Effect of Repetitive Loading on the Wrist of Young Rabbits

1994 ◽  
pp. 17-23
Author(s):  
Hideo Kawai ◽  
Tsuyoshi Murase ◽  
Takashi Masatomi ◽  
Masakazu Murai ◽  
Ryoichi Shibuya ◽  
...  
Keyword(s):  
Repetitive Loading

Composite Prestressed Concrete Beams Under Repetitive Loading

PCI Journal ◽  
1958 ◽  
Vol 3 (4) ◽  
pp. 19-27
Author(s):  
A. M. Ozell ◽  
J. F. Diniz
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Repetitive Loading

The Characteristics of Prestressed Concrete Under Repetitive Loading

PCI Journal ◽  
1956 ◽  
Vol 1 (3) ◽  
pp. 7-16
Author(s):  
C.E. Ekberg, Jr.
Keyword(s):  
Prestressed Concrete ◽  
Repetitive Loading

A COMPARATIVE BIOMECHANICAL STUDY OF THE LOOPED SQUARE SLIP KNOT AND THE SIMPLE SURGICAL KNOT

Hand Surgery ◽  
2006 ◽  
Vol 11 (01n02) ◽  
pp. 93-99 ◽  
Author(s):  
Surut Jianmongkol ◽  
Geoffrey Hooper ◽  
Weerachai Kowsuwon ◽  
Tala Thammaroj
Keyword(s):  
Ultimate Strength ◽  
Hand Surgery ◽  
Biomechanical Properties ◽  
Biomechanical Study ◽  
Skin Closure ◽  
Significant Difference ◽  
Mode Of Failure ◽  
Repetitive Loading ◽  
Slip Knot

The looped square slip knot was introduced as a technique for skin closure to avoid the use of sharp instruments in suture removal after hand surgery. We compared the biomechanical properties of this knot with the simple surgical square knot. The ultimate strength of the looped square slip knot was significantly (p = 0.015) higher than the simple surgical knot. There was no significant difference between the two knots in mode of failure. Knot slippage or suture breakage did not occur in any samples when testing security by repetitive loading. Therefore, the looped square slip knot is a safe and convenient alternative to the two-throw surgical knot for use in hand surgery.

Snapping thumb: a rare case of stenosing tenosynovitis of the extensor pollicis longus tendon

2021 ◽  
Vol 14 (6) ◽  
pp. e241306
Author(s):  
Andrea Lund ◽  
Pelle Hanberg ◽  
Anders Ditlev Foldager-Jensen ◽  
Maiken Stilling
Keyword(s):  
Rare Case ◽  
Diagnostic Tools ◽  
Extensor Pollicis Longus ◽  
The Third ◽  
Stenosing Tenosynovitis ◽  
Repetitive Loading ◽  
Extensor Compartment ◽  
Extensor Pollicis Longus Tendon ◽  
Surgical Release

Tenosynovitis of the extensor pollicis longus (EPL) is rarely reported in patients without rheumatoid arthritis but may lead to thumb snapping as a consequence of EPL stenosing tenosynovitis.This case presents painful thumb snapping that developed after a wrist trauma and repetitive loading. Ultrasound and MRI were used as diagnostic tools, before surgical release of the EPL in the third extensor compartment was performed. Neither EPL tenosynovitis nor thumb snapping were found at follow-up.

Recurrence of Scaphoid Stress Fracture: A Case Report

2021 ◽  
Author(s):  
Nick A. Johnson ◽  
Tom Kurien ◽  
Tracy C. Horton
Keyword(s):  
Case Report ◽  
Stress Fracture ◽  
Stress Fractures ◽  
Case Description ◽  
Male Athletes ◽  
Repetitive Loading ◽  
High Level ◽  
Optimum Management ◽  
Prevention Of Recurrence ◽  
Early Fixation

Abstract Background Scaphoid stress fractures are rare and typically present in young, elite male athletes. Due to the infrequency in which these injuries are encountered, the optimum management is not established. Case Description We present the case of a 20-year-old male gymnast with bilateral stress fractures of the scaphoid waist. Following conservative treatment, clinical and radiological signs of union were seen bilaterally. Eight months after return to normal activities, a unilateral recurrence of the stress fracture occurred. This was successfully treated with internal fixation and bone grafting. Literature Review Scaphoid stress fractures are most frequently seen in gymnasts but also occur in participants of other sports involving repetitive loading of an extended wrist. This action conveys force predominantly through the waist of the scaphoid. Most case studies have reported high union rates, whether treated operatively or conservatively, and the patients returned to high-level sport with no further problems. Stress fracture recurrence has been reported in other bones such as the metatarsal and tibia but never before in the scaphoid. Our case is unusual in that the patient suffered ongoing problems due to a recurrence of the scaphoid stress fracture after returning to normal activities. Clinical Relevance Clinicians should be aware that scaphoid stress fracture recurrence can occur, counsel patients accordingly, and remain vigilant after apparent union. We would recommend early fixation to allow a quicker return to function and prevention of recurrence.

scholarly journals Bivalves rapidly repair shells damaged by fatigue and bolster strength

2021 ◽  
Vol 224 (19) ◽  
Author(s):  
R. L. Crane ◽  
J. L. Diaz Reyes ◽  
M. W. Denny
Keyword(s):  
Shell Growth ◽  
Fatigue Loading ◽  
Epifluorescence Microscopy ◽  
Mytilus Californianus ◽  
Environmental Threats ◽  
Rapid Repair ◽  
Shell Deposition ◽  
Repetitive Loading ◽  
Plastic Changes ◽  
Mussel Shells

ABSTRACT Hard external armors have to defend against a lifetime of threats yet are traditionally understood by their ability to withstand a single attack. Survival of bivalve mollusks thus can depend on the ability to repair shell damage between encounters. We studied the capacity for repair in the intertidal mussel Mytilus californianus by compressing live mussels for 15 cycles at ∼79% of their predicted strength (critically fracturing 46% of shells), then allowing the survivors 0, 1, 2 or 4 weeks to repair. Immediately after fatigue loading, mussel shells were 20% weaker than control shells that had not experienced repetitive loading. However, mussels restored full shell strength within 1 week, and after 4 weeks shells that had experienced greater fatiguing forces were stronger than those repetitively loaded at lower forces. Microscopy supported the hypothesis that crack propagation is a mechanism of fatigue-caused weakening. However, the mechanism of repair was only partially explained, as epifluorescence microscopy of calcein staining for shell deposition showed that only half of the mussels that experienced repetitive loading had initiated direct repair via shell growth around fractures. Our findings document repair weeks to months faster than demonstrated in other mollusks. This rapid repair may be important for the mussels’ success contending with predatory and environmental threats in the harsh environment of wave-swept rocky coasts, allowing them to address non-critical but weakening damage and to initiate plastic changes to shell strength. We highlight the significant insight gained by studying biological armors not as static structures but, instead, as dynamic systems that accumulate, repair and respond to damage.

Aluminum foot insoles reduce plantar forefoot pressure and increase foot comfort for motorcyclists

2018 ◽  
Vol 42 (6) ◽  
pp. 606-611 ◽  
Author(s):  
Israel Casado-Hernández ◽  
Ricardo Becerro-de-Bengoa-Vallejo ◽  
Daniel López-López ◽  
Antonio Gómez-Bernal ◽  
Marta Elena Losa-Iglesias
Keyword(s):  
Clinical Trial ◽  
Plantar Pressure ◽  
Clinical Relevance ◽  
Ethylene Vinyl Acetate ◽  
Maximum Pressure ◽  
Foot Pain ◽  
Foot Pressure ◽  
First Metatarsal ◽  
Repetitive Loading ◽  
And Control

Background: Foot pain and paresthesia are common in cycling, due to plantar pressure and repetitive loading. Objectives: The aim was to investigate the effect of foot insoles on plantar pressure of the foot in motorcycling, as well as self-reported comfort. Study design: A randomized crossover clinical trial. Methods: A flexible foot pressure mat (GP MobilData WiFi® Gebiomized®) with different sizes was utilized. Results: Maximum pressure values occurred predominantly in the hallux with 4.90 ± 1.19 N/cm2, followed by second and third metatarsal areas with 4.57 ± 0.73 N/cm2, followed by the first metatarsal area with 4.30 ± 0.96 N/cm2, and followed by the fourth and fifth metatarsal areas with 3.22 ± 0.89 N/cm2 when using the control foot insole and using aluminum foot insole, which reduces maximum pressure to 1.55 ± 0.34, 1.56 ± 0.75, 1.09 ± 0.43, and 1.07 ± 0.59 N/cm2, respectively ( p < 0.001), with an effect size of 3.828, 4.067, 4.315, and 2.847, respectively. Conclusion: The use of an aluminum foot insole significantly reduced maximum pressure during motorcycling. Clinical relevance In this study, an aluminum insole in a motorcycling boot was shown to decrease maximum pressure on the foot. Comfort was significantly higher than that from ethylene vinyl acetate or commercial boot inserts. This increased comfort and decreased pressure should result in increased safety and control for motorcyclists.

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