While there can be many reasons for injuries, the reasons highlighted by the author are incorrect. Here is the explanation:

The original post argues that high daily step counts (like 15,000+) hammer sagittal-plane muscles – quads, hamstrings, glutes, calves while leaving frontal-plane stabilizers (especially adductors) under-activated, leading to imbalances that cause medial knee loading, uneven cartilage wear, and eventually knee osteoarthritis (OA). It frames walking as overworking the outer/posterior chain at the expense of inner thigh stabilizers, with the fix being targeted adductor strengthening to prevent the need for knee replacements.

Except that walking doesn’t ‘overwork’ these muscles and instead underworks them in the context of recreational/everyday level walking on flat surfaces in cushioned shoes, the reality for most people hitting high step goals. In practice, the biomechanics and muscle recruitment patterns reveal under-engagement of key power muscles rather than overuse or hammering. Its completely opposite if at all…

Calves (gastrocnemius/soleus): These aren’t hammered in typical walking. True calf exhaustion requires full-range concentric plantarflexion e.g. calf raises or sprints. In recreational walking with heel strike on normal roads/parks/shoes, the push-off phase gets muted – the ankle doesn’t fully extend through its arc, shortening time under tension and reducing peak force.

Calves act more as endurance controllers – eccentric during mid-stance, than powerful propulsors. No visible built-up calves from daily steps alone proves this: they’re underworked for strength and full ROM. This under-engagement shifts propulsion demands forward to the knees, increasing shear and medial compartment stress contributing to OA NOT from overworked calves, but from their lack of proper function.

Glutes (especially gluteus maximus): As the body’s most powerful hip extensor, glute max demands significant stimulus for full-fiber recruitment (extension like stairs climbing, sprinting or heavy lifts).

In flat walking, EMG data show low-to-moderate activation for glute max and ironically the most powerful muscle is working mostly as a stabilizer during late stance. Nobody build glutes from walking alone. Inactivation is common in modern sedentary patterns + repetitive flat gait. Glute max fibers integrate tightly with the thoracolumbar fascia (TLF), connecting to erector spinae and other back muscles. When glute max doesn’t fire fully, the TLF loses smooth glide, restricting energy transfer and forcing smaller, more fatigue-prone lower back muscles (erectors, QL) to compensate. This circuitry disruption explains why many walkers – who are inactive otherwise, complain of chronic low back pain not from overactive glutes, but inactivated ones overloading the back chain. Those who walk regularly and have active lifestyles have always stayed injury free and walking is protective for them.

Adductors (inner thigh group): Contrary to being underfired or along for the ride, adductors are optimally recruited as frontal-plane stabilizers in level walking. They consistently fire to control pelvic drop, resist valgus/varus forces, and maintain knee tracking. This reliable, low-force stabilization explains why pure walkers rarely suffer groin strains or adductor injuries unlike runners or multidirectional athletes (soccer, hockey), where adductor strains are far more common. In everyday gait, adductors handle their job without exceeding capacity or causing issues. If at all, this is the only muscle group which is optimized fully in walking.

The real imbalance in high-volume flat walking isn’t stronger outers overpowering weak inners leading to varus collapse. It’s under-challenged sagittal-chain power (muted calves/glutes push-off) forcing compensations: knees take extra load (OA risk), and back muscles overwork (LBP). Weak stabilizers bilaterally play a role, but adductors aren’t the neglected weak link, the post is reversing the pattern.

Bottom line: No single exercise is enough to keep you truly healthy. Even well-trained, muscular individuals not only get injuries but also face metabolic and other health issues as they age. You need a combination of activities, it doesn’t necessarily mean heavy weightlifting. Simply getting up from a chair a few times activates the gluteus maximus more than walking for an hour. Likewise, releasing tight calf muscles followed by controlled plantarflexions can wake up inhibited calf fibers far more effectively. Combining strength training with walking provides an excellent overall workout, especially for the upper body, which benefits more from resistance work due to its higher proportion of type II (fast-twitch) fibers.

My recommendations for people who don’t wish to strength train and only do walking

  1. Release hamstrings, quads, and calves regularly. You won’t feel these muscles but also understand what happens when you start releasing regularly
  2. Do sit and stand on a chair a few times everyday or free weight squats by holding onto a pole or chair or anything. Keep your glute max activated or save it from under activation. It will keep your lower back pain free.
  3. Do something about your upper body. Do home exercises or while walking in the park. Shoulders need both movement and extensions to contract its musculature and to keep the intra muscular balance at shoulder. This will save you from any kind of neck pain or shoulder pain.
  4. Last is do some exercises for your arm. Just like calves and shoulders; triceps is a tricky muscle. It often creates imbalance in the movement circuitry leading to elbow or shoulder pain.   

Here is an article that discusses this musculature in details:

Cricket spikes & injuries! Science….