Selective Activation of Thoracic Extensor Muscles during 3 Different Trunk Extensor Strengthening Exercise

Background Although there are many exercises to selectively strengthen the thoracic extensor, general trunk extensor strengthening exercises lead to pain and excessive lumbar extension. Purpose We investigated the most effective exercise among three thoracic extensor strengthening exercises (active prone thoracic extension, active prone thoracic hyper-extension, and active sitting thoracic extension) based on selective activity of the thoracic spine extensors. Study design Comparative, repeated measures design. Methods Sixteen healthy participants performed three thoracic extensor strengthening exercises. Electromyograph (EMG) activity was measured in the longissimus thoracis (LT), iliocostalis thoracis (ICT), and iliocostalis lumborum (ICL) muscles. Results The ICT/ICL and LT/ICL composition ratios were greatest in active sitting thoracic extension compared to other exercises. Conclusions We recommend active sitting thoracic extension exercise for selective strengthening of the thoracic spine extensor.