Muscle and tendon size relationships in a paralyzed chick embryo model of clubfoot.
Clubfoot is a birth defect that may be related to muscle weakness or imbalance. The purpose of this study was to examine the relationships among muscle and tendon size and embryonic motility in a paralyzed chick embryo model of clubfoot and arthrogryposis. Decamethonium bromide, a neuromuscular blocking agent, was administered to a series of embryos in five dosage groups, producing a cohort of embryos with various degrees of paralysis and atrophy of tendons and muscle. Embryonic movement frequency was monitored, and after death in late gestation, the cross-sectional areas of the calf musculature and the gastrocnemius tendon proximal to the ankle were measured histologically. Significant correlations were found between embryonic motility and both muscle (r2 = 0.52) and tendon (r2 = 0.77) areas. In addition, a significant correlation (r2 = 0.74) was found between muscle and tendon areas, suggesting that a measurement of one may be used to predict the other.
Germiller
J A
JA
Section of Orthopaedic Surgery, University of Michigan, Ann Arbor, USA.
Lerner
A L
AL
Pacifico
R J
RJ
Loder
R T
RT
Hensinger
R N
RN
D000818:Animals; D002642:Chick Embryo; D003025:Clubfoot / Q000209:etiology*; D003650:Decamethonium Compounds / Q000008:administration & dosage; D004195:Disease Models, Animal; D006614:Hindlimb / Q000473:pathology*; D009068:Movement; D018482:Muscle, Skeletal / Q000473:pathology*; D009133:Muscular Atrophy / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D009466:Neuromuscular Blocking Agents / Q000008:administration & dosage; D010243:Paralysis / Q000139:chemically induced / Q000473:pathology* / Q000503:physiopathology; D013710:Tendons / Q000473:pathology*
D003650:Decamethonium Compounds; D009466:Neuromuscular Blocking Agents; C033019:decamethonium