We discussed the topic of cramped seating and the dangers that this poses to the passengers when it comes to emergency evacuation in an earlier thread. Here is a very interesting article that addresses this issue. Even John Nance who had mostly positive things to say about the airlines, was critical of seating and the dangers of overcrowding that exist on today's aircraft.

Cramped Seating Can 'Trap' and 'Trip' Passengers During Emergency Evacuation'

More space needed for today's overweight, aging passengers, study concludes

The combination of larger passengers crammed into tightly packed seats could delay emergency evacuation and contribute to potentially fatal embolisms on long flights. Providing more space between seats, and redesigning them to better accommodate persons of widely varying sizes, could have enormous cost implications to the airlines.
A recent study concludes that economy-class passengers are so tightly packed together that they cannot assume a correct "brace" position for emergency landing, and the seats themselves can be obstacles to quick emergency evacuation of the cabin. The current minimum spacing and design standards for transport-category aircraft allow for too-tight seating, and new standards are needed regarding minimum seat width and a minimum area for feet.

For the rest of this article go to the following link:

http://www.aviationtoday.com/reports/crampedseat.htm