Abstract
Context: A relationship between low back pain (LBP) and increased lumbar paraspinal muscular fatigue rate has been established. LBP and lumbar paraspinal fatigue have been shown to decrease quadriceps activation. The response of other lower extremity muscles following lumbar paraspinal fatigue is unknown. Objective: To determine the change in vastus medialis, soleus, and peroneal longus activation following lumbar paraspinal fatigue in individuals with and without a history of LBP. Conclusions: The soleus was facilitated following paraspinal fatigue regardless of group. Contrary to current literature, there was no change in motoneuron pool excitability in the quadriceps or peroneals. The change in soleus activation indicates that low back fatigue may affect postural muscles distal to the site of fatigue even if a change is not seen proximally in the kinetic chain.