The Health Benefits of Outdoor Activity

By Mike Johnson M.D.

The benefits of outdoor exercise are elaborated by many sources1-5

It leads to better health and improved quality of life. 

Outdoor exercise specifically decreases the incidence of heart disease, stroke, high blood pressure, type 2 diabetes, and osteoporosis. 2,3

Outdoor activity decreases symptoms of depression.5

And it increases confidence.  And it’s fun. 

The outdoor environment is not always conducive to mobility aids. 

So you can tailor activities to a reduced mobility requirement (e.g., yoga, picnics, gardening, outdoor concerts, yard games).1 

“Find the right mobility aid.  If you normally use a cane, but know that you’ll be spending more time walking around outside than normal, bring along another mobility aid like a walker for backup”1


This is good advice, but do you really want to limit activity and use a conventional walker?  Remember those creaky things with tiny wheels?  Even worse are the wheel locks that require indoor floors to lock.

Dumbing Down Outdoor Activities, or Not………..

But what about real activities like hunting, fishing, birding, dog walking, and exploring?


Those with an active life finding themselves with decreased mobility due to aging or disease are counseled to maintain as much of the activity they previously pursued. 


Here is where the Outdoor Activity Extender plays a role.  The cantered, wide wheels of the Walk’n’Chair were designed for outdoor surfaces.  The Walk’n’Chair morphs to be a chair to rest on, a walker with big wheels, and in a pinch will function as a typical wheelchair.  The basket will hold your binoculars, water bottle, sunscreen, and extra jacket.


While the Walk’n’Chair is cleared by the FDA as a wheelchair (k935211), it does much more.  In fact, it is an anti-wheelchair.  That’s why we call it an Outdoor Activity Extender.  It is our mission to keep people with mobility impairments such as Parkinson’s disease, disuse atrophy, mild stroke, neuropathy, and generalized weakness away from a sedentary reliance on a wheel chair.


The Walk’n’Chair is manufactured in Montana (and British Columbia), places where people treasure the outdoors.  And yes we have hunters using the Walk’n’Chair to get in a few extra seasons.  And fishing fanatics get priceless extra fish.  And the old hound gets extra walks! 


Some of our customers use the Walk’n’Chair to go down to their boat dock, haul hay for their horses, and propel their one-man band.  These users will be featured in detail in further issues of this blog.

Many people with compromised mobility still fondly remember hunting, fishing, birding, and hiking!

The Walk’n’Chair morphs to your outdoor needs.  It is


  • A Rough Terrain WalkerA Smooth Terrain Walker
  • A Rough Terrain Wheelchair
  • A Smooth Terrain Wheelchair
  • A carrier of all things fishing, hunting, and hiking.
  • A resting place in the woods
  • A stabilizing platform for binoculars and cameras.




Even Doctors are Prescribing Outdoor activity


The UKs National Health Service has authorized doctors to prescribe time outdoors. 


The web page Children and Nature references 700 articles on the positive mental and physical health aspects of outdoor exercise.5


Sometimes the physicians are the last to know……


  1. 5 Outdoor Activities for Seniors with Mobility Problems, outdoor summer fun like never before.-outdoor-summer-activities-for-seniors-with-mobility-problems/
  2. Activities for Wheelchair Bound Individuals,


  1. Exercise and Physical Activity


  1. Natural Medicine: More Doctors Prescribing Time Outdoors, Olivia Rosane, Oct 22, 2018.


  1. Web page Children and

Outside Exercise

-> Download Outside Exercise PDF

Check out the Walk’n’Chair at www.


Or email us:  USA  



Or call us:      USA            1(406) 925 5663

                         Canada          250   324 1285

The Engineering of the Walk’n’Chair


By Mike Johnson M.D.

Why does the Walk’n’Chair morph into so many configurations?

  • Because people have different mobility limitations.
  • Because people have different environments to contend with.


Outdoor  and indoor environments require an adaptive mobility device.

And some serious engineering. 


The outdoor environment is not always conducive to mobility aids. 

As the outdoor terrain becomes more irregular, it is second nature to take more care and go slowly.

Theoretically, increasing the rolling resistance of the wheels and increasing the turning radius as terrain gets more irregular mimics what people do when the going gets rough.  They slow down and take wider turns.


Rolling Resistance

Rolling resistance is related to the tire material, wheel radius and load on the wheel base (Lin et al., 2015; Mediola et al., 2014; Sprigle and Huang 2015).  Most of the resistance to rolling is due to “tire scrub” and “caster shimmy” not bearing resistance2

How Walk’n’Chair changes Rolling Resistance

Changing the configuration of the Walk’n’Chair alters the weight distribution of the load relative to the front and back wheels.  The large wheels have much less rolling friction than to the smaller caster wheels (due to size, materials, caster shimmy).

When we change the Walk’n’Chair from a Smooth Terrain Walker to a Rough Terrain Walker, the center of gravity moves from the large wheels (low  resistance) to the casters (high resistance)


This increases the rolling resistance to match the caution one normally uses in rough terrain.  Increased resistance for rough terrain gives the Walk’n’Chair a solid feel.


Turning Radius (Maneuverability)

The Walk’n’Chair turning radius is increased for the

Rough Terrain Walker configuration.  This in combination with increased rolling resistance makes the Rough Terrain Walker configuration a sturdy match for irregular terrain.

Effects of Wheel Camber

The inclination of the large rear wheels (camber) is usually reserved for athletics and wheelchair sports (Tsai et al., 2012).  Camber increases lateral stability; the effects are significant from 0-15o.  Camber allows increased turning velocities.  Camber from 8 to 15o increases

rolling resistance (Tsai et al., 2012).  A camber of 6o was found to be optimal in terms of lateral stability on smooth terrain (Mediola et al., 2014).


The Walk’n’Chair large wheel camber is 12o.  This enhances stability especially when moving over lateral slopes.

Obstacle Traverse

The largest obstacle height safely traversed is related to the wheel radius.  A curb half of the radius of the forward wheel is easily and safely crossed.


The Rough Terrain Walker and Rough Terrain Wheelchair configurations allow the traverse of rough terrain and curbs.



Several principles of wheel chair design were extracted from recent engineering literature1-8.  These principles were applied to the Walk’n’Chair.


The Walk’n’Chair modifies the center of gravity to match rolling resistance to the terrrain.  Turning radius is modified to optimize for smooth indoor or rough outdoor terrain.  Stability is increased by reducing turning radius and adding camber to the rear wheels.  Rough terrain features are traversed with larger wheels.


  1. Caspall JJ, Selgsohn E, Dao PV, Springle S (2013) Changes in inertia and effect on turning effort across different wheelchair configurations. J Rehabil Res Dev 50(10):1353-62.


  1. Lin JT, Huang M, Springle S (2015) Evaluation of wheelchair resistive forces during straight and turning trajectories across different wheelchair configurations using free-wheeling coast-down test. J Rehab Research Devel 52 (7): 763-774.


  1. Mediola FO, Elui VMC, Santana CDS, Fortulan CA (2014) Aspects of manual wheelchair configuration affecting mobility: A review.  J Phys Ther Sci 26:313-318.


  1. Sauret C, Bascou J, de Saint Rémy N, Pillet H, Vaslin P, Lavaste F. (2012) Assessment of field rolling resistance of manual wheelchairs. J Rehabil Res Dev. 2012;49(1):63-74.


  1. Springle S, Huang M (2015) Impact of mass and weight distribution on manual wheelchair propulsion torque. Assist Technol 27(4) 226-235.


  1. Thomas L, Borisoff J, Sparrey CJ (2017) Quantifying the effects of on-the-fly changes of seating configuration on the stability of a manual wheelchair. Conf Proc IEEE Eng Biol Soc 2017: 1897-1900.


7. Tsai CY, Lin CJ, Huang YC, Lin PC, Su FC (2012) The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion.

The effects of rear-wheel camber on the kinematics of upper extremity during wheelchair propulsion. Biomed Eng Online. 2012 Nov 22;11:87. 


8. Zepeda R, Chan F, Sawatzky B (2017) The effect of caster wheel diameter and mass distribution on drag forces in manual wheelchairs. J Rehabil Res Dev 53(6) 893-900

->Download Engineering of the Walk ‘n’ Chair PDF


Check out the Walk’n’Chair at www.


Or email us:  USA  



Or call us:      USA            1(406) 925 5663

                         Canada          250   324 1285