What helps build stronger joints?

The insurance policy: what the injury prevention trials tested, how much they cut knee and ankle injuries by, and what no trial has ever used

What helps build stronger joints is a question the shelf answers with a tub and the honest page answers with an insurance policy, because stronger joints means, to the person asking, joints that do not get injured in the sport they play and do not wear out in the life they lead, and there is a trial literature on exactly that outcome which the shelf never mentions, since it contains no shelf. The trials are the injury prevention trials, and the honest page describes what they did because the design is the point. A programme is written, usually fifteen to twenty minutes long, to be done before training as a warm-up, combining four things: strength exercises for the muscles that cross the knee and ankle, squats, lunges, Nordic hamstring curls, calf raises; balance exercises on one leg, on the floor and then on an unstable surface, with and without a ball; jumping and landing drills that teach the knee to land over the foot rather than collapsing inward; and running and cutting drills that teach the same alignment at speed. Whole teams are then assigned by lot to the programme or to their usual warm-up and followed through a season, with every injury recorded, and because the unit assigned is the team the trials are called cluster-randomised, and because the outcome is an injury that happened or did not, the result is as hard as a trial result gets. Those trials, in football, handball, basketball and other team sports, in men and women and in adolescents and adults, cut knee and ankle injuries by around a third to a half in the programme teams compared with the usual warm-up teams, with the largest reductions in the injuries a stronger joint is supposed to prevent, the anterior cruciate ligament tear and the ankle sprain, and with the effect depending on compliance, so that teams that did the programme twice a week or more gained most. The components have been tested apart as well as together. Strength training alone, across the prevention trials that used it, cut sports injuries by around a third and overuse injuries by nearly half in the meta-analysis of the field, a larger effect than any other single component, which is consistent with the ligament's three jobs on the collagen help ligaments page, since the muscles that cross a joint do most of the work of holding it. Proprioceptive training alone, single-leg balance progressing to unstable surfaces, cut recurrent ankle sprains in the trials that followed previously sprained players through a season, restoring the reflexes the first sprain had slowed. Stretching alone, which generations of warm-ups consisted of, did not reduce injuries in the trials that tested it. And across the whole field of injury prevention trials, in every sport and every population, no trial has ever used a dietary supplement as the intervention, which is a statement about the field and not a criticism of collagen in particular: nobody has assigned teams to collagen or to glucosamine or to anything swallowed and counted their injuries, so the shelf's offer of a stronger joint is an insurance policy that no insurer has ever tested, sold beside a policy whose claims record is published.

The levers the policy is made of, the clock each runs on, body weight for the knee, where collagen's one trial sits, and the worked example

The levers that build stronger joints are the components of the tested programme, and the honest page gives each with the job it does and the clock it runs on, because the order of return is the order a reader should start in. Muscle comes first, because muscle provides most of a joint's stability and absorbs the load of each step, landing and tackle before it reaches the ligaments and the joint surface; the quadriceps and hamstrings for the knee, the calf and the peroneals for the ankle, the rotator cuff and the scapular muscles for the shoulder, trained with resistance two or three times a week, strengthen in weeks and are the fastest and largest lever in the trials. Balance comes second, single-leg standing on the floor, then eyes closed, then on an unstable surface, then with a ball or a partner, a few minutes most days, which trains the joint position sense and the protective reflexes that catch a joint as it starts to go, adapts in weeks and is what cut recurrent sprains. Technique comes third, the landing with the knee over the foot and the hip back, the cut that keeps the knee from collapsing inward, rehearsed slowly and then at speed, which keeps the loads of sport off the ligaments that fail when the knee collapses, learned in weeks and kept for life. Progressive loading of the tendons and ligaments comes fourth, and runs underneath the other three on its own clock, since the tendons stiffen over months of heavy loading and the ligaments over months of loading through their range, on the turnover clock set out on the strengthen connective tissue page, so that a reader who trains strength, balance and technique for a season has stronger joints within weeks by the first three levers and stronger connective tissue inside them by the end of the year. Body weight is the knee's own lever, added for the reader whose stronger joints are a question about wear rather than sport: each kilogram carried adds around four across the knee with every step, so a lighter body is a knee that takes less load through every one of the million steps a year, and the osteoarthritis guidance puts it first with quadriceps strength beside it. Under all of it runs the floor, protein at the intakes a training person needs, vitamin C for the collagen enzymes, sleep for the night's repair and no smoking for the connective tissue's maintenance, each a condition and none a lever. Joint strength defined in its three parts, stability from muscle and balance, load capacity from conditioning and structural integrity, is on the stronger joints supplement page, and the programme serves all three. Where collagen's one trial sits is beside the programme and not in place of it: 5g a day for six months in athletes with chronic ankle instability cut recurrent sprains and improved a stability score against placebo, a small manufacturer-funded trial in which the athletes went on with whatever training they did, so that the result is an adjunct's result beside an untested background, and the trial measured no ligament strength, did not assign teams and did not count injuries across a season, which is the difference between a supplement trial and an insurance policy. The worked example is the 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 ankle trial dose, carrying vitamin C's collagen formation sentence for cartilage and bones and no joint claim of its own. What helps build stronger joints: the insurance policy that has been tested, strength, balance, technique and progressive loading, with body weight for the knee and the floor beneath, and the shelf's offer an untested policy sold beside it.

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