In my book Parkour Strength Training, I go into detail about the differences between the hard and soft landing techniques (AKA depth drop when used as a strength training exercise). Without going into a long explanation, know that depending on the circumstances of a drop (and your training goals), you may want to stay stiffer and taller in order to rebound quickly (hard landing) or you may want to absorb more deeply and silently (soft landing).
The higher the drop, the more likely the need for fuller compression with your knees flexed beyond 90-degrees. Sometimes you will even need to put your hands down in front of you — between your legs, not outside — for extra support and balance. A good rule for beginners is to aim to arrest your landing squat depth before you break a 90-degree angle with your upper and lower leg. The 90-degree mark is a good and simplified middle ground, in between a true soft and hard landing, for beginners to initially focus on. To learn more about landings for beginners, check out our online course Parkour 101. Intermediate and advanced athletes will likely have the strength, mobility, and control to safely absorb past 90-degrees, but beginners may not yet be ready. See what I’m talking about in this epic and unexpected height drop from time trials champion Dylan Baker:
* * * Note: Despite this method of categorizing soft and hard landings, the difference between each technique is not always clear-cut. Imagine that hard and soft landings are on either end of the landing spectrum. In the middle of this spectrum is some gray area that may vary depending on the athlete and the application of movement.
Soft Landing (Soft Depth Drop)
Focus: Decelerating slowly, silently, & gently.
Kinematics (body shapes & positions): Knee flexion is greater than or equal to 90 degrees (looks more like a full squat), may result in palms touching the ground for balance.
Pros: Minimizing impact, being stealthy and quiet, may be necessary for bigger drops and max jumps.
Cons: Reduces rebounding power, potentially slower transitions, slower times on speed courses.
Hard Landing (Hard Depth Drop)
Focus: Decelerating quickly, rebounding, and/or transitioning with speed & power.
Kinematics: Knee flexion is less than 90 degrees (typically looks more like a quarter squat), palms do not touch the ground.
Pros: More powerful rebounding, potentially faster transitions, faster times on speed courses.
Cons: More impactful, louder, may not be as sustainable for the body.