Theory:

The advantages of walking straight are as follows:
Bipedal locomotion has the advantage of allowing the hands to hold tools. Our forefathers used their free hands to hold tools and even babies long before we did.
 
Scene illustrating a few of the benefits of upright walking l_0.jpg
A scene depicting some of the advantages of upright walking
  
As environment and climatic condition changed, walking on two legs helped early humans survive by:
  • It frees up hands for holding tools and small children.
  • It enhances our capacity to de-stress.
  • It allowed our forefathers to see through the tall grasses.
  • It enables us to fly long distances, picking fruits and other foods from low-lying branches much more accessible.
  • They are allowing hands to be freed up to hold food, equipment, or infants.
  • Early humans were able to look larger and more imposing as a result of this ability.
Disadvantages of walking straight:
Back pain and other skeletal disorders are relatively standard in modern humans as a result of walking upright. Lower back pain, slipped discs, arthritis in the hips and knees, and collapsed foot arches can result from putting all of our weight on just two limbs.