A1 pulley stretching treats trigger finger: A1 pulley luminal region under digital flexor tendon traction

Yamazaki, Atsuro; Matsuura, Yusuke; Kuniyoshi, Kazuki; Suzuki, Takane; Akasaka, Tomoyo; Ozone, Ei; Matsuyama, Yoshiyuki; Mukai, Michiaki; Yamazaki, Takahiro; Ohara, Takeru; Sasho, Takahisa; Ohtori, Seiji

doi:10.1016/j.clinbiomech.2019.11.018

Cited by 4 publications

(3 citation statements)

References 10 publications

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“…On the basis of this theory, new techniques for preparing raw powders for HDDR that lead to enhanced anisotropy have been reported. 43,44) As described above, anisotropic magnetic powders obtained by the HDDR process are attracting attention as promising magnetic materials for high-speed motors. In addition, in response to the aforementioned demand for high-performance magnets with lower Tb and Dy contents, anisotropic magnetic powders with high coercivity prepared by the HDDR process without the use of heavy rare-earth elements have been reported.…”

Section: Introductionmentioning

confidence: 99%

Relationship between Hydrogen Pressure and Temperature for Recombination Reactions in the HDDR Processing of Ce–Fe–B Alloys

Shimbo,

Horikawa,

Yamazaki

et al. 2023

Mater. Trans.

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In recent years, to reduce manufacturing costs and alleviate the rare-earth supply/demand imbalance in the Nd-Fe-B magnet market, researchers have actively pursued the development of (Nd,Ce)-Fe-B magnets, in which Nd is replaced by Ce. In the present study, we focused on magnetic powders treated by the hydrogenation-disproportionation-desorption-recombination (HDDR) process and explored the relationship between the hydrogen pressure and temperature (P H2 -T curves) in the Ce-Fe-B system, which is essential for the development of (Nd,Ce)-Fe-B magnets. It was confirmed that the disproportionation and recombination reactions of both Ce 2 Fe 14 B and CeFe 2 take place in the Ce-Fe-B system. Furthermore, compared with Nd 2 Fe 14 B, the P H2 -T curve of Ce 2 Fe 14 B was found to be shifted to higher pressure and lower temperature, suggesting a corresponding shift in the HDDR conditions under which good magnetic properties can be obtained.

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Section: Introductionmentioning

confidence: 99%

Relationship between Hydrogen Pressure and Temperature for Recombination Reactions in the HDDR Processing of Ce–Fe–B Alloys

Shimbo,

Horikawa,

Yamazaki

et al. 2023

Mater. Trans.

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“…Upon flexion of the metacarpophalangeal (MP) joint, the active flexor tendon contraction force and counteracting flexor tendon force can generate contact forces that expand the A1 pulley toward the palm. It has been reported that a combination of this “A1 pulley stretch” and the conventional passive extension stretch of the finger for 30 s, 10 times daily for a month, improved pain and triggering during motion in patients with trigger finger [ 19 ]. A cadaveric study reported that A1PLs expanded upon loading of the flexor tendon with the proximal interphalangeal (PIP) and MP joint fixed at a flexion angle [ 19 ].…”

Section: Introductionmentioning

confidence: 99%

“…It has been reported that a combination of this “A1 pulley stretch” and the conventional passive extension stretch of the finger for 30 s, 10 times daily for a month, improved pain and triggering during motion in patients with trigger finger [ 19 ]. A cadaveric study reported that A1PLs expanded upon loading of the flexor tendon with the proximal interphalangeal (PIP) and MP joint fixed at a flexion angle [ 19 ]. This cadaveric study did not include patients with trigger finger, who may have a stiffer and thicker A1 pulley, thereby making it difficult to expand the A1PL [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the first annular pulley stretch effect under isometric contraction of the flexor tendon in healthy volunteers and trigger finger patients using ultrasonography

Tanaka

Uehara

Ryota

et al. 2021

BMC Musculoskelet Disord

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Background Isometric exercises for a flexed finger have been reported to be effective for treating trigger finger as the flexor tendon widens the space under the first annular (A1) pulley towards the palmar destination during the exercise. This study aimed to evaluate the structural changes during the A1 pulley stretch in healthy volunteers and patients with trigger finger using ultrasonography. Methods We enrolled 25 male and 14 female patients (39 middle fingers). The thickness of the subcutaneous tissue (parameter a), A1 pulley (parameter b), and the flexor tendon (parameter c) and the distance between the dorsal surface of the flexor tendon and the palmar surface of the metacarpal head (parameter d) were measured using ultrasonography of the metacarpophalangeal joint of the middle finger flexed at 45° at rest (pattern A) and under isometric contraction of the flexor tendon against an extension force of the proximal interphalangeal joint (pattern B). Results The average differences between patterns A and B in the healthy volunteers were 0.29 mm (parameter a; P = 0.02), 0.017 mm (parameter b; P = 0.63), 0.16 (parameter c; P = 0.26), and 0.41 (parameter d; P = 0.004), and those in patients with trigger finger were 0.22 mm (parameter a; P = 0.23), 0.019 mm (parameter b; P = 0.85), 0.03 mm (parameter c; P = 0.82), and 0.78 mm (parameter d; P < 0.001). The distance between the dorsal side of the A1 pulley and the palmar surface of the metacarpal head was also significantly increased by 0.57 mm (8.2%) in healthy volunteers (P < 0.001) and 0.81 mm (11%) in patients with trigger finger (P < 0.001). Conclusions In this study, the space under the A1 pulley was expanded under isometric contraction of the flexor tendon. These findings support the effectiveness of pulley stretch exercises for the trigger finger condition.

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Trigger Finger

Waldman

2024

Atlas of Common Pain Syndromes

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A1 pulley stretching treats trigger finger: A1 pulley luminal region under digital flexor tendon traction

Cited by 4 publications

References 10 publications

Relationship between Hydrogen Pressure and Temperature for Recombination Reactions in the HDDR Processing of Ce–Fe–B Alloys

Relationship between Hydrogen Pressure and Temperature for Recombination Reactions in the HDDR Processing of Ce–Fe–B Alloys

Evaluation of the first annular pulley stretch effect under isometric contraction of the flexor tendon in healthy volunteers and trigger finger patients using ultrasonography

Trigger Finger

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