When feeling the first discomfort in their knees when walking or climbing stairs, most people’s immediate instinct is to suspend any type of physical activity, believing that absolute rest will protect the leg against further damage. For medicine, however, this decision of immobility is the starting point for the accelerated destruction of the body’s structure: the knee is a gear designed exclusively for movement, based on physical exercise.
To demystify the factors that really condemn the health of the joint and understand the mechanics of protecting our body, the report heard Pedro Ribeiro, an orthopedic doctor specializing in knees and regenerative medicine at the Orion clinic. The specialist’s diagnosis subverts common sense: early wear and tear is not the fault of the impact itself, but of the weakening of those who are receiving that impact.
“I often say that being overweight are the main habits that harm our knees on a daily basis,” he says. He details that many patients avoid exercise out of fear, ignoring that physical activity is the only stimulus capable of creating a protective barrier.
“Sometimes people think about not practicing any type of sport or exercise because there is a greater risk of damage to the knee. However, sport always encourages us to maintain weight and strengthen muscles”, warns the doctor. When a person loses lean mass and gains weight, each step taken transfers a crushing load straight to the bones, with no active buffer to dissipate the energy.
The muscular “padlock” and the preservation of cartilage
The body’s anatomy is made up of a complex network of ligaments, but the central structure that guarantees fluidity in the stride and prevents the bones from “scraping” against each other is cartilage. Unlike other tissues in the human body, it has almost zero capacity for regeneration. “Cartilage is our greatest rarity and precious item within the knee. So, everything we do around it aims precisely to protect this cartilage”, he explains.
The biological strategy to shield this area is to build a barrier around the bones. “The muscular envelope, as I like to call it, is one of the main factors responsible for joint stability. And this stability is one of the main factors responsible for less cartilage wear”, explains the specialist. “A voluminous and strong thigh is not an aesthetic standard, but a physical shield.”
In order for the body to support the weight of a run or a simple squat without crushing the center of the knee, it depends on the (the front of the thigh), the internal muscles that stabilize the patella (the vastus medialis oblique), the muscles on the back of the leg and the calves.
The doctor illustrates the union of these forces as a closed security system: “I often say that this is like a padlock. We have to strengthen the thigh very well, both anteriorly and posteriorly, and the calf so that this knee can have greater stability.”
Excess load and the use of specific shoes
If inactivity destroys the knee due to weakness, sports performed without guidance harm it due to uncontrolled excessive load. Physical training needs to be dosed, as overdoing it crushes the joint tissues before they have time to recover from the previous effort.
“Excessive exercise can also overload the knee. So it is obvious that the training has to be prescribed by a professional in the field, by someone who is qualified, and carried out correctly so that there is no damage.”
The impact of repetitive stepping on the asphalt or treadmill is also shaped by the base of support the practitioner chooses to use. The initial force absorption falls directly on the feet and immediately rises to the knees.
Wearing incorrect shoes forces the foot to crooked and throws all the impact to the sides of the leg. “Today we have specific footwear for each sport. The use of , especially in impact activities, as well as strict attention to posture”, highlights the specialist.
The weight of muscle shortening in locomotion
In sports that require contact and sudden changes of direction, such as football, the demand on the body reaches its maximum level. Football leads the rates of orthopedic surgeries in the country due to quick stops and high-speed turns. “These sports require better muscular maturity, because there is a very fast rotation”, he points out. Without strong muscles to “brake” the body, the force of the turn bursts the internal ligaments in a fraction of a second.
Another chronic failure, both in high-impact sports and bodybuilding, is the abandonment of flexibility. Short, rigid and inelastic muscles pull the knee away from its original axis. “They are very important, because shortening causes difficulties and differences in the way of locomotion and range of movement”, explains the orthopedist. The guideline is that the physical routine should never be focused solely on lifting weights. “It is essential to set aside time before the main activity to focus on stretching and strengthening, a preventative practice that has become increasingly prominent”, he adds.
The identification that the knee structure has collapsed occurs through two exact clinical categories of pain. Acute injuries occur immediately after direct trauma or sudden sprains, generating rapid swelling and so-called joint blockage, a physical lock that prevents the patient from fully stretching or bending the leg.
On the other hand, chronic accumulation injuries present persistent inflammatory conditions, clinically documented as patellar tendinitis, quadriceps tendon tendinitis and pes anserinus tendonitis. In these scenarios of continuous wear and tear, the pain becomes prolonged and progressive, gradually worsening with each new repetitive physical effort, and is often accompanied by episodes of joint instability, in which the leg presents visible distortions during walking.
