When designing a split program, adequate recuperation of the lower back (Erector Spinae muscles and the joints of the thoracic & lumbar spine) must be considered. As with all muscles and joints exercised with moderate to heavy weight, it is necessary to allow the lower back to recuperate at least 48 hours (longer for advanced trainies) before involving it in another workout; directly (as a target muscle) or indirectly (as a synergistic or stabilizer muscle). For this reason, use complementary pairing of exercises within a program:

Examples of complimentary pairing of exercises

Month	Quadriceps & Gluteus Maximus	Hamstrings	Back
A	Squat (Lower Back)	Lying Leg Curl	Dumbbell Bent-over Row
B	Leg Press	Straight Leg Deadlift (Lower Back)	Lever Seated Row
C	Sled Hack Squat	Seated Leg Curl	Cable Seated Row (Lower Back)

To minimize the number of exercises in a workout the Erector Spinae can be can be exercised along with other muscles:

Isotonically	Isometrically
Quadriceps
	Squat
Gluteus Maximus
Stiff-leg Deadlift	Squat Deadlift Straight-back Stiff-leg Deadlift Bent Knee Good-morning Hip Extension
Hamstrings
Glute-Ham Raise Hyper-extension Straight-leg Deadlift	Good-morning Straight-back Straight-leg Deadlift Hip Extension
Back, General
Seated Row	Barbell Bent-over Row Lever Bent-over Row

See other Erector Spinae exercises. Also see other Split Program Design Flaws.