In Vivo Three-Dimensional Mechanical Actions of Individual Flexor-Pronator Muscles: Role in Elbow Valgus Stability

2008 ◽  
Vol 24 (4) ◽  
pp. 325-332 ◽  
Author(s):  
Jason E. Hsu ◽  
Qiyu Peng ◽  
David A. Schafer ◽  
Jason L. Koh ◽  
Gordon W. Nuber ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Force Sensor ◽  
Muscle Group ◽  
Collateral Ligament ◽  
Flexor Carpi Radialis ◽  
Pronator Teres ◽  
Flexor Carpi Ulnaris

The flexor-pronator mass is thought to be the primary dynamic valgus stabilizer of the elbow and protects the ulnar collateral ligament. However, in vivo multiaxis actions of individual muscles of the flexor-pronator group and their roles in valgus stability have not been investigated quantitatively. This study tested the hypothesis that individual muscles of the flexor-pronator muscle group produce a significant varus moment that provides elbow valgus stability. The flexor carpi ulnaris, flexor carpi radialis, and pronator teres were selectively activated, and the resulting multiaxis moments at the elbow measured at 0°, 30°, 60°, and 90° of elbow flexion using a six-axis force sensor were analyzed for their role in generating varus moment and protecting the ulnar collateral ligament. Considerable off-axis moments were generated by each muscle tested. Through the range of elbow flexion, the varus moment was the major component of the multiaxis action of the flexor carpi ulnaris (p< .001). The flexor carpi radialis and pronator teres had significant actions as elbow flexors and pronators (p≤ .032); these muscles also had a significant varus contribution at 90° elbow flexion (p≤.019). The results suggest that the flexor-pronator muscle group plays an important role in valgus stability of the elbow. In particular, the flexor carpi ulnaris creates a significant varus moment, which is important in unloading and protecting the ulnar collateral ligament. Rehabilitation and strengthening of the flexor-pronator muscle group may help prevent failure of the ulnar collateral ligament and may also help compensate for a medially insufficient elbow.

scholarly journals Changes in Medial Elbow Joint Space When Elbow Valgus Stress Is Applied at Different Limb Positions and Loads In Vivo

2021 ◽  
Vol 9 (11) ◽  
pp. 232596712110459
Author(s):  
Kanta Yoshioka ◽  
Kanta Matsuzawa ◽  
Tomoya Ikuta ◽  
Sae Maruyama ◽  
Mutsuaki Edama
Keyword(s):  
Repeated Measures ◽  
Elbow Joint ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Sports Injury ◽  
Joint Space ◽  
Muscle Contractions ◽  
Collateral Ligament ◽  
Valgus Stress

Background: Ulnar collateral ligament (UCL) injury is a common sports injury among overhead-throwing athletes and causes medial elbow pain and instability. UCL injury is generally diagnosed based on symptoms, physical findings, and image evaluation. To standardize the method for evaluating elbow valgus instability, more information is needed regarding changes in the medial elbow joint space (JS) in healthy elbows. Purpose/Hypothesis: The purpose of this study was to measure the JS during the application of elbow valgus stress at different elbow flexion angles and loads and to clarify the presence of defensive muscle contractions during elbow valgus stress. It was hypothesized that the JS will differ according to different limb positions and loads and that defensive contractions will occur when elbow valgus stress is >90 N. Study Design: Controlled laboratory study. Methods: Elbow joints on the nondominant side were examined in 20 healthy male university students (mean age, 21 ± 0.2 years) at 30°, 60°, and 90° of elbow flexion. To create valgus stress on the elbow, loads of 30, 60, 90, 120, and 150 N were applied with a Telos stress device and with gravity stress on the forearm. The medial JS was measured ultrasonographically during the application of elbow valgus stress. Electrodes were attached to the pronator teres muscle, and defensive muscle contractions were measured using electromyography during the application of elbow valgus stress. Repeated-measures analysis of variance and paired t tests were used to compare the JS at each elbow angle and each valgus stress load, and the Bonferroni method was used as a post hoc test. Results: At 30° of elbow flexion, the JS was significantly higher at 30 N versus 0 N and at 60 N versus 0 or 30 N ( P ≤ .018 for all). At 60° of flexion, the JS was significantly higher at 30 N versus 0 N, at 60 N versus 0 and 30 N, and at 90 N versus 0, 30, and 60 N ( P ≤ .024 for all). At 90° of elbow flexion, the JS was significantly higher at 30 N versus 0 N and at 60 N versus 0 and 30 N ( P ≤ .028 for all). Defensive muscle contraction did not occur at any elbow flexion angles at elbow valgus stress ≤60 N. Conclusion: The lack of muscular contraction at elbow valgus stress ≤60 N may reflect the function of the medial collateral ligament. Clinical Relevance: Elbow valgus stress ≤60 N allows for the evaluation of the joint opening.

Mechanical Evaluation of the Pronator Teres Rerouting Tendon Transfer

2004 ◽  
Vol 29 (3) ◽  
pp. 257-262 ◽  
Author(s):  
H. E. J. VEEGER ◽  
M. KREULEN ◽  
M. J. C. SMEULDERS
Keyword(s):  
Biceps Brachii ◽  
External Rotation ◽  
Three Dimensional ◽  
Muscle Length ◽  
Biomechanical Model ◽  
Elbow Flexion ◽  
Axial Rotation ◽  
Original Position ◽  
Pronator Quadratus ◽  
Pronator Teres

We simulated pronator teres rerouting using a three-dimensional biomechanical model of the arm. Simulations comprised the evaluation of changes in muscle length and the moment arm of pronator teres with changes in forearm axial rotation and elbow flexion. The rerouting of Pronator Teres was simulated by defining a path for it through the interosseous membrane with re-attachment to its original insertion. However the effect of moving the insertion to new positions, 2 cm below and above, the original position was also assessed. The effect on total internal rotation and external rotation capacity was determined by calculating the potential moments for pronator teres, supinator, pronator quadratus, biceps brachii and brachioradialis. Pronator teres was found to be a weak internal rotator in extreme pronation, but a strong internal rotator in neutral rotation and in supination. After rerouting pronator teres was only a strong external rotator in full pronation and not at other forearm positions, where the effect of rerouting was comparable to a release procedure.

Anatomic and Biomechanical Evaluation of Ulnar Tunnel Position in Medial Ulnar Collateral Ligament Reconstruction

2019 ◽  
Vol 47 (14) ◽  
pp. 3491-3497 ◽  
Author(s):  
Pascual H. Dutton ◽  
Michael B. Banffy ◽  
Trevor J. Nelson ◽  
Melodie F. Metzger
Keyword(s):  
Motion Tracking ◽  
Full Range ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Joint Line ◽  
Collateral Ligament ◽  
Proximal Ulna ◽  
Tunnel Position ◽  
Fresh Frozen ◽  
Ulnar Tunnel

Background: Although numerous techniques of reconstruction of the medial ulnar collateral ligament (mUCL) have been described, limited evidence exists on the biomechanical implication of changing the ulnar tunnel position despite the fact that more recent literature has clarified that the ulnar footprint extends more distally than was appreciated in the past. Purpose: To evaluate the size and location of the native ulnar footprint and assess valgus stability of the medial elbow after UCL reconstruction at 3 ulnar tunnel locations. Study Design: Controlled laboratory study. Methods: Eighteen fresh-frozen cadaveric elbows were dissected to expose the mUCL. The anatomic footprint of the ulnar attachment of the mUCL was measured with a digitizing probe. The area of the ulnar footprint and midpoint relative to the joint line were determined. Medial elbow stability was tested with the mUCL in an intact, deficient, and reconstructed state after the docking technique, with ulnar tunnels placed at 5, 10, or 15 mm from the ulnotrochlear joint line. A 3-N·m valgus torque was applied to the elbow, and valgus rotation of the ulna was recorded via motion-tracking cameras as the elbow was cycled through a full range of motion. After kinematic testing, specimens were loaded to failure at 70° of elbow flexion. Results: The mean ± SD length of the mUCL ulnar footprint was 27.4 ± 3.3 mm. The midpoint of the anatomic footprint was located between the 10- and 15-mm tunnels across all specimens at a mean 13.6 mm from the joint line. Sectioning of the mUCL increased elbow valgus rotation throughout all flexion angles and was statistically significant from 30° to 100° of flexion as compared with the intact elbow ( P < .05). mUCL reconstruction at all 3 tunnel locations restored stability to near intact levels with no significant differences among the 3 ulnar tunnel locations at any flexion angle. Conclusion: Positioning the ulnar graft fixation site up to 15 mm from the ulnotrochlear joint line does not significantly increase valgus rotation in the elbow. Clinical Relevance: A more distal ulnar tunnel may be a viable option to accommodate individual variation in morphology of the proximal ulna or in a revision setting.

AN ANATOMICAL STUDY OF THE LIGAMENTS OF THE ULNAR COMPARTMENT OF THE WRIST

Hand Surgery ◽  
2003 ◽  
Vol 08 (02) ◽  
pp. 219-226 ◽  
Author(s):  
Saburo Sasao ◽  
Moroe Beppu ◽  
Hitoshi Kihara ◽  
Kazuaki Hirata ◽  
Masayuki Takagi
Keyword(s):  
Three Dimensional ◽  
Attachment Site ◽  
Ulnar Collateral Ligament ◽  
Anatomical Study ◽  
Styloid Process ◽  
Dimensional Structure ◽  
Collateral Ligament ◽  
Ulnar Styloid ◽  
Attachment Sites ◽  
Triangular Fibrocartilage

The ligamentous structures of the triangular fibrocartilage complex (TFCC) and their attachments were examined anatomically and histologically using fresh and embalmed cadavers. The TFCC was observed to have a three-dimensional structure consisting of three palmar ligaments — the short radiolunate (SRL), ulnolunate (UL), and ulnotriquetral (UT) ligaments. In addition, the attachment site of the ulnocarpal ligament (UC), which had been previously unknown, was identified. The dorsal components of the TFCC have been previously reported to consist solely of the extensor carpi ulnaris (ECU) subsheath; however, the ligamentous components running from the ulnar styloid process to the triquetrum were found at a layer deeper than the floor of the ECU subsheath. The UC has been reported previously as a two-dimensional structure, but there has been some disagreement as to its attachment sites.2–6,14,15 It is suggested that the dorsal UT ligament should be considered as a separate ligament, based on its different direction and distal attachment site as compared with those of the ulnar collateral ligament (UCL) and ECU subsheath.

Comparison of the Biomechanical Profile of the Intact Ulnar Collateral Ligament with the Modified Jobe and the Docking Reconstructed Elbow

2009 ◽  
Vol 37 (5) ◽  
pp. 974-981 ◽  
Author(s):  
Michael G. Ciccotti ◽  
Sorin Siegler ◽  
John A. Kuri ◽  
John H. Thinnes ◽  
Daniel J. Murphy
Keyword(s):  
Degrees Of Freedom ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Collateral Ligament ◽  
Valgus Stress ◽  
Anterior Portion ◽  
Reconstructive Procedures ◽  
Kinematic Coupling ◽  
Loading System ◽  
4 Degrees Of Freedom

Background The modified Jobe and Docking techniques are commonly used to reconstruct the elbow's ulnar collateral ligament. Hypothesis Valgus laxity and kinematic coupling after these reconstructive procedures are similar to those of the native ulnar collateral ligament. Study Design Controlled laboratory study. Methods Testing was conducted on 10 pairs of cadaver elbows using a 4 degrees of freedom loading system. Subfailure valgus loads were applied to the native elbows at different flexion angles; motion and ligament elongation were measured. The elbows were then loaded to failure in valgus at 90° of flexion. The reconstructive techniques were then applied and testing was repeated. Results Only the resting length of the anterior portion of the ulnar collateral ligament anterior bundle remained isometric throughout range of motion. Valgus laxity was nearly equal for the native and reconstructed ligaments at flexion angles of 90° or higher. However, both reconstructions provided less valgus stability than the native ulnar collateral ligament at low flexion angles. Kinematic coupling decreased with increased flexion for both native and reconstructed ligaments. Conclusion The modified Jobe and Docking techniques reconstruct restraint of the native ulnar collateral ligament to valgus laxity and kinematic coupling at 90° of flexion and higher angles where peak valgus torque is experienced in the throwing elbow. Clinical Relevance Both reconstructions provide valgus stability comparable to that of the native ulnar collateral ligament at 90° and higher, helping to explain their success in treating throwing athletes. Both reconstructions provide less valgus stability than the native ulnar collateral ligament at low flexion angles, suggesting that patients undergoing ulnar collateral ligament reconstruction should be cautioned against activities that provide valgus stress at low elbow flexion angles, such as side-arm throwing. This study suggests caution against overtightening the reconstructions at the common 30° of flexion.

FLUOROSCOPIC ANALYSIS FOR THE ESTIMATION OF IN VIVO ELBOW KINEMATICS: INFLUENCE OF 3D MODEL

2012 ◽  
Vol 12 (03) ◽  
pp. 1250046 ◽  
Author(s):  
LUCA TERSI ◽  
SILVIA FANTOZZI ◽  
RITA STAGNI ◽  
ANGELO CAPPELLO
Keyword(s):  
Cost Function ◽  
Three Dimensional ◽  
Elbow Flexion ◽  
Estimation Algorithm ◽  
Healthy Male Subject ◽  
Distance Map ◽  
3D Fluoroscopy ◽  
Flexion Extension ◽  
Single Bone

The reliable knowledge that model-based three-dimensional (3D) fluoroscopy can provide about in vivo joints kinematics is essential to diagnose orthopedic pathologies, develop new prosthesis, and evaluate clinical procedures. To exploit 3D fluoroscopy for the analysis of elbow kinematics, its use was evaluated considering a single model for the forearm or two different models for the ulna and radius. Active elbow flexion-extension and prono-supination motor tasks of a healthy male subject were acquired by means of fluoroscopy. The 3D bone models were automatically aligned to the relevant projections. The pose estimation algorithm sought the tangency condition of the projection rays with the model surface, minimizing a cost function and exploiting an adaptive distance map. Five iterative guided alignments were performed to avoid the final convergence to a local minimum. The results highlighted the critical alignment of the ulna/radius model, particularly when prono-supination is performed. From the physiological motion patterns and given the values of the cost function, 3D fluoroscopy was proven to be applicable to the analysis of the elbow kinematics when single bone models for the ulna and radius are used.

scholarly journals The ulnar collateral ligament loading paradox between in-vitro and in-vivo studies on baseball pitching (narrative review)

2021 ◽  
Vol 8 (1) ◽  
pp. 19-29
Author(s):  
Bart Van Trigt ◽  
Liset (W) Vliegen ◽  
Ton (Ajr) Leenen ◽  
DirkJan (Hej) Veeger
Keyword(s):  
Ulnar Collateral Ligament ◽  
Narrative Review ◽  
In Vivo Studies ◽  
Collateral Ligament

scholarly journals Biomechanical Comparison of UCL Repair Using Suspensory Fixation Versus UCL Reconstruction

2021 ◽  
Vol 9 (9) ◽  
pp. 232596712110389
Author(s):  
R. Nelson Mead ◽  
Trevor J. Nelson ◽  
Orr Limpisvasti ◽  
Neal S. ElAttrache ◽  
Melodie F. Metzger
Keyword(s):  
Motion Tracking ◽  
Full Range ◽  
Ulnar Collateral Ligament ◽  
Elbow Flexion ◽  
Collateral Ligament ◽  
Repair Technique ◽  
Significant Difference ◽  
Suspensory Fixation ◽  
Fresh Frozen ◽  
Biomechanical Comparison

Background: Medial ulnar collateral ligament (mUCL) repair is growing in popularity as a treatment for younger athletes with mUCL tears. One of the most recent techniques utilizes a collagen-coated suture tape to augment the repair. The most popular repair technique uses a screw for proximal fixation in the humerus. We present an alternative technique that uses suspensory fixation in the proximal humerus. Purpose: To biomechanically compare elbow valgus stability and load to failure of a novel alternative repair technique with suspensory fixation to an mUCL reconstruction. Study Design: Controlled laboratory study. Methods: Eighteen fresh-frozen cadaveric elbows were dissected to expose the mUCL. Medial elbow stability was tested with the mUCL in an intact, deficient—either repaired or reconstructed—state. The repair technique used a suspensory fixation with suture augmentation, and the docking technique was used on all reconstructions. A 3-N·m valgus torque was applied to the elbow, and valgus rotation of the ulna was recorded via motion tracking cameras as the elbow was cycled through a full range of motion. After kinematic testing, specimens were loaded to failure at 70° of elbow flexion. Results: Both ulnar collateral ligament reconstruction and repair restored valgus stability to levels that were not statistically different from intact at all angles of flexion. There was no significant difference in the ultimate torque to failure between repaired and reconstructed mUCLs. Conclusion: There was no significant difference in the valgus strength between the mUCL repair with suspensory fixation and the mUCL reconstruction. Clinical Relevance: Suspensory fixation is an alternative method for proximal fixation in the mUCL without compromising the strength of the construct.

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