Occupational Therapy Department, Faculty of Allied Health Sciences, Kuwait University, Kuwait.
Radiology Department, Al-Razi Orthopedic Hospital, MOH Kuwait, Kuwait.
J Hand Ther. 2022 Apr-Jun;35(2):261-266. doi: 10.1016/j.jht.2022.03.003. Epub 2022 Apr 30.
During finger flexion, the tendons of flexor digitorum profundus migrate proximally, along with their attached lumbrical muscles. This incursion was suggested to extend into the Carpal Tunnel. Ultrasonographic imaging can be used to assess in vivo soft tissue behavior and incursion.
To clinically quantify the lumbrical muscles incursion in different finger positions.
Cross sectional, observational study.
The lumbricals of 20 healthy adults with no history of hand injuries were evaluated with neuromuscular ultrasound imaging (n = 160 lumbricals). The lumbrical muscles migration was measured as the participants actively moved their fingers from full extension to 50% flexion, and 100% flexion.
Of the 160 lumbricals measures, the incursion occurred at 18.1% of fingers at 50% finger flexion, and increased to 79.4% during full finger flexion. The lumbricals migrated a total of 2.99 cm after full finger flexion, and ended up 0.76 cm (SD = 0.86 cm) inside the Carpal Tunnel. The metacarpophalangeal joint range of motion of the index finger at the point where the lumbricals entered the distal border of the Transverse Carpal Ligament was 84.4° (SD = 6.8°). The Carpal Tunnel cross-sectional area during finger extension was 1.68 (0.35) cm, and increased to 1.81 (0.33) cm after full finger flexion.
This study showed direct evidence of lumbrical incursion into the Carpal Tunnel during finger flexion. The cross-sectional area of the Carpal Tunnel increased during full finger flexion in comparison to full finger extension, supplementing the evidence of increase content within the Carpal Tunnel. The findings of this study have significant clinical implications for the conservative treatment of the Capral Tunnel Syndrome.
在手指弯曲过程中，指深屈肌腱及其附着的蚓状肌向近端迁移。这种侵入被认为延伸到了腕管。超声成像可用于评估活体软组织的行为和侵入。
临床量化不同手指位置下蚓状肌的侵入。
横断面观察性研究。
对 20 名无手部受伤史的健康成年人的蚓状肌进行神经肌肉超声成像评估（n=160 个蚓状肌）。在参与者主动将手指从完全伸展到 50%弯曲和 100%弯曲的过程中，测量蚓状肌的迁移。
在 160 个蚓状肌测量中，50%手指弯曲时有 18.1%的手指发生侵入，在完全手指弯曲时增加到 79.4%。手指完全弯曲后，蚓状肌总共迁移了 2.99 厘米，最终进入腕管内 0.76 厘米（SD=0.86 厘米）。蚓状肌进入横腕韧带远端边界时，食指的掌指关节活动度为 84.4°（SD=6.8°）。手指伸展时腕管的横截面积为 1.68（0.35）cm，完全弯曲手指后增加到 1.81（0.33）cm。
本研究直接证明了手指弯曲时蚓状肌侵入腕管。与完全伸展手指相比，完全弯曲手指时腕管的横截面积增加，补充了腕管内内容物增加的证据。本研究的结果对腕管综合征的保守治疗具有重要的临床意义。
