Vibram Five Fingers KSO Review for Forefoot Running

Minimalist running shoes do more than just strengthen the feet by actively engaging the foot muscles; they are also beneficial in so many capacities! One of the best, most important contributions of minimalist running shoes, like the VFF KSO, or the Vibram Five Fingers KSO, is ground-feel, or sensory feedback at the feet which is a main lever of mechanical and balance control, creating more balanced mechanics during running AND when you can feel the ground, your forefoot strike will become more easily sustainable during running, which may give you an economical opportunity to perform better.

In that regard, below is my Vibram Five Fingers KSO Review for forefoot running where I discuss the advantages of the shoe, its specifications, how it contrasts with other Vibram running shoes as well as other minimalist running shoes and its essential role in helping you coordinate a more effective forefoot strike landing during running. Not to mention, the KSO was voted the most popular out of all other Vibram models for its versatility.

Vibram Five Fingers KSO Review for Forefoot Running
Turns out that the old advice on running shoes isn’t true: the more cushioning, the better and safer you will run. According to new reports, this is far from true. Now, runners are advised to run in more barefoot-feeling footwear because the thin sole sends form-correcting signals through the feet, helping bring together much-needed balance control and softer footfalls, like forefoot striking, not heel strike during running.
Vibram Five Fingers KSO Review for Forefoot Running
The Vibram Five Finger KSO is given top marks for its flexibility and for its top-notch ground-feel resolution, allowing for better self-monitoring of your foot strike pattern and intensity which forms the foundations of sturdier, more balanced and softer footfalls during running.

Vibram Five Fingers KSO Review for Forefoot Running

The Vibram Five Fingers KSO has a 3.5 mm smooth rubber outsole that provides a wide scope of sensory input and awareness, enabling you to make more proactive efforts in avoiding heel strike during running, which in turn, plays an essential role in deterring harmful impacts away from the knee and hips.

I’m also a big fan of the Velcro single hook and loop closure which helps lock the shoe snug, but not too tightly, on to your foot, giving an overall easily adjustable, dynamic fit, that also stops debris from entering. 

Vibram Five Fingers KSO Review for Forefoot Running
Durable, versatile upper makes for great armor for mud and trail running. The upper materials are made of abrasion-resistant, stretchy polyamide fibers that dries fast and is breathable, letting in enough airflow to keep your feet cool during the summer.

Other notable features of the Vibram KSO’s:

  • Abrasion-resistant stretchy, supple nylon that’s form-fitting and durable enough to handly tricky terrain and muddy conditions 
  •  3.5mm smooth rubber outsole is non-marking
  • Razor-sipped tread pattern is somewhat grippy on wet surfaces, but better for drier surfaces

Vibram Five Fingers KSO Review for Forefoot Running

Vibram Five Finger KSO Review for Forefoot Running
The outsole of the Vibram KSO is flexible, pliable and light, not to mention very tough and responsive on all kinds of terrain.
  • Flat, zero-drop heel height, meaning no mechanical interference during the heel-lowering phase of the forefoot strike, allowing for more elastic energy storage in the Achilles tendon
Vibram Five Fingers KSO Review
When I’m not barefoot, the Vibram KSO is my choice for speed-work! Why? Because it rides soft and light, not heavy and clunky like the traditional running shoe. The KSO’s flat, zero-drop design makes it easier to mount on your forefoot and avoid a forceful heel strike, which in turn, has an enormous protective effect on the knee and elsewhere on the body.
  • Low shaft height; fits just below the ankle, but higher up the ankle as compared with the Vibram KSO EVO
  • The structural design of the upper is literally tailored to keep debris out. Vibram calls the structure the “Keep Stuff Out” model and its been really effective in doing just that. I’ve never fussed with pebbles or dirt getting inside the shoe.
  • Insole is of 2 mm EVA material, provides an added layer of comfort, but doesn’t distort ground-feel clarity
  • Hook-loop closure keeps the shoe locked on to the foot, so  your feet won’t slip around inside the shoe
  • Highly durable. Shoe will hold up for years
  • Machine washable. Let it air dry. Dries pretty quick.
Vibram Five Fingers KSO Review for Forefoot Running
The Vibram KSO’s individual toe sockets are flexible, allowing more optimal toe-splay as compared to the traditional running shoe. What’s the advantage of toe-splay during running? It helps supply better dynamic stability of the foot/ankle complex which can perfectly match the demands of running on uneven terrain.

The Vibram KSO can be used for:

  • Running (5km – marathon) on smooth roads, semi-technical terrain and grass
  • Walking and hiking on rugged terrain
  • Cross-Fit
  • High intensity training
  • Kickboxing; karate
  • Casual wear
  • Obstacle course races
  • Golfing
  • Soccer
Vibram Five Fingers KSO Review for Forefoot Running
I prefer wearing the Vibram KSOs for warmer temperatures, but when paired with toe socks, the KSOs are exceptional for cooler weather AND feel more comfortable!

As for sizing, because the Vibram KSO’s fit like a glove, it would be wise to get the next size up from your regular size.

Because of the influx of sensory input, you can certainly rely on the Vibram Five Fingers KSO to be largely effective at helping you not only in improving, but sustaining your forefoot strike when you run, which ultimately helps reduce cumulative strain on the knee. Even more important, when you’re in the Vibram KSO, you get stronger sensory broadband as compared to the traditional running shoe whereby most of the functional strength development in the foots musculature is tied to this sensory input! This is how the Vibram KSO plays its part in engaging the feet on many fronts to levels not experienced in the traditional running shoe.

Where to get the Vibram KSO:




Kelly’s Running Warehouse:

Road Runner Sports:

Here is an even more in-depth review I did on the Vibram KSO:

If you like these shoes, you’ll love my other reviews on barefoot-simulated minimalist shoes for forefoot running.

More From Run Forefoot:

Jogging for Starters

Is Heel Strike Bad?

How Should Feet Land When Running

Why Run Barefoot


Bretta Riches

Bretta Riches

"I believe the forefoot strike is the engine of endurance running..."

BSc Neurobiology; MSc Biomechanics candidate, ultra minimalist runner & founder of RunForefoot. I was a heel striker, always injured. I was inspired by the great Tirunesh Dibaba to try forefoot running. Now, I'm injury free. This is why I launched Run Forefoot, to advocate the health & performance benefits of forefoot running and to raise awareness on the dangers of heel striking, because the world needs to know.
Bretta Riches

P.S. Don't forget to check out the Run Forefoot Facebook Page, it's a terrific place to ask questions about forefoot running, barefoot running and injury. I'm always happy to help!

1 Comment

  1. Very interesting. First time I’ve heard of this and I thank you. I’d like to learn more. I’ve only been running for 5 years, my feet and especially my heels hurt very often. Also, I experience hip soreness on longer runs. Actually just finished my first marathon and am hoping to better my running technique. Thank you

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