Using your shoulder after surgery To use the sharing features on ... please enable JavaScript. You had surgery on your shoulder to repair a muscle, tendon, or cartilage tear. ...

  16. Blue Moon Rising? Air Force Institutional Challenges to Producing Senior Joint Leaders

    DTIC Science & Technology

    2010-05-20

    in Iraq, Kurdistan , Somalia, Afghanistan, Sudan, and Kosovo during the 1990s, Belote asserts, “common sense argues that when airpower is central to...science) is central to the concept and execution of command and control (C2): The art of commanding Air Force forces lies in the ability to...commander’s ability to understand and visualize the situation ( art ) forms the foundation for describing and directing actions (science) to achieve

  17. Experimental Validation of a Tibiofemoral Model for Analyzing Joint Force Distribution

    PubMed Central

    Miller, Emily J.; Riemer, Rose F.; Haut Donahue, Tammy L.; Kaufman, Kenton R.

    2009-01-01

    A computational model of the tibiofemoral joint utilizing the discrete element analysis method has been developed and validated with human cadaveric knees. The computational method can predict load distributions to within a Root Mean Square Error (RMSE) of 3.6%. The model incorporates subject-specific joint geometry and the health of the subjects’ articular cartilage to determine the cartilage stiffness. It also includes the collateral and cruciate ligaments and utilizes stiffness values derived from literature for these elements. Comparisons of the total load, peak load, and peak load location for axial, varus, and valgus loading conditions confirmed that there was less than 4% RMSE between the analytical and experimental results. The model presented in this paper can generate results with minimal computational time and it can be used as a non-invasive method for characterizing and monitoring subject-specific knee loading patterns. PMID:19389677

  18. Cyber Power for the Joint Force Commander: An Operational Design Framework

    DTIC Science & Technology

    2014-03-26

    William A. Owens, Kenneth W. Dam, and Herbert S. Lin, eds, Technology, Policy, Law, and Ethics Regarding U.S. Acquisition and Use of Cyberattack...and computer systems used in carrying out a mission.” 27 George J. Franz III, "Effective Synchronization and Integration of Effects Through...2007. Franz, George J. "Effective Synchronization and Integration of Effects Through Cyberspace for the Joint Warfighter." U.S. Cyber Command

  19. A Question of Balance: Metrics or Art for Joint Force Decision-Making?

    DTIC Science & Technology

    2008-04-23

    1 William J. Hartig, “Problem Solving and the Military Professional,” Joint Military Operations...The chapter identifies the contribution of William Lind and other civilian reformers that were integral to a professional debate over Army doctrine... William S. Murray, “A Will to Measure - Measures of Effectiveness in Military Decision-making,” Parameters (Autumn 2001), 1. http://www.carlisle.army.mil

  20. Strategic Planning to Conduct Joint Force Network Operations: A Content Analysis of NETOPS Organizations Strategic Plans

    DTIC Science & Technology

    2007-03-01

    information dominance , Joint Network Operations (NETOPS) organizations need to be strategically aligned. As result, to enhance the capabilities-based effects of NETOPS and reduce our NETOP infrastructures susceptibility to compromise. Once the key organizations were identified, their strategic plans were analyzed using a structured content analysis framework. The results illustrated that the strategic plans were aligned with the community of interests tasking to conduct NETOPS. Further research is required into the strategic alignment beyond the strategic

  1. Focus on China. Joint Force Quarterly, Issue 47, 4th Quarter 2007

    DTIC Science & Technology

    2007-01-01

    appointing an “Africa czar” with the responsibility and authority to integrate and coordinate U.S. initiatives and policies. Coupled with the apparently...defensive actions. The emphasis on offensive operations, air strikes, and strategic mobility ( coupled with the PLA-wide empha- sis on joint operations...development. Thus, it may face a limited backlash in the coming years about its foreign investment practices. Recent anti-China riots at a copper mine in

  2. Unintended Consequences of the Goldwater-Nichols Act (Joint Force Quarterly, Spring 1998)

    DTIC Science & Technology

    1998-01-01

    challenge for commanders since the Peloponnesian War. It is also irrelevant to the issue of military decision - making at the seat of government. Joint...the decisions the govern- ment makes , not only in military policy and war but in foreign, defense, economic, and social pol- icy (for much military...sional military] men and women . . . to be set aside for the decisions of the civilians whose decisions have not been wrapped in war[?] We lost in

  3. Effect of reverse shoulder design philosophy on muscle moment arms.

    PubMed

    Hamilton, Matthew A; Diep, Phong; Roche, Chris; Flurin, Pierre Henri; Wright, Thomas W; Zuckerman, Joseph D; Routman, Howard

    2015-04-01

    This study analyzes the muscle moment arms of three different reverse shoulder design philosophies using a previously published method. Digital bone models of the shoulder were imported into a 3D modeling software and markers placed for the origin and insertion of relevant muscles. The anatomic model was used as a baseline for moment arm calculations. Subsequently, three different reverse shoulder designs were virtually implanted and moment arms were analyzed in abduction and external rotation. The results indicate that the lateral offset between the joint center and the axis of the humerus specific to one reverse shoulder design increased the external rotation moment arms of the posterior deltoid relative to the other reverse shoulder designs. The other muscles analyzed demonstrated differences in the moment arms, but none of the differences reached statistical significance. This study demonstrated how the combination of variables making up different reverse shoulder designs can affect the moment arms of the muscles in different and statistically significant ways. The role of humeral offset in reverse shoulder design has not been previously reported and could have an impact on external rotation and stability achieved post-operatively.

  4. Platelet-Rich Plasma for Frozen Shoulder: A Case Report

    PubMed Central

    Aslani, Hamidreza; Nourbakhsh, Seyed Taghi; Zafarani, Zohreh; Ahmadi-Bani, Monireh; Ananloo, Mohammad Ebrahim Shahsavand; Beigy, Maani; Salehi, Shahin

    2016-01-01

    Frozen shoulder is a glenohumeral joint disorder that movement because of adhesion and the existence of fibrosis in the shoulder capsule. Platelet-rich plasma can produce collagen and growth factors, which increases stem cells and consequently enhances the healing. To date, there is no evidence regarding the effectiveness of platelet-rich plasma in frozen shoulder. A 45-year-old man with shoulder adhesive capsulitis volunteered for this treatment. He underwent two consecutive platelet-rich plasma injections at the seventh and eighth month after initiation of symptoms. We measured pain, function, ROM by the visual analogue scale (VAS), scores from the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and goniometer; respectively. After first injection, the patient reported 60% improvement regarding diurnal shoulder pain, and no night pain. Also, two-fold improvement for ROM and more than 70% improvement for function were reported. This study suggests the use of platelet-rich plasma in frozen shoulder to be tested in randomized trials. PMID:26894228

  5. Pathologic dislocation of the shoulder secondary to septic arthritis: a case report

    PubMed Central

    2009-01-01

    Septic arthritis of the shoulder is uncommon in adults, and complete dislocation of the glenohumeral joint following septic arthritis is extremely rare. We report a case of pathologic shoulder dislocation secondary to septic arthritis in an intravenous drug abuser. PMID:20062648

  6. Analysis of joint force and torque for the human and non-human ape foot during bipedal walking with implications for the evolution of the foot

    PubMed Central

    Wang, Weijie; Abboud, Rami J; Günther, Michael M; Crompton, Robin H

    2014-01-01

    The feet of apes have a different morphology from those of humans. Until now, it has merely been assumed that the morphology seen in humans must be adaptive for habitual bipedal walking, as the habitual use of bipedal walking is generally regarded as one of the most clear-cut differences between humans and apes. This study asks simply whether human skeletal proportions do actually enhance foot performance during human-like bipedalism, by examining the influence of foot proportions on force, torque and work in the foot joints during simulated bipedal walking. Skeletons of the common chimpanzee, orangutan, gorilla and human were represented by multi-rigid-body models, where the components of the foot make external contact via finite element surfaces. The models were driven by identical joint motion functions collected from experiments on human walking. Simulated contact forces between the ground and the foot were found to be reasonably comparable with measurements made during human walking using pressure- and force-platforms. Joint force, torque and work in the foot were then predicted. Within the limitations of our model, the results show that during simulated human-like bipedal walking, (1) the human and non-human ape (NHA) feet carry similar joint forces, although the distributions of the forces differ; (2) the NHA foot incurs larger joint torques than does the human foot, although the human foot has higher values in the first tarso-metatarsal and metatarso-phalangeal joints, whereas the NHA foot incurs higher values in the lateral digits; and (3) total work in the metatarso-phalangeal joints is lower in the human foot than in the NHA foot. The results indicate that human foot proportions are indeed well suited to performance in normal human walking. PMID:24925580

  7. Estimation of Human Arm Joints Using Two Wireless Sensors in Robotic Rehabilitation Tasks.

    PubMed

    Bertomeu-Motos, Arturo; Lledó, Luis D; Díez, Jorge A; Catalan, Jose M; Ezquerro, Santiago; Badesa, Francisco J; Garcia-Aracil, Nicolas

    2015-12-04

    This paper presents a novel kinematic reconstruction of the human arm chain with five degrees of freedom and the estimation of the shoulder location during rehabilitation therapy assisted by end-effector robotic devices. This algorithm is based on the pseudoinverse of the Jacobian through the acceleration of the upper arm, measured using an accelerometer, and the orientation of the shoulder, estimated with a magnetic angular rate and gravity (MARG) device. The results show a high accuracy in terms of arm joints and shoulder movement with respect to the real arm measured through an optoelectronic system. Furthermore, the range of motion (ROM) of 50 healthy subjects is studied from two different trials, one trying to avoid shoulder movements and the second one forcing them. Moreover, the shoulder movement in the second trial is also estimated accurately. Besides the fact that the posture of the patient can be corrected during the exercise, the therapist could use the presented algorithm as an objective assessment tool. In conclusion, the joints' estimation enables a better adjustment of the therapy, taking into account the needs of the patient, and consequently, the arm motion improves faster.

  8. The painful shoulder.

    PubMed

    Flicker, P L

    1980-06-01

    Acute peritendinitis calcarea, adhesive capsulitis, and anterior acromion impingement syndrome are common problems of the shoulder. Needle and drug therapy are indicated to relieve pain in the treatment of acute cases, with a regular home program of exercise essential for successful results in all cases. Surgery is recommended only if the nonoperative approach is unsuccessful.

  9. Common Shoulder Injuries in American Football Athletes.

    PubMed

    Gibbs, Daniel B; Lynch, T Sean; Nuber, Erika D; Nuber, Gordon W

    2015-01-01

    American football is a collision sport played by athletes at high speeds. Despite the padding and conditioning in these athletes, the shoulder is a vulnerable joint, and injuries to the shoulder girdle are common at all levels of competitive football. Some of the most common injuries in these athletes include anterior and posterior glenohumeral instability, acromioclavicular pathology (including separation, osteolysis, and osteoarthritis), rotator cuff pathology (including contusions, partial thickness, and full thickness tears), and pectoralis major and minor tears. In this article, we will review the epidemiology and clinical and radiographic workup of these injuries. We also will evaluate the effectiveness of surgical and nonsurgical management specifically related to high school, collegiate, and professional football athletes.

  10. The Rotator Interval of the Shoulder

    PubMed Central

    Frank, Rachel M.; Taylor, Dean; Verma, Nikhil N.; Romeo, Anthony A.; Mologne, Timothy S.; Provencher, Matthew T.

    2015-01-01

    Biomechanical studies have shown that repair or plication of rotator interval (RI) ligamentous and capsular structures decreases glenohumeral joint laxity in various directions. Clinical outcomes studies have reported successful outcomes after repair or plication of these structures in patients undergoing shoulder stabilization procedures. Recent studies describing arthroscopic techniques to address these structures have intensified the debate over the potential benefit of these procedures as well as highlighted the differences between open and arthroscopic RI procedures. The purposes of this study were to review the structures of the RI and their contribution to shoulder instability, to discuss the biomechanical and clinical effects of repair or plication of rotator interval structures, and to describe the various surgical techniques used for these procedures and outcomes. PMID:26779554

  11. [Shoulder Surgery in the Elderly Patient].

    PubMed

    Meyer, Dominik C; Wieser, Karl

    2016-01-20

    Elderly patients may be different from the average population in regard to the treatment of shoulder disorders. Challenges are the decreased quality of bone, tendons and cartilage, decreased blood perfusion and a generally aged biology. The advantages however are the often more realistic expectations and more cautious use of the extremity, and the limited life expectancy of prosthetic implants is a less pressing issue. Local pathologies such as in the AC-joint or long head of the biceps may also in the aged patient be treated with infiltration or arthroscopic means. If however large rotator cuff tears and osteoarthritis are present, (reverse) total shoulder implants are the treatment of choice due to the high reliability and uncomplicated rehabilitation.

  12. Conference-EC-US Task Force Joint US-EU Workshop on Metabolomics and Environmental Biotechnology

    SciTech Connect

    PI: Lily Y. Young Co-PI: Gerben J. Zylstra

    2009-06-04

    Since 1990, the EC-US Task Force on Biotechnology Research has been coordinating transatlantic efforts to guide and exploit the ongoing revolution in biotechnology and the life sciences. The Task Force was established in June 1990 by the European Commission and the White House Office of Science and Technology Policy. The Task Force has acted as an effective forum for discussion, coordination, and development of new ideas for the last 18 years. Task Force members are European Commission and US Government science and technology administrators who meet annually to enhance communication across the Atlantic, and to encourage collaborative research. Through sponsoring workshops, and other activities, the Task Force also brings together scientific leaders and early career researchers from both sides of the Atlantic to forecast research challenges and opportunities and to promote better links between researchers. Over the years, by keeping a focus on the future of science, the Task Force has played a key role in establishing a diverse range of emerging scientific fields, including biodiversity research, neuroinformatics, genomics, nanobiotechnology, neonatal immunology, transkingdom molecular biology, biologically-based fuels, and environmental biotechnology. The EC-US Task Force has sponsored a number of Working Groups on topics of mutual transatlantic interest. The idea to create a Working Group on Environmental Biotechnology research was discussed in the Task Force meeting of October 1993. The EC-US Working Group on Environmental Biotechnology set as its mission 'To train the next generation of leaders in environmental biotechnology in the United States and the European Union to work collaboratively across the Atlantic.' Since 1995, the Working Group supported three kinds of activities, all of which focus one early career scientists: (1) Workshops on the use of molecular methods and genomics in environmental biotechnology; (2) Short courses with theoretical, laboratory

  13. Review of Joint Forces Intelligence Command Response to 9/11 Commission

    DTIC Science & Technology

    2008-09-23

    Gary Campbell at (703) 604-8835 (DSN 664-8835). Suggestions for Future Evaluations To suggest ideas for or to request future evaluations of Defense...Inspector General." (U) Questions should be directed to Mr. Gary Campbell at (703) 604 8835 (DSN 664 8835). At management’s request, we will provide...NOFORN I i l I I I I’ r ’ I SECRET/INOFORN SECRETfNOiORH Appended below uro the Joint Fo1·ce Headquarter:~. Homeland St"Curiry Command’s

  14. Distribution of joint local and total size and of extension for avalanches in the Brownian force model

    NASA Astrophysics Data System (ADS)

    Delorme, Mathieu; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-05-01

    The Brownian force model is a mean-field model for local velocities during avalanches in elastic interfaces of internal space dimension d , driven in a random medium. It is exactly solvable via a nonlinear differential equation. We study avalanches following a kick, i.e., a step in the driving force. We first recall the calculation of the distributions of the global size (total swept area) and of the local jump size for an arbitrary kick amplitude. We extend this calculation to the joint density of local and global sizes within a single avalanche in the limit of an infinitesimal kick. When the interface is driven by a single point, we find new exponents τ0=5 /3 and τ =7 /4 , depending on whether the force or the displacement is imposed. We show that the extension of a "single avalanche" along one internal direction (i.e., the total length in d =1 ) is finite, and we calculate its distribution following either a local or a global kick. In all cases, it exhibits a divergence P (ℓ ) ˜ℓ-3 at small ℓ . Most of our results are tested in a numerical simulation in dimension d =1 .

  15. Distribution of joint local and total size and of extension for avalanches in the Brownian force model.

    PubMed

    Delorme, Mathieu; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-05-01

    The Brownian force model is a mean-field model for local velocities during avalanches in elastic interfaces of internal space dimension d, driven in a random medium. It is exactly solvable via a nonlinear differential equation. We study avalanches following a kick, i.e., a step in the driving force. We first recall the calculation of the distributions of the global size (total swept area) and of the local jump size for an arbitrary kick amplitude. We extend this calculation to the joint density of local and global sizes within a single avalanche in the limit of an infinitesimal kick. When the interface is driven by a single point, we find new exponents τ_{0}=5/3 and τ=7/4, depending on whether the force or the displacement is imposed. We show that the extension of a "single avalanche" along one internal direction (i.e., the total length in d=1) is finite, and we calculate its distribution following either a local or a global kick. In all cases, it exhibits a divergence P(ℓ)∼ℓ^{-3} at small ℓ. Most of our results are tested in a numerical simulation in dimension d=1.

  16. A Kinetic Chain Approach for Shoulder Rehabilitation

    PubMed Central

    McMullen, John; Uhl, Timothy L.

    2000-01-01

    Objective: To introduce an approach to shoulder rehabilitation that integrates the kinetic chain throughout the rehabilitation program while providing the theoretical rationale for this program. Background: The focus of a typical rehabilitation program is to identify and treat the involved structures. However, in activities of sport and daily life, the body does not operate in isolated segments but rather works as a dynamic unit. Recently, rehabilitation programs have emphasized closed kinetic chain exercises, core-stabilization exercises, and functional programs. These components are implemented as distinct entities and are used toward the end of the rehabilitation program. Description: Kinetic chain shoulder rehabilitation incorporates the kinetic link biomechanical model and proximal-to-distal motor-activation patterns with proprioceptive neuromuscular facilitation and closed kinetic chain exercise techniques. This approach focuses on movement patterns rather than isolated muscle exercises. Patterns sequentially use the leg, trunk, and scapular musculature to activate weakened shoulder musculature, gain active range of motion, and increase strength. The paradigm of kinetic chain shoulder rehabilitation suggests that functional movement patterns and closed kinetic chain exercises should be incorporated throughout the rehabilitation process. Clinical Advantages: The exercises in this approach are consistent with biomechanical models, apply biomechanical and motor control theory, and work toward sport specificity. The exercises are designed to stimulate weakened tissue by motion and force production in the adjacent kinetic link segments. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8. PMID:16558646

  17. Force.

    ERIC Educational Resources Information Center

    Gamble, Reed

    1989-01-01

    Discusses pupil misconceptions concerning forces. Summarizes some of Assessment of Performance Unit's findings on meaning of (1) force, (2) force and motion in one dimension and two dimensions, and (3) Newton's second law. (YP)

  18. Is there a low-back cost to hip-centric exercise? Quantifying the lumbar spine joint compression and shear forces during movements used to overload the hips.

    PubMed

    Frost, David M; Beach, Tyson; Fenwick, Chad; Callaghan, Jack; McGill, Stuart

    2012-05-01

    The aim of this study was to quantify joint compression and shear forces at L4/L5 during exercises used to overload the hips. Nine men performed 36 "walking" trials using two modalities: (1) sled towing and (2) exercise bands placed around the ankles. Participants completed forward, backward, and lateral trials with bent and straight legs at three separate loads. Surface electromyography (EMG) was recorded bilaterally from eight torso and thigh sites, upper body and lumbar spine motion were quantified, and hand forces were measured. An EMG-driven musculoskeletal model was used to estimate the muscular contribution to joint compression and shear. Peak reaction, muscle and joint compression and shear forces, and peak gluteus medius and maximus activity were calculated. Significant differences were noted in each dependent measure; however, they were dependent on direction of travel, leg position, and load. The highest joint compression and shear forces for the sled and band conditions were 4378 N and 626 N, and 3306 N and 713 N, respectively. In general, increasing the band tension had little effect on all dependent measures, although a load-response was found during the sled conditions. Before using any exercise to improve hip function, the potential benefits should be weighed against "costs" to neighbouring joints.

  19. Effect of hammer mass on upper extremity joint moments.

    PubMed

    Balendra, Nilanthy; Langenderfer, Joseph E

    2017-04-01

    This study used an OpenSim inverse-dynamics musculoskeletal model scaled to subject-specific anthropometrics to calculate three-dimensional intersegmental moments at the shoulder, elbow and wrist while 10 subjects used 1 and 2 lb hammers to drive nails. Motion data were collected via an optoelectronic system and the interaction of the hammer with nails was recorded with a force plate. The larger hammer caused substantial increases (50-150%) in moments, although increases differed by joint, anatomical component, and significance of the effect. Moment increases were greater in cocking and strike/follow-through phases as opposed to swinging and may indicate greater potential for injury. Compared to shoulder, absolute increases in peak moments were smaller for elbow and wrist, but there was a trend toward larger relative increases for distal joints. Shoulder rotation, elbow varus-valgus and pronation-supination, and wrist radial-ulnar deviation and rotation demonstrated large relative moment increases. Trial and phase durations were greater for the larger hammer. Changes in moments and timing indicate greater loads on musculoskeletal tissues for an extended period with the larger hammer. Additionally, greater variability in timing with the larger hammer, particularly for cocking phase, suggests differences in control of the motion. Increased relative moments for distal joints may be particularly important for understanding disorders of the elbow and wrist associated with hammer use.

  20. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    SciTech Connect

    Shur, V. Ya. Zelenovskiy, P. S.

    2014-08-14

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  1. Impact of the Joint Task Force on Undergraduate Physics Programs for Innovation and Entrepreneurship Education in Physics

    NASA Astrophysics Data System (ADS)

    Arion, Douglas

    The Joint Task Force on Undergraduate Physics Programs has worked diligently to develop recommendations for what physics programs could and should be doing to prepare graduates for 21st century careers. While the `traditional' physics curriculum has served for many years, the demands of the new workforce, and the recognition that only a few percent of physics students actually become faculty - the vast majority entering the workforce and applying their skills to a very diverse range of problems, projects, and products - implies that a review of the education undergraduates receives is in order. The outcomes of this study point to the need to provide greater connection between the education process and the actual skills, knowledge, and abilities that the workplace demands. This presentation will summarize these considerations, and show how entrepreneurship and innovation programs and curricula are a particularly effective means of bringing these elements to physics students.

  2. Long-latency reflexes of elbow and shoulder muscles suggest reciprocal excitation of flexors, reciprocal excitation of extensors, and reciprocal inhibition between flexors and extensors.

    PubMed

    Kurtzer, Isaac; Meriggi, Jenna; Parikh, Nidhi; Saad, Kenneth

    2016-04-01

    Postural corrections of the upper limb are required in tasks ranging from handling an umbrella in the changing wind to securing a wriggling baby. One complication in this process is the mechanical interaction between the different segments of the arm where torque applied at one joint induces motion at multiple joints. Previous studies have shown the long-latency reflexes of shoulder muscles (50-100 ms after a limb perturbation) account for these mechanical interactions by integrating information about motion of both the shoulder and elbow. It is less clear whether long-latency reflexes of elbow muscles exhibit a similar capability and what is the relation between the responses of shoulder and elbow muscles. The present study utilized joint-based loads tailored to the subjects' arm dynamics to induce well-controlled displacements of their shoulder and elbow. Our results demonstrate that the long-latency reflexes of shoulder and elbow muscles integrate motion from both joints: the shoulder and elbow flexors respond to extension at both joints, whereas the shoulder and elbow extensors respond to flexion at both joints. This general pattern accounts for the inherent flexion-extension coupling of the two joints arising from the arm's intersegmental dynamics and is consistent with spindle-based reciprocal excitation of shoulder and elbow flexors, reciprocal excitation of shoulder and elbow extensors, and across-joint inhibition between the flexors and extensors.

  3. Teaching Strategy in the 21st Century (Joint Force Quarterly, Issue 52, 1st Quarter 2009)

    DTIC Science & Technology

    2009-01-01

    organizing principle should be regional studies, not military or diplomatic history , not political science, not great power politics, and most certainly not...military history scholars without forcing the two disciplines to integrate their research, results, or teaching. This approach is nicely suited for...mitigating risks where possible , and connecting political purpose with means within the boundaries set by policy. Strategy is the common process

  4. Can the Army Provide Bulk Petroleum Support to Joint Force 2020?

    DTIC Science & Technology

    2013-03-01

    distribution system (the IPDS is a portable, tactical pipeline with its own pumps and bags). This lack of capability in the Active force limits the...previously planned and supervised construction of IPDS no longer exists. That task now resides with the Sustainment Brigade and CSSB, who are given no...skilled engineer support and petroleum headquarters oversight of IPDS construction.33 To address these gaps in Army petroleum operations, CASCOM

  5. Maritime-Based UAVs: A Key to Success for the Joint Force Commander

    DTIC Science & Technology

    2015-05-18

    Navy. 14. ABSTRACT Historically, drones have been used extensively to support a plethora of U.S. military operations from land-based locations; the...Vehicle v Abstract Historically, drones have been used extensively to support a plethora of U.S. military operations...Storm commanders soon realized that the “utility of drones ” would provide a “force multiplier” for future operations.xii TRANSFORMING THE FUTURE

  6. Joint Force Quarterly, Issue 49, 2nd Quarter 2008: Focus on Airpower

    DTIC Science & Technology

    2008-04-01

    equipment, and quality of life they deserve. Taking care of Airmen calls for leadership they can trust with their lives. It also requires a concerted...n Quality of life programs are needed to recruit and retain Reserve Component forces. We must work together to address employer concerns and...Counterinsurgency: Getting Doctrine Right By James S. Corum 98 National Security and Global Climate Change By Sean C. Maybee CORRECTION The JFQ 48 (1st

  7. How Should the Joint Force Handle the Command and Control of Unmanned Aircraft Systems?

    DTIC Science & Technology

    2008-11-18

    sea level (MSL) and high altitude UAVs were those that flew in excess of 18,000 MSL.5 Low altitude 3 John L. Romjue, “The Evolution of the AirLand...include I-Gnat- ER, Hunter, and Hummingbird and are associated with divisions, corps, and Marine Expeditionary Forces. Operational/Theater and... evolution of airpower unfolded in the Middle East, the same 41 Ibid., 81. 42 Ibid., 97. 27 place that Sir Arthur Coningham became so heavily influenced

  8. Joint Warfare of the Armed Forces of the United States. Second Edition.

    DTIC Science & Technology

    2007-11-02

    historians, and practitioners of war, and by carefully keeping those insights up to date. Projection of power is The Armed Forces of the United...operations. This willingness to stand up for includes the willingness to stand up for what we believe is what we believe is right. right even if that...and common defense...." Defense of our nation by carefully keeping those insights up to and its interests defines our reason for date. As we

  9. Combined Joint Task Force-Horn of Africa: Winning the War on Terror with Information Engagement

    DTIC Science & Technology

    2007-06-01

    refugees gained international media attention that the U.S. deployed military forces to alleviate the humanitarian crisis . One of those units was...strategic message because it was too late, in the wrong country and supported the population that had initiated the crisis . This was an example of an...indirect use of diplomatic, economic, information, law enforcement, military, financial, intelligence ( MIDLIFE ), and other instruments of power.” The

  10. Unraveling CORDS: Lessons Learned from a Joint Inter-Agency Task Force (JIATF)

    DTIC Science & Technology

    2009-04-01

    Major- General Sir Charles W. Gwynn (UK) describes three scenarios that require close civil and military operations. Two of those three scenarios...Defense to work together due to the amount of 13 Major General Sir Charles W. Gwynn, Imperial Policing, Global War on Terrorism Occasional Paper 2 (Fort...Infrastructure suffered almost no casualties. The VCI were the political cadre that developed and directed the insurgent force, 205 Moeller , Robert

  11. The Association of Academic Health Sciences Libraries' legislative activities and the Joint Medical Library Association/Association of Academic Health Sciences Libraries Legislative Task Force

    PubMed Central

    Zenan, Joan S.

    2003-01-01

    The Association of Academic Health Sciences Libraries' (AAHSL's) involvement in national legislative activities and other advocacy initiatives has evolved and matured over the last twenty-five years. Some activities conducted by the Medical Library Association's (MLA's) Legislative Committee from 1976 to 1984 are highlighted to show the evolution of MLA's and AAHSL's interests in collaborating on national legislative issues, which resulted in an agreement to form a joint legislative task force. The history, work, challenges, and accomplishments of the Joint MLA/AAHSL Legislative Task Force, formed in 1985, are discussed. PMID:12883581

  12. Force Protection Joint Experiment (FPJE) Battlefield Anti-Intrusion System (BAIS) sensors data analysis and filtering metrics

    NASA Astrophysics Data System (ADS)

    Barngrover, C. M.; Laird, R. T.; Kramer, T. A.; Cruickshanks, J. R.; Cutler, S. H.

    2009-04-01

    The FPJE was an experiment to consider the best way to develop and evaluate a system of systems approach to Force Protection. It was sponsored by Physical Security Equipment Action Group (PSEAG) and Joint Program Manager - Guardian (JPM-G), and was managed by the Product Manager - Force Protection Systems (PM-FPS). The experiment was an effort to utilize existing technical solutions from all branches of the military in order to provide more efficient and effective force protection. The FPJE consisted of four separate Integration Assessments (IA), which were intended as opportunities to assess the status of integration, automation and fusion efforts, and the effectiveness of the current configuration and "system" components. The underlying goal of the FPJE was to increase integration, automation, and fusion of the many different sensors and their data to provide enhanced situational awareness and a common operational picture. One such sensor system is the Battlefield Anti-Intrusion System (BAIS), which is a system of seismic and acoustic unmanned ground sensors. These sensors were originally designed for employment by infantry soldiers at the platoon level to provide early warning of personnel and vehicle intrusion in austere environments. However, when employed around airfields and high traffic areas, the sensitivity of these sensors can cause an excessive number of detections. During the second FPJE-IA all of the BAIS detections and the locations of all Opposing Forces were logged and analyzed to determine the accuracy rate of the sensors. This analysis revealed that with minimal filtering of detections, the number of false positives and false negatives could be reduced substantially to manageable levels while using the sensors within extreme operational acoustic and seismic noise conditions that are beyond the design requirements.

  13. Modulation of the Relationship Between External Knee Adduction Moments and Medial Joint Contact Forces Across Subjects and Activities

    PubMed Central

    Trepczynski, Adam; Kutzner, Ines; Bergmann, Georg; Taylor, William R; Heller, Markus O

    2014-01-01

    Objective The external knee adduction moment (EAM) is often considered a surrogate measure of the distribution of loads across the tibiofemoral joint during walking. This study was undertaken to quantify the relationship between the EAM and directly measured medial tibiofemoral contact forces (Fmed) in a sample of subjects across a spectrum of activities. Methods The EAM for 9 patients who underwent total knee replacement was calculated using inverse dynamics analysis, while telemetric implants provided Fmed for multiple repetitions of 10 activities, including walking, stair negotiation, sit-to-stand activities, and squatting. The effects of the factors “subject” and “activity” on the relationships between Fmed and EAM were quantified using mixed-effects regression analyses in terms of the root mean square error (RMSE) and the slope of the regression. Results Across subjects and activities a good correlation between peak EAM and Fmed values was observed, with an overall R2 value of 0.88. However, the slope of the linear regressions varied between subjects by up to a factor of 2. At peak EAM and Fmed, the RMSE of the regression across all subjects was 35% body weight (%BW), while the maximum error was 127 %BW. Conclusion The relationship between EAM and Fmed is generally good but varies considerably across subjects and activities. These findings emphasize the limitation of relying solely on the EAM to infer medial joint loading when excessive directed cocontraction of muscles exists and call for further investigations into the soft tissue–related mechanisms that modulate the internal forces at the knee. PMID:24470261

  14. Acute calcific periarthritis outside the shoulder: a frequently misdiagnosed condition.

    PubMed Central

    Johnson, G S; Guly, H R

    1994-01-01

    Thirteen patients presented to an accident and emergency (A&E) department with acute calcific periarthritis of joints other than the shoulder. In only three patients was the correct diagnosis made on the initial attendance with inappropriate treatment and delay in recovery as a result. The specific features and guidelines for management of this condition are reviewed. Images Fig. 1 PMID:7804591

  15. Functional anatomy and biomechanics of shoulder stability in the athlete.

    PubMed

    Murray, Iain R; Goudie, Ewan B; Petrigliano, Frank A; Robinson, C Michael

    2013-10-01

    Glenohumeral joint motion results from a complex interplay between static and dynamic stabilizers that require intricate balance and synchronicity. Instability of the shoulder is a commonly encountered problem in active populations, especially young athletes. The underlying pathoanatomy predisposing to further episodes and the needs of individual athletes must be considered in determining the most appropriate treatment.

  16. Consistent accuracy in whole-body joint kinetics during gait using wearable inertial motion sensors and in-shoe pressure sensors.

    PubMed

    Khurelbaatar, Tsolmonbaatar; Kim, Kyungsoo; Lee, SuKyoung; Kim, Yoon Hyuk

    2015-06-01

    To analyze human motion such as daily activities or sports outside of the laboratory, wearable motion analysis systems have been recently developed. In this study, the joint forces and moments in whole-body joints during gait were evaluated using a wearable motion analysis system consisting of an inertial motion measurement system and an in-shoe pressure sensor system. The magnitudes of the joint forces and the moments in nine joints (cervical, thoracic, lumbar, right shoulder, right elbow, right wrist, right hip, right knee, and right ankle) during gait were calculated using the wearable system and the conventional system, respectively, based on a standard inverse dynamics analysis. The averaged magnitudes of the joint forces and moments of five subjects were compared between the wearable and conventional systems in terms of the Pearson's correlation coefficient and the normalized root mean squared error to the maximum value from the conventional system. The results indicated that both the joint forces and joint moments in human whole body joints using wearable inertial motion sensors and in-shoe pressure sensors were feasible for normal motions with a low speed such as walking, although the lower extremity joints showed the strongest correlation and overall the joint moments were associated with relatively smaller correlation coefficients and larger normalized root mean squared errors in comparison with the joint forces. The portability and mobility of this wearable system can provide wide applicability in both clinical and sports motion analyses.

  17. Muscle Activation and Estimated Relative Joint Force During Running with Weight Support on a Lower-Body Positive-Pressure Treadmill.

    PubMed

    Jensen, Bente R; Hovgaard-Hansen, Line; Cappelen, Katrine L

    2016-08-01

    Running on a lower-body positive-pressure (LBPP) treadmill allows effects of weight support on leg muscle activation to be assessed systematically, and has the potential to facilitate rehabilitation and prevent overloading. The aim was to study the effect of running with weight support on leg muscle activation and to estimate relative knee and ankle joint forces. Runners performed 6-min running sessions at 2.22 m/s and 3.33 m/s, at 100%, 80%, 60%, 40%, and 20% body weight (BW). Surface electromyography, ground reaction force, and running characteristics were measured. Relative knee and ankle joint forces were estimated. Leg muscles responded differently to unweighting during running, reflecting different relative contribution to propulsion and antigravity forces. At 20% BW, knee extensor EMGpeak decreased to 22% at 2.22 m/s and 28% at 3.33 m/s of 100% BW values. Plantar flexors decreased to 52% and 58% at 20% BW, while activity of biceps femoris muscle remained unchanged. Unweighting with LBPP reduced estimated joint force significantly although less than proportional to the degree of weight support (ankle). It was concluded that leg muscle activation adapted to the new biomechanical environment, and the effect of unweighting on estimated knee force was more pronounced than on ankle force.

  18. Glenohumeral Joint Kinematics following Clavicular Fracture and Repairs

    PubMed Central

    Walley, Kempland C.; Harlow, Ethan R.; Haghpanah, Babak; Vaziri, Ashkan; Ramappa, Arun J.; DeAngelis, Joseph P.

    2017-01-01

    Background The purpose of this biomechanical study was to determine the effect of shortened clavicle malunion on the center of rotation of the glenohumeral (GH) joint, and the capacity of repair to restore baseline kinematics. Methods Six shoulders underwent automated abduction (ABD) and abbreviated throwing motion (ATM) using a 7-DoF automated upper extremity testing system in combination with an infrared motion capture system to measure the center of rotation of the GH joint. ATM was defined as pure lateral abduction and late cocking phase to the end of acceleration. Torsos with intact clavicle underwent testing to establish baseline kinematics. Then, the clavicles were subjected to midshaft fracture followed by kinematics testing. The fractured clavicles underwent repairs first by clavicle length restoration with plate fixation, and then by wiring of fragments with a 2-cm overlap to simulate shortened malunion. Kinematic testing was conducted after each repair technique. Center of rotation of the GH joint was plotted across all axes to outline 3D motion trajectory and area under the curve. Results Throughout ABD, malunion resulted in increased posterior and superior translation compared to baseline. Plate fixation restored posterior and superior translations at lower abduction angles but resulted in excess anterior and inferior translation at overhead angles. Throughout ATM, all conditions were significantly anterior and superior to baseline. Translation with malunion was situated anterior to the fractured and ORIF conditions at lower angles of external rotation. Plate fixation did not restore baseline anteroposterior or superoinferior translation at any angle measured. Conclusions This study illustrates the complex interplay of the clavicle and the GH joint. While abnormal clavicle alignment alters shoulder motion, restoration of clavicle length does not necessarily restore GH kinematics to baseline. Rehabilitation of the injured shoulder must address the

  19. Bilateral posterior shoulder dislocation after electrical shock: A case report

    PubMed Central

    Ketenci, Ismail Emre; Duymus, Tahir Mutlu; Ulusoy, Ayhan; Yanik, Hakan Serhat; Mutlu, Serhat; Durakbasa, Mehmet Oguz

    2015-01-01

    Introduction Posterior dislocation of the shoulder is a rare and commonly missed injury. Unilateral dislocations occur mostly due to trauma. Bilateral posterior shoulder dislocations are even more rare and result mainly from epileptic seizures. Electrical injury is a rare cause of posterior shoulder dislocation. Injury mechanism in electrical injury is similar to epileptic seizures, where the shoulder is forced to internal rotation, flexion and adduction. Presentation of case This report presents a case of bilateral posterior shoulder dislocation after electrical shock. We were able to find a few individual case reports describing this condition. The case was acute and humeral head impression defects were minor. Our treatment in this case consisted of closed reduction under general anesthesia and applying of orthoses which kept the shoulders in abduction and external rotation. A rehabilitation program was begun after 3 weeks of immobilization. After 6 months of injury the patient has returned to work. 20 months postoperatively, at final follow-up, he was painless and capable of performing all of his daily activities. Discussion The amount of bilateral shoulder dislocations after electrical injury is not reported but is known to be very rare. The aim of this case presentation is to report an example for this rare entity, highlight the difficulties in diagnosis and review the treatment options. Conclusion Physical examination and radiographic evaluation are important for quick and accurate diagnosis. PMID:26904192

  20. Shoulder Arthroplasty, from Indications to Complications: What the Radiologist Needs to Know.

    PubMed

    Lin, Dana J; Wong, Tony T; Kazam, Jonathan K

    2016-01-01

    The replaced shoulder is increasingly encountered by the radiologist, both on a dedicated and incidental basis, in this era of the growing population of aging patients wishing to preserve their mobility and function. Knowledge of the normal biomechanics of the glenohumeral joint-particularly the function of the rotator cuff and the unique relationship of the humeral head to the glenoid-is essential for understanding the need for shoulder replacement and its subsequent complications, because the intent of shoulder arthroplasty is to approximate the normal joint as closely as possible. The most common indications for shoulder arthroplasty are osteoarthritis, inflammatory arthritis, proximal humerus fractures, irreparable rotator cuff tears, rotator cuff arthropathy, and avascular necrosis of the humeral head. Knowledge of the key imaging features of these indications helps facilitate a correlative understanding between the initial diagnosis and the choice of which type of arthroplasty is used-total shoulder arthroplasty, reverse total shoulder arthroplasty, or partial joint replacement (humeral head resurfacing arthroplasty or hemiarthroplasty). The preoperative requirements and usual postoperative appearance of each arthroplasty type are summarized, as well as the complications of shoulder arthroplasty, including those unique to or closely associated with each type of arthroplasty and those that can be encountered with any type of shoulder arthroplasty.