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Stiffness and Endurance of a Locking Compression Plate Fixed on Fractured Femur

Chaosuan Kanchanomai, Panurungsit Muanjan, and Vajara Phiphobmongkol

The effects of locking screw position (long column fixation—long distance between the nearest screws to the fracture—and short column fixation—short distance between the nearest screws to the fracture) and fracture gap size (1-mm and 8-mm transverse fracture gap) on stiffness and fatigue of fractured femur fixed with a locking compression plate (LCP) were biomechanically evaluated. The stiffness of 1-mm fracture gap models and that of intact femoral model were in the range of 270–284 N/mm, while those of 8-mm fracture gap models were significantly lower (155–170 N/mm). After 1,000,000 cycles of loading, no fracture of LCP of 1-mm fracture gap models fixed in either long column or short column fashions occurred. On the other hand, the complete fractures of LCPs of 8-mm fracture gap models fixed in long column and short column fashions occurred after 51,500 and 42,000 cycles of loading, respectively. These results suggest that the full weight loading may be allowed for the patient with 1-mm transverse femoral fracture fixed with an LCP. On the other hand, the full load of walking should be avoided for the patient with 8-mm transverse femoral fracture fixed with an LCP before adequate healing.

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The Effect of Foot Position and Lean Mass on Jumping and Landing Mechanics in Collegiate Dancers

Chris J. Alfiero, Ann F. Brown, Youngmin Chun, Alexandra Holmes, and Joshua P. Bailey

(vGRF) during landing by increasing joint angular displacement which decreases joint stiffness during a saut de chat 16 (a jump or leap where the dancer lands on the leg opposite the takeoff leg). Kulig et al 16 observed a decrease in knee stiffness and greater knee angular displacement compared with

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A Comparative Analysis of the Center of Gravity and Center of Pressure Trajectory Path Lengths in Standing Posture: An Estimation of Active Stiffness

Olivier Caron, Thierry Gélat, Patrice Rougier, and Jean-Pierre Blanchi

The center of foot pressure (CP) motions, representing the net neuromuscular control, was compared to the center of gravity (CG) motions, representing the net performance. The comparison focused on the trajectory path length parameter along the mediolateral and antero-posterior axes because these two variables depend on amplitude versus frequency relationship. This relationship was used to evaluate the CG motions based on the CP motions. Seven subjects stood still on a force plate with eyes open and eyes closed. The results showed that the ratio of (CP – CG)/CP trajectory path length was personal for each subject. These results suggest different levels of passive (ligaments, elastic properties) and active (reflex activity) stiffness. For some subjects, this ratio was significantly lower for the eyes open condition than for the eyes closed condition, indicating a decrease of the active stiffness for the eyes open condition. Therefore, a CG – CP comparative analysis appeared helpful in understanding the control of balance and necessary to quantify the subjects’ net performance.

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Association of Gastrocnemius Muscle Stiffness With Passive Ankle Joint Stiffness and Sex-Related Difference in the Joint Stiffness

Kentaro Chino and Hideyuki Takahashi

Stiffness is a mechanical measure of a material elasticity defined as the resistance of a material to elongation: greater stiffness means that the material offers greater resistance to a given elongation. 1 , 2 Passive joint stiffness is quantified according to the slope of joint angle

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Comparison of the Immediate Effect of Petrissage Massage and Manual Lymph Drainage Following Exercise on Biomechanical and Viscoelastic Properties of the Rectus Femoris Muscle in Women

Nilüfer Kablan, Nuray Alaca, and Yaşar Tatar

closely related to overuse and overtraining injuries, and abnormal stiffness increase was noted to cause muscle pain, microinjuries, and abnormal tissue repair responses. 4 Therefore, gaining insight into the intrinsic properties of the muscle is needed, not only for the evaluation of healthy tissue, but

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Influence of Badminton Practice on Age-Related Changes in Patellar and Achilles Tendons

Alfredo Bravo-Sánchez, Pablo Abián, Filipa Sousa, Fernando Jimenez, and Javier Abián-Vicén

, 2013 ). In addition, mechanical properties also show adaptations to the training programs, with trained tendons presenting higher stiffness than untrained ones ( Kubo et al., 2010 ). Moreover, there are many age-related changes in cellular and vascular tendon properties ( Hess, 2010 ), which induce

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Older Adults Overcome Reduced Triceps Surae Structural Stiffness to Preserve Ankle Joint Quasi-Stiffness During Walking

Rebecca L. Krupenevich, William H. Clark, Gregory S. Sawicki, and Jason R. Franz

output in walking is generated through the complex interaction between neural drive, triceps surae muscle contractile behavior, and series elastic response from the Achilles tendon. 3 , 4 Ankle joint quasi-stiffness, defined as the slope of the ankle moment–angle relation, 5 is a function of all active

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Inhomogeneous and Anisotropic Mechanical Properties of the Triceps Surae Aponeuroses in Older Adults: Relationships With Muscle Strength and Walking Performance

Xiyao Shan, Pavlos Evangelidis, Takaki Yamagishi, Shun Otsuka, Fumiko Tanaka, Shigenobu Shibata, and Yasuo Kawakami

not clear to date. Supersonic shear imaging (SSI), a recently emerging technique to measure the propagation speed of ultrasonic shear wave, has been used to assess soft tissue stiffness ( Bercoff, Tanter, & Fink, 2004 ; Cortes, Suydam, Silbernagel, Buchanan, & Elliott, 2015 ; Martin et al., 2015

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Effects of Collagen and Exercise on Tendon Properties and Pain: A Critically Appraised Topic

Kylie S. Boldt, Bernadette L. Olson, and Ryan M. Thiele

as best evidence and selected for inclusion in this CAT. • Achilles tendon properties included cross sectional area, thickness, microvascularity and stiffness. • Achilles tendon function was taken as a subjective or objective measure. Table 1 Summary of Study Designs of Articles Retrieved Level of

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Chronic Standing Desk Use and Arterial Stiffness

Ian M. Greenlund, Piersan E. Suriano, Steven J. Elmer, Jason R. Carter, and John J. Durocher

or more hours per day compared with 5 or less hours per day. 4 The relation between sedentary behavior and CVD is complex. Sedentary behavior is shown to increase arterial stiffness and is a known contributor to hypertension and CVD. 5 , 6 Clearly, a reduction in sedentary time and replacement with