Squats activate the lower back more than deadlifting

[Johan]

I found this gem on Bret Contreras blog

http://www.ncbi.nlm.nih.gov/pubmed/18076231

Electromyographic (EMG) activity was measured from the lower abdominals (LA), external obliques (EO), upper lumbar erector spinae (ULES), and lumbar-sacral erector spinae (LSES) muscle groups. Results indicated that the LSES EMG activity during the 80% 1RM squat significantly exceeded 80% 1RM deadlift LSES EMG activity by 34.5%. The LSES EMG activity of the 80% 1RM squat also exceeded the body weight squat, deadlift, superman, and sidebridge by 56, 56.6, 65.5, and 53.1%, respectively. The 80% 1RM deadlift ULES EMG activity significantly exceeded the 80% 1RM squat exercise by 12.9%.

[Johan]

I would guess it would be wildly different for different people. For me it would be of the chart Because whenever I approach my 1rm my form goes to hell in no time. Stiff leg, bent back and pulling it with pure retard strength. My back feels iffy for days after heavy deads, thats why I have excluded them from my routine.

Not sure how it would be like for those "built to deadlift" that seem to pull easily and naturally, but I have never seen anyone maintain a good flat or arched back when pulling close to 1rm. Seems like its either slightly bent or a lot bent, but never perfect?

What do you think mate?