Lower back arches under the band pull
The band pulls the arms forward at lockout; engage the core to resist.
Overactive muscles
Erector spinaeLatissimus dorsi
Corrective work
Foam RollLats↗StretchLat stretch (kneeling overhead)↗The band pulls the arms forward at lockout; engage the core to resist.
Upper traps assist the final extension instead of the deltoids pressing tall.