Finger muscle attachments for an OpenSim upper-extremity model.

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements

Metastasierungsverhalten und Prognose von verrukösen Karzinomen -Literaturübersicht und retrospektive Studie-

Die Arbeit umfaßt erstens einen Literaturüberblick über die charakteristischen Merkmale und Besonderheiten des verrukösen Karzinoms (VK) und die Prognose bei unterschiedlichen therapeutischen Herangehensweisen. Von besonderem Interesse ist die LK-Metastasierung von VK. In der Literaturauswertung konnten dabei 18 Fälle ermittelt werden; dabei waren nur in einem Fall Fernmetastasen vorhanden. Die Prognose von VK ist gut bei einer adäquaten chirurgischen Therapie; die Mitbehandlung des Lymphabstromgebietes sollte nicht routinemäßig erfolgen. Zweiter Schwerpunkt der Arbeit ist eine Auswertung des Patientengutes der Klinik und Poliklinik für Mund-, Kiefer- und Gesichtschirurgie der Charité (24 Patienten) und der Hals-Nasen-Ohrenklinik der Charité (13 Patienten) unter der besonderen Fragestellung des Metastasierungsverhaltens und der Prognose von VK. In 2 Fällen wurden LK-Metastasen eines VK festgestellt. In keinem Fall ist das VK als Todesursache eines Patienten bekannt. Bei 8 Patienten traten Rezidive auf. Es wurde festgestellt, daß größere Tumoren schneller und häufiger rezidivieren. Bei der Hälfte der Patienten trat das Rezidiv 4 bis 9 Monate post operationem auf. Die Früherkennung von VK ist wichtig, denn die Prognose ist umso besser, je kleiner der Tumor ist.The paper comprises first an assessment of literature about the characteristics, and the particularities of verrucous carcinoma (VC), and prognosis dependent on the different therapies. Of particular interest is the lymph node metastatic invasion of VC. The assessment of literature showed in 18 cases lymph node metastases; one VC of these had distant metastases. The prognosis of VC is excellent with adequate surgical therapy. Lymph node treatment should not be routine. Second point of the paper is the assessment of data of 24 patients with VC of the Clinic for Oral and Maxillo-Facial surgery of the Charité and 13 patients with VC of the Clinic for Otorhinolaryngology of the Charité with special attention on metastatic invasion and prognosis of VC. Two patients had lymph node metastases caused by a VC. In no case VC is known as cause of death. Eight patients had relapses. Half of these patients had relapse 4 to 9 monthes post operationem. It was established that larger tumors relapse more often and faster. Early detection of VC is necessary, because the prognosis is the better the smaller the tumor is

Anthropometric index finger dimensions of cadaveric specimens [20] and OpenSim model (mm).

<p>Symbol (±) indicates standard deviation in interspecimen variation. Lengths of the phalanges in OpenSim model are calculated by the distance between the origins of two coordinate systems in three-dimensional (3D) Cartesian space, e.g., the center of rotation at MCP and the center of rotation at PIP. Parentheses (Δ) in OpenSim bony dimensions express difference between model dimension and specimen dimension. Skin surface set is scaled in three-dimensions to preserve measured anatomical proportions [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref036" target="_blank">36</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref039" target="_blank">39</a>]. These skin surface (external dimensions) function as upper boundary constraints during optimization.</p><p>Anthropometric index finger dimensions of cadaveric specimens [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref020" target="_blank">20</a>] and OpenSim model (mm).</p

Middle finger moment arm values (mm).

<p>Left MCP curves, PIP and DIP curves represent flex/extension moment arms as a function of flexion (+)/ extension (-). Right MCP curves represent ab/adduction moment arms as a function of abduction (+)/ adduction (-). Solid curves (with plot markers) represent experimentally derived moment arms from anatomical attachment locations, and dotted curves represent optimally estimated moment arms from data-driven optimizations.</p

Middle finger muscle-tendon locations, expressed in OpenSim frame (mm).

<p>Parentheses () values indicate measured muscle-tendon locations [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref005" target="_blank">5</a>], transformed to OpenSim coordinate. ΔR is the Euclidean distance between OpenSim model and experimentally measured attachment sites [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref005" target="_blank">5</a>].</p><p>Middle finger muscle-tendon locations, expressed in OpenSim frame (mm).</p

Flex/extension moment arms (mm) as a function of flexion (+)/ extension (-) at the PIP and DIP joints of the all fingers.

<p>Symbols are the same as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.g002" target="_blank">Fig 2</a>.</p

Measured and derived flex/extension moment arms (mm) as a function of flexion (+)/ extension (-) at the MCP joint of the index finger.

<p>Dotted moment arm values are derived from experimental muscle attachments [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref005" target="_blank">5</a>], and solid moment arm values are direct measurements (n = 7 specimens with mean and standard deviation (error bar); [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref020" target="_blank">20</a>]). Positive values indicate flexion moment arms, negative values indicate extension moment arms, and 0° is full extension.</p

Ring finger moment arm values (mm).

<p>Left MCP curves, PIP and DIP curves represent flex/extension moment arms as a function of flexion (+)/ extension (-). Right MCP curves represent ab/adduction moment arms as a function of abduction (+)/ adduction (-). Solid curves (with plot markers) represent experimentally derived moment arms from anatomical attachment locations, and dotted curves represent optimally estimated moment arms from data-driven optimizations.</p

Flex/extension moment arms (mm) as a function of flexion (+)/ extension (-) at the MCP joint of the all fingers.

<p>Dotted moment arm values are derived from experimentally measured muscle attachments [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref005" target="_blank">5</a>], and solid moment arm values are direct measurements (n = 7 specimens with mean and standard deviation; [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0121712#pone.0121712.ref020" target="_blank">20</a>]). Positive values indicate flexion moment arms, negative values indicate extension moment arms, and 0° is full extension. Blue, green, red and cyan colors represent index, middle, ring and little finger moment arms, respectively.</p