Nordic Hamstring Curls are a cornerstone exercise in athletic development programmes, especially those that prepare athletes for sprint based activity. A depth of research on this particular exercise demonstrates extremely high muscle activation across the hamstring group with reliable changes to muscle strength and fascicle length of biceps femoris long and short head muscle with repeated Nordic exposure.
Both muscle length and strength are considered primary risk factors for biceps femoris injury (hence why the nordic hamstring curl is so popular) but so often this exercise is coached with little consideration given to another major risk factor for hamstring injury: lumbar-pelvis control under high hamstring demand.
In both sprinting and Hinge exercises the demand on the hamstring group and posterior chain is high. When hamstrings are highly active (in high-speed sprinting and low-speed hamstring exercises alike), a common compensation is toward lumbar extension/anterior pelvic tilt as the body searches for mechanical advantage at longer hamstring lengths. Some anterior pelvic tilt is associated with elite level sprinting as athletes maximise on the fringes of performance, but this expert lumbo-pelvic motion must be built on more foundational trunk, hip and pelvis control which I propose can be achieved with strength training coached in a particular way.
Like many Hinge exercise, Nordics create an opportunity to practice saggital plane pelvis control under high hamstring load. To achieve this we must coach Nordics with a priority on pelvis positioning. This places equal demand on the anti-extension muscles of the anterior trunk (rectus abdominis, internal and external obliques) to resist the powerful action of the posterior chain as it searches for mechanical advantage. Over time we hope to train an effective force couple across a stable pelvis as a foundation for more complex, multi-planar sports skills.