Medicine and Health Sciences Commons^™

Current Concepts Of Muscle And Tendon Adaptation To Strength And Conditioning, Jason Brumitt, Tyler Cuddeford

Faculty Publications - College of Physical Therapy

Injuries to the muscle and/or associated tendon(s) are common clinical entities treated by sports physical therapists and other rehabilitation professionals. Therapeutic exercise is a primary treatment modality for muscle and/or tendon injuries; however, the therapeutic exercise strategies should not be applied in a “one-size-fits-all approach”. To optimize an athlete’s rehabilitation or performance, one must be able to construct resistance training programs accounting for the type of injury, the stage of healing, the functional and architectural requirements for the muscle and tendon, and the long-term goals for that patient. The purpose of this clinical commentary is to review the muscular and …

Altered Tendon Characteristics And Mechanical Properties Associated With Insertional Achilles Tendinopathy, Ruth L. Chimenti, Adolph S. Flemister, Joshua Tome, James M. Mcmahon, Marie A. Flannery, Ying Xue, Jeff R. Houck

Faculty Publications - College of Physical Therapy

Study Design: Case-control laboratory study.

Objectives: To compare tendon characteristics (shape, composition) and mechanical properties (strain, stiffness) on the involved side of participants with insertional Achilles tendinopathy (IAT) to the uninvolved side and to controls, and to examine if severity of tendon pathology is associated with severity of symptoms during function.

Background: Despite the severity and chronicity of IAT, the quality of theoretical evidence available to guide the development of exercise interventions is low. While tendon pathology of midportion Achilles tendinopathy has been described, there are few studies specific to IAT.

Methods: Twenty individuals with unilateral IAT and 20 age- …

Influence Of Tendon Tears On Ultrasound Echo Intensity In Response To Loading, Kayt E. Frisch, David Marcu, Geoffrey S. Baer, Darryl G. Thelen, Ray Vanderby

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Acoustoelastic (AE) ultrasound image analysis is a promising non-invasive approach that uses load-dependent echo intensity changes to characterize stiffness of tendinous tissue. The purpose of this study was to investigate whether AE can detect localized changes in tendon stiffness due to partial and full-thickness tendon tears. Ovine infraspinatus tendons with different levels of damage (Intact, 33%, 66% and full thickness cuts initiated on the articular and bursal sides) were cyclically loaded in a mechanical testing system while cine ultrasound images were recorded. The load-induced changes in echo intensity on the bursal and articular side of the tendon were determined. Consistent …

The Influence Of Partial And Full Thickness Tears On Infraspinatus Tendon Strain Patterns, Kayt E. Frisch, David Marcu, Geoffrey S. Baer, Darryl G. Thelen, Ray Vanderby

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Tears on the bursal and articular sides of the rotator cuff tendons are known to behave differently and strain is thought to play a role in this difference. This study investigates the effect of tear location on the changes in three strain measurements (grip-to-grip, insertion, and mid-substance tissue) in a sheep infraspinatus tendon model during axial loading. We introduced a 14mm wide defect near the insertion from either the articular or bursal side of the tendon to three depths (3 mm, 7mm & full) progressively. For each condition, tendons were sinusoidally stretched (4% at 0.5 Hz) while insertion and midsubstance …

Quantification Of Collagen Organization Using Fractal Dimensions And Fourier Transforms, Kayt E. Frisch, Sarah E. Duenwald-Kuehl, Hirohito Kobayashi, Connie S. Chamberlain, Roderic S. Lakes, Ray Vanderby Jr.

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Collagen fibers and fibrils that comprise tendons and ligaments are disrupted or damaged during injury. Fibrillogenesis during healing produces a matrix that is initially quite disorganized, but remodels over time to resemble, but not replicate, the original roughly parallel microstructure. Quantification of these changes is traditionally a laborious and subjective task. In this work we applied two automated techniques, fast Fourier transformation (FFT) and fractal dimension analysis (FA) to quantify the organization of collagen fibers or fibrils. Using multi-photon images of collagen fibers obtained from rat ligament we showed that for healing ligaments, FA differentiates more clearly between the different …

Ultrasound Echo Is Related To Stress And Strain In Tendon, Sarah Duenwald, Hirohito Kobayashi, Kayt E. Frisch, Roderic Lakes, Ray Vanderby Jr.

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

The mechanical behavior of tendons has been well studied in vitro. A noninvasive method to acquire mechanical data would be highly beneficial. Elastography has been a promising method of gathering in vivo tissue mechanical behavior, but it has inherent limitations. This study presents acoustoelasticity as an alternative ultrasound-based method of measuring tendon stress and strain by reporting a relationship between ultrasonic echo intensity (B-mode ultrasound image brightness) and mechanical behavior of tendon in vitro. Porcine digital flexor tendons were cyclically loaded in a mechanical testing system while an ultrasonic echo response was recorded. We report that echo intensity …