Muscle Conventions, Levers, and Nerve Innervation

fulcrum between load and effort

first class lever

load between fulcrum and effort

second class lever

effort between load and fulcrum

third class lever

anteriorly cross hip and above

flexion

posteriorly cross hip and above

extension

anteriorly cross knee and below

extension

posteriorly cross knee and below

flexion

superior/lateral cross of all joints

abduction

inferior/medial cross of all joints

adduction

horizontal/oblique fibers

rotation

anterior brachial compartment nerve

musculocutaneous

posterior brachial nerve

radial

anterior antebrachial nerve

median and ulnar

posterior antebrachial nerve

radial

anterior thigh nerve

femoral

medial thigh nerve

obturator

posterior thigh nerve

sciatic

anterior leg nerve

deep peroneal

lateral leg nerve

superficial peroneal

superficial posterior leg nerve

tibial

deep posterior leg nerve

tibial