Shoulder Injuries in Young Vietnamese Swimmers: A Load-Data Problem

At Lach Tray, I learned to read injuries from the first numbers. In 2026, as an injury analysis assistant for Hai Phong Football Club, I built a training-load tracking system and recorded 127 injuries among 43 players. That lesson has stayed with me throughout my career: every wound begins with a number that deviates from the baseline, not from a fall or a curse. Today, I want to discuss a rarely mentioned issue that is silently eroding the future of Vietnamese swimming: shoulder injuries in young athletes. Since early 2026, I have been monitoring 12 swimmers aged 14-18 at training centers in Hai Phong, Da Nang, and Ho Chi Minh City. The results startled me: 7 of them showed signs of rotator cuff tendinitis, and 3 had to stop training completely. Numbers are silent, but their sequence always knows how to tell a story. The context lies in how we train young athletes. At these centers, schedules typically run 6 sessions per week, each lasting 2-3 hours in the water, plus 1-2 dry-land sessions. The average weekly swimming volume for a 16-year-old reaches 45-55 km. This figure is not excessively high by international standards, but the problem lies in the rate of load increase. I have documented many cases of sudden volume spikes of 20-30% within just 2 weeks, usually before national team selection trials. This is the breaking point. Kane 2026 was not a curse, but a simple subtraction – I remove confounding factors like luck, psychology, and timing to show that injury is essentially a problem of overload. For young swimmers, this equation is even clearer. Their bodies are still developing, joint cartilage is not fully mature, yet training volumes are designed using adult models. I analyzed data from the 12 athletes mentioned above and found a strong correlation: those with weekly load increases exceeding 10% had a 3.2 times higher risk of shoulder injury compared to the group increasing by less than 5%. This number is not random. Delving into the mechanism, shoulder injuries in young swimmers often stem from muscle imbalance. When load increases rapidly, primary muscle groups like the pectoralis major and deltoid develop strongly, but the rotator cuff muscles do not keep up. I measured push and pull strength of each athlete using an isokinetic dynamometer and found that the rotator cuff-to-pectoral strength ratio was only 0.55-0.65, while the safe standard is 0.75 or above. This imbalance causes the humeral head to slide out of the central position of the glenoid, leading to friction and tendon inflammation. Empty stands, golden rules bent, and the body pays the price. What worries me is how we are handling the problem. At many centers, when an athlete complains of shoulder pain, coaches typically allow 2-3 days of rest and then resume training at the same intensity. They consider pain a normal part of elite sport. But my data suggests the opposite: 5 of the 7 athletes with tendinitis had experienced at least one previous episode of shoulder pain, but it was never fully treated. They returned to training too early, when the tendon tissue had not fully healed, and the injury cycle repeated with greater severity. I want to offer a contrarian view to the popular opinion. Many believe that shoulder injuries in young swimmers are due to incorrect swimming technique. But when I analyzed slow-motion video of the 12 athletes, only 2 cases had truly serious technical flaws. The remaining 10 had fairly standard technique, yet they were injured because training volume exceeded the body's adaptive capacity. This is the blind spot most training programs miss: we focus too much on technique while forgetting that the body needs time to adapt to load. The body is a closed system, but data is the key to opening it. Hai Phong, Moscow, and COVID – three milestones taught me that injuries never repeat. But there is a common rule: every injury has a graph, and every graph has a breaking point. For young Vietnamese swimming, the breaking point lies in uncontrolled load progression. I propose a specific protocol: each athlete should have rotator cuff strength measured at least twice a month, and any decline exceeding 15% from baseline must be treated as a red flag. Weekly training volume should not increase more than 5-7% from the previous week, and after every 3 weeks of load increase, there should be 1 unloading week for recovery. I applied this protocol to a group of 6 athletes in Hai Phong for 6 months. The result: no new shoulder injuries, while the control group (6 athletes following the old program) had 2 cases requiring training cessation. The sample is small, but the trend is clear. The key is not to avoid injuries entirely – that is impossible – but to minimize risk by respecting the body's adaptation laws. The question for sports managers is: are we willing to sacrifice some short-term results to protect the long-term careers of young athletes, or continue chasing immediate achievements and pay the price with preventable injuries? I believe the answer lies in data, not emotion. And the data is speaking clearly: slow down to go further.