Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers
Abstract Background Flexor digitorum superficialis (FDS) muscle provides dynamic stabilization and medial elbow support for ulnar collateral ligament (UCL). The FDS contraction significantly affects the medial joint distance (MJD) through grip contraction. However, it remains unclear whether FDS act...
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| Format: | Article |
| Language: | English |
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BMC
2020-03-01
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| Series: | Journal of Orthopaedic Surgery and Research |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13018-020-01640-7 |
| _version_ | 1828353531851046912 |
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| author | Shota Hoshika Akimoto Nimura Norimasa Takahashi Hiroyuki Sugaya Keiichi Akita |
| author_facet | Shota Hoshika Akimoto Nimura Norimasa Takahashi Hiroyuki Sugaya Keiichi Akita |
| author_sort | Shota Hoshika |
| collection | DOAJ |
| description | Abstract Background Flexor digitorum superficialis (FDS) muscle provides dynamic stabilization and medial elbow support for ulnar collateral ligament (UCL). The FDS contraction significantly affects the medial joint distance (MJD) through grip contraction. However, it remains unclear whether FDS activity alone contributes to medial elbow stability, or together with the activation of the flexor digitorum profundus during grip contraction, and which finger’s FDS is the main contributor to elbow stability. We investigated the resistive effects of isolated FDS contraction in individual fingers against valgus stress in the elbow joint using stress ultrasonography (US). Methods We investigated 17 healthy males (mean age, 27 ± 5 years). Valgus stress US was performed using the Telos device, with the elbow at 30° flexion. MJD was measured for each arm during 3 separate conditions: at rest (unloaded), under valgus load (50 N) (loaded), and under valgus load with FDS contracted in individual fingers (loaded-contracted). Results MJD was significantly longer when loaded (5.4 ± 0.4 mm) than unloaded (4.1 ± 0.2 mm, P = 0.007) or loaded-contracted (4.6 ± 0.3 mm, P = 0.003) for each finger. When loaded-contracted, MJD differed statistically between the index and ring fingers (P = 0.03) and between the middle and ring fingers (P = 0.04). However, the difference between the index and middle fingers was not statistically significant (P = 0.08). Conclusions Individual FDS contraction, particularly of the index and middle fingers, contributes most to stabilization against valgus stress. Thus, injury care programs should incorporate FDS exercises of these fingers. |
| first_indexed | 2024-04-14T02:09:59Z |
| format | Article |
| id | doaj.art-18a4841b666f45998afd7ef6652f6f70 |
| institution | Directory Open Access Journal |
| issn | 1749-799X |
| language | English |
| last_indexed | 2024-04-14T02:09:59Z |
| publishDate | 2020-03-01 |
| publisher | BMC |
| record_format | Article |
| series | Journal of Orthopaedic Surgery and Research |
| spelling | doaj.art-18a4841b666f45998afd7ef6652f6f702022-12-22T02:18:26ZengBMCJournal of Orthopaedic Surgery and Research1749-799X2020-03-011511610.1186/s13018-020-01640-7Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingersShota Hoshika0Akimoto Nimura1Norimasa Takahashi2Hiroyuki Sugaya3Keiichi Akita4Shoulder & Elbow Service, Funabashi Orthopaedic Sports Medicine & Joint CenterDepartment of Functional Joint Anatomy, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental UniversityShoulder & Elbow Service, Funabashi Orthopaedic Sports Medicine & Joint CenterShoulder & Elbow Service, Funabashi Orthopaedic Sports Medicine & Joint CenterDepartment of Clinical Anatomy, Graduate School of Medical and Dental Science, Tokyo Medical and Dental UniversityAbstract Background Flexor digitorum superficialis (FDS) muscle provides dynamic stabilization and medial elbow support for ulnar collateral ligament (UCL). The FDS contraction significantly affects the medial joint distance (MJD) through grip contraction. However, it remains unclear whether FDS activity alone contributes to medial elbow stability, or together with the activation of the flexor digitorum profundus during grip contraction, and which finger’s FDS is the main contributor to elbow stability. We investigated the resistive effects of isolated FDS contraction in individual fingers against valgus stress in the elbow joint using stress ultrasonography (US). Methods We investigated 17 healthy males (mean age, 27 ± 5 years). Valgus stress US was performed using the Telos device, with the elbow at 30° flexion. MJD was measured for each arm during 3 separate conditions: at rest (unloaded), under valgus load (50 N) (loaded), and under valgus load with FDS contracted in individual fingers (loaded-contracted). Results MJD was significantly longer when loaded (5.4 ± 0.4 mm) than unloaded (4.1 ± 0.2 mm, P = 0.007) or loaded-contracted (4.6 ± 0.3 mm, P = 0.003) for each finger. When loaded-contracted, MJD differed statistically between the index and ring fingers (P = 0.03) and between the middle and ring fingers (P = 0.04). However, the difference between the index and middle fingers was not statistically significant (P = 0.08). Conclusions Individual FDS contraction, particularly of the index and middle fingers, contributes most to stabilization against valgus stress. Thus, injury care programs should incorporate FDS exercises of these fingers.http://link.springer.com/article/10.1186/s13018-020-01640-7Ulnar collateral ligamentUltrasoundFlexor digitorum superficialisOverhead sports |
| spellingShingle | Shota Hoshika Akimoto Nimura Norimasa Takahashi Hiroyuki Sugaya Keiichi Akita Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers Journal of Orthopaedic Surgery and Research Ulnar collateral ligament Ultrasound Flexor digitorum superficialis Overhead sports |
| title | Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers |
| title_full | Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers |
| title_fullStr | Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers |
| title_full_unstemmed | Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers |
| title_short | Valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers |
| title_sort | valgus stability is enhanced by flexor digitorum superficialis muscle contraction of the index and middle fingers |
| topic | Ulnar collateral ligament Ultrasound Flexor digitorum superficialis Overhead sports |
| url | http://link.springer.com/article/10.1186/s13018-020-01640-7 |
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