PMID- 32238189
OWN - NLM
STAT- MEDLINE
DCOM- 20210107
LR  - 20210107
IS  - 1749-799X (Electronic)
IS  - 1749-799X (Linking)
VI  - 15
IP  - 1
DP  - 2020 Mar 30
TI  - Valgus stability is enhanced by flexor digitorum superficialis muscle contraction 
      of the index and middle fingers.
PG  - 121
LID - 10.1186/s13018-020-01640-7 [doi]
LID - 121
AB  - 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 degrees  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.
FAU - Hoshika, Shota
AU  - Hoshika S
AD  - Shoulder & Elbow Service, Funabashi Orthopaedic Sports Medicine & Joint Center, 
      Funabashi, Chiba, Japan.
AD  - Department of Clinical Anatomy, Graduate School of Medical and Dental Science, 
      Tokyo Medical and Dental University, Tokyo, Japan.
FAU - Nimura, Akimoto
AU  - Nimura A
AD  - Department of Functional Joint Anatomy, Graduate School of Medical and Dental 
      Sciences, Tokyo Medical and Dental University, Tokyo, Japan. 
      nimura.orj@tmd.ac.jp.
FAU - Takahashi, Norimasa
AU  - Takahashi N
AD  - Shoulder & Elbow Service, Funabashi Orthopaedic Sports Medicine & Joint Center, 
      Funabashi, Chiba, Japan.
FAU - Sugaya, Hiroyuki
AU  - Sugaya H
AD  - Shoulder & Elbow Service, Funabashi Orthopaedic Sports Medicine & Joint Center, 
      Funabashi, Chiba, Japan.
FAU - Akita, Keiichi
AU  - Akita K
AD  - Department of Clinical Anatomy, Graduate School of Medical and Dental Science, 
      Tokyo Medical and Dental University, Tokyo, Japan.
LA  - eng
PT  - Journal Article
DEP - 20200330
PL  - England
TA  - J Orthop Surg Res
JT  - Journal of orthopaedic surgery and research
JID - 101265112
SB  - IM
MH  - Adult
MH  - Collateral Ligament, Ulnar/diagnostic imaging/*physiology
MH  - Elbow Joint/diagnostic imaging/*physiology
MH  - Female
MH  - Fingers/diagnostic imaging/*physiology
MH  - Hand Strength/*physiology
MH  - Humans
MH  - Male
MH  - Muscle Contraction/*physiology
MH  - Muscle, Skeletal/diagnostic imaging/*physiology
MH  - Young Adult
PMC - PMC7110663
OTO - NOTNLM
OT  - Flexor digitorum superficialis
OT  - Overhead sports
OT  - Ulnar collateral ligament
OT  - Ultrasound
COIS- The authors declare that they have no competing interests
EDAT- 2020/04/03 06:00
MHDA- 2021/01/08 06:00
PMCR- 2020/03/30
CRDT- 2020/04/03 06:00
PHST- 2020/01/17 00:00 [received]
PHST- 2020/03/20 00:00 [accepted]
PHST- 2020/04/03 06:00 [entrez]
PHST- 2020/04/03 06:00 [pubmed]
PHST- 2021/01/08 06:00 [medline]
PHST- 2020/03/30 00:00 [pmc-release]
AID - 10.1186/s13018-020-01640-7 [pii]
AID - 1640 [pii]
AID - 10.1186/s13018-020-01640-7 [doi]
PST - epublish
SO  - J Orthop Surg Res. 2020 Mar 30;15(1):121. doi: 10.1186/s13018-020-01640-7.