Is walking good for ligament healing?

Walking writes the grain: how a healing scar decides the orientation of its fibrils, and what immobilised and mobilised ligaments look like on the rig

Is walking good for ligament healing is a question that the honest page answers with the one thing walking does to a healing ligament that neither rest nor any supplement can do, because once that thing is understood the answer and its conditions follow from it: walking writes the grain. A ligament is a cable of collagen fibrils running in parallel from one bone to another, and its strength and stiffness come from that parallel arrangement, every fibril pulling in the same direction when the joint is stressed. When the ligament tears and fibroblasts arrive over the proliferative weeks to bridge the gap, they lay down new collagen fibrils, and a fibroblast does not know which way the ligament runs; it lays its fibrils in whatever orientation it finds itself in, and the orientation it finds itself in is set by the strain the forming tissue is experiencing. A fibroblast in a scar that is being gently stretched along one line elongates along that line and lays its collagen along it, so that the fibrils forming around it run parallel to the strain, and a fibroblast in a scar that experiences no strain at all sits rounded and lays its collagen in every direction. That is the grain, and it is written during the weeks the scar forms and refined during the months it remodels. A scar that heals in an immobilised joint, in a cast or a rigid brace or on weeks of complete rest, experiences no strain while it forms, and on the testing rig and under the microscope it is a random felt: small-diameter fibrils in every orientation, a high proportion of type 3 collagen, poor cross-linking, adhesions to the tissue around it because the scar has grown into whatever it touched, and a failure load well below a mobilised scar's; the joint it sits in is stiff, because the capsule and the surrounding tissue have stiffened with it, and the ligament-to-bone insertion has weakened because the bone beneath an unloaded attachment thins. A scar that is cyclically loaded along the line the ligament pulls in, gently, repeatedly and within what it can bear, from the first days, aligns its fibrils along that line as they form, grows them larger in diameter as it remodels, cross-links them in an organised way, and stays free of its surroundings because the movement prevents adhesions; on the rig it is stronger and stiffer than the immobilised scar at every time point, and the joint it sits in moves. The animal mobilisation studies established this by healing the same ligament in immobilised and mobilised joints and comparing them, and the human evidence confirmed it where it could, in the ankle sprain trials that compared a cast with a functional brace and early weight-bearing and found the brace better for function, for return to activity and for re-sprain rates, which is the grain being written in a clinic; the asymmetry by which unloaded ligaments lose strength fast and regain it slowly is on the ligaments get stronger page. Walking is exactly the load that writes the grain. Each step puts a cyclic, low, repeated strain through the ligaments of the ankle and knee along the lines they pull in, at a fraction of the force that tore them, and a reader who walks through the day in a brace delivers thousands of gentle loading cycles to the healing scar, orienting its fibrils without threatening its bridge, which no exercise done for ten minutes in a clinic can match for repetition and no period of rest can match at all.

The three conditions, what walking does not supply, the ligaments for which it aligns nothing, and the adjunct beside the loading

Walking is good for a healing ligament under three conditions, and the honest page gives each with its reason, because the grain is written only by a load the scar can bear. The first condition is that the joint can bear weight, and it is decided in the first days by the Ottawa rules: a reader who cannot take four steps on the injured ankle or knee, or who is tender over the bony landmarks the rules name, needs an X-ray before a walk, because a fracture masquerading as a sprain is loaded differently and the rules catch almost all of them; a reader who can take four steps and is not tender over bone has no fracture to worry about and can begin, which is the sorting by grade and by rules on the walking on torn ligaments page. The second condition is that the walk is within pain and inside protection where protection is needed. Within pain means a walk that the joint tolerates, with pain that does not climb through the walk and has settled by the next morning, and a walk that hurts with every step is a load above today's capacity, to be shortened or taken with more support rather than pushed through. Inside protection means a functional brace or taping for the ligaments that need to be guarded in a particular direction while the grain is written: the ankle's lateral ligaments, which a brace stops from being rolled again while every step still loads them along their line; the knee's medial collateral, which a hinged brace stops from being opened sideways while the knee still bends and bears weight through it; the thumb's and fingers' ligaments, which buddy taping or a splint protects while the hand is used. The brace is the thing that makes early walking safe, since it allows the strain that writes the grain and blocks the strain that would re-tear the bridge, and it is worn as prescribed and taken off when the stress test says the bridge takes tension. The third condition is that walking is not the whole programme. It writes the grain and keeps the joint moving, and it does not build the strength that the later phases need or restore the balance that the last sign depends on: the muscles around the joint weaken from the first week of injury and are rebuilt with resistance work, and the mechanoreceptors torn with the ligament are retrained with single-leg standing, unstable surfaces and hops, none of which a walk on the flat supplies, so that a reader who only walks ends with a well-aligned scar in a weak, unsteady joint, and the strength and balance work is added beside the walking from the second or third week. For the ligaments whose ends sit apart, walking aligns nothing, because there is no scar bridging the gap to align: an anterior cruciate retracted into synovial fluid, a thumb ligament folded over a tendon sheet, a lateral collateral torn with the posterolateral corner have no bridge for walking to write a grain into, and a reader with one of those walks on a joint that gives way and widens nothing but the problem, so for them the question of walking is a surgeon's first and a physiotherapist's after. The tendon version of the same question, in which walking is a dose on a load ladder rather than a grain-writer, is on the walking and tendonitis page, and the difference between the two pages is the difference between a tissue that remodels under load and a scar that forms under it. Collagen's one ligament trial, 5g a day for six months in athletes with chronic ankle instability, improved a stability score and cut recurrent sprains in lax ligaments long healed, and said nothing about the grain of a forming scar, so the adjunct sits beside the loading that writes it at the trial's powder dose, if anywhere. The worked example is that adjunct at habit scale, stated on its true terms: two capsules, 1200mg hydrolysed type 1 marine collagen with 12mg vitamin C at 15% of its reference value plus zinc, 120 for £16.99 at 28p a day, lab tested and UK made, below the 5g trial dose, carrying vitamin C's collagen formation sentence for cartilage and bones and no ligament claim. Is walking good for ligament healing: yes, because it writes the grain of the scar, under the three conditions, and beside the strength and balance work that walking cannot do.

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