The relationship between low step rate and the risk of running injury seems quite logical and obvious.
To maintain a given speed, we can make frequent and short steps, or increase the length of the step with the inevitable reduction of the cadence. In this case the phase of flight increases significantly. The contact with the surface in this case must absorb more energy transmitted through the shoes, bones, joints and ligaments.
All this should be more traumatic and contribute to some types of injuries. But such a correlation is not detectable.
Some studies (e.g., the Massachusetts study) found slightly higher average step rates for ever-injured amateur runners than for those who ran without injury (164 versus 160 steps per minute, on average, at the same speed). The group of subjects was small, so these numbers are very tentative and can easily be swapped out.
In other similar studies and in those where data on frequency and stride length during running are also considered, similarly no correlation with injury risk was seen.
Landing during running has such an important indicator as the peak load that occurs when the foot makes contact with the surface. In the same study, it was observed that the peak impact load in injured runners was almost 30% higher than in uninjured runners, even despite their short stride and high cadence.
As you can understand, increasing the length of steps while decreasing their frequency has no effect on the risk of injury. Much more important is the landing technique to minimize peak loads.
Among amateurs who have suffered running injuries, such flip-flops, hard heel landings, and toe sticking when trying to change the landing technique to a more correct one are conspicuous.
Together with seaming and turning the foot outward or inward, these errors cause overstretching of the Achilles, tendons, splints and knee problems.
A slightly longer stride, caused by increasing the angle of the hip extension (rather than the heel extension), can contribute to a proper and soft foot placement, dramatically reducing the peak load on landing. Even though more energy needs to be extinguished.
However, this can be counterbalanced by putting the shin forward and then landing on the heel far in front of the center of body mass. In this case, the impact load, on the contrary, increases to critical moments.
Vertical oscillations play no small role in running technique and energy expenditure, so they should be optimized. But the assumption that they should be close to zero is wrong.
A cadence of 180 steps per minute is considered close to ideal. This is the average cadence at which most world-class pros run, and it is considered optimal in terms of the ratio of productivity and biomechanics, as well as physiology. But it is a competitive level. On standard training, the average cadence of amateurs is 160-165 steps.
The high stride frequency in elite running correlates with a large hip angle and a wide stride. This is why the marathon distance is covered in just over 2 hours.