The evidence points in a positive direction for stretching and targeted strengthening exercises when it comes to joint suppleness and injury prevention, but the strength of that evidence varies considerably depending on the approach. The best support applies to shoulder strengthening exercises in handball athletes; static stretching works for hip mobility just as well as more advanced methods. Tissue flossing and core muscle training are promising but have so far only been studied in small trials involving specific athletic populations.
Keeping joints supple starts with movement and stretching, but not every method is equally well supported by evidence. Both ordinary static stretching (holding a stretch for a few seconds) and PNF stretching (in which you actively contract the muscle while stretching) demonstrably improve hip range of motion. However, research has not found the two methods to differ meaningfully in effect, so for most people simple static stretching is sufficient.
A relatively new technique, tissue flossing, shows promising short-term results in small studies. It involves wrapping a tight elastic band around a joint and then moving that joint. In healthy young men, this improved the mobility of the knee extensors and hamstrings more than dynamic stretching did. In female sports students, knee flossing also improved hamstring flexibility and landing stability for at least 20 minutes. Because the effects have been measured in small groups of healthy athletes and last only briefly, it remains unknown whether this also provides protection in the long term or whether it works for broader population groups.
For protecting the knee joint specifically, there are indications that training the core muscles (trunk and hips) is beneficial for the load placed on the knee. In a small study of female basketball players (9 participants in the training group), eight weeks of core muscle training led to a significant reduction in the valgus collapse force on the knee during jumping and squatting. This suggests that a strong core contributes to better leg alignment and thereby potentially less wear on the knee joint, but the study was too small to draw firm conclusions.
Those who want to protect a shoulder joint have the strongest evidence on their side. A randomised study of 660 elite handball players showed that a programme of rotation and shoulder-blade strengthening exercises, performed three times per week, reduced the risk of shoulder problems by 28 percent (17% versus 23% in the control group). This is the most robust finding in this overview: a large study, a clear effect, and a concrete approach.
There is debate in the scientific literature specifically about stretching for runners. The available research is limited and contradictory: it has not been demonstrated that stretching prevents injuries or improves performance in runners. Runners who want to stay injury-free can combine stretching with strength training and attention to running technique, but should not expect stretching alone to have a proven protective effect.
Based on: one meta-analysis on stretching and hip mobility (PMID 28182516), two small experimental studies on tissue flossing (PMID 33239941, 35162447), one small RCT on core muscle training in basketball players (PMID 31386583), one large RCT on a shoulder injury-prevention programme in handball players (PMID 27313171), and one narrative review on stretching in runners (PMID 20610027). The total number of participants is partly unknown; the largest study included 660 participants.