Influence of Altered Knee Angle on Electromyographic Activity of Hamstring Muscles Between Nordic Hamstring Exercise and Nordic Hamstring Exercise with Incline Slope Lower Leg Board.
Taspol Keerasomboon, Toshiaki Soga, Norikazu Hirose
PMID 35949369WHAT IT FOUND
Holding the Nordic hamstring exercise at a shorter muscle length (77% of lower leg) produced higher hamstring activation than the incline board version.
Longer lengths reduced muscle activity, likely because passive tissue took over the load.
Key findings
01Biceps femoris long head activity was significantly higher during the standard Nordic exercise at 77% of lower leg length compared to the incline board version at the same moment arm.
02Semitendinosus activity was significantly higher during the incline board version at 77% of lower leg length compared to the standard Nordic exercise.
03Overall hamstring electromyographic activity decreased when the muscles were lengthened during the exercise.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
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What it does not show
The study involved only 16 male volunteers, which limits the generalizability to female athletes or broader populations. The difference in physical holding positions between the 77% and 94% conditions was small, which may have confounded the comparison of muscle lengths. The study examined isometric holds, whereas the Nordic exercise is often performed eccentrically in clinical practice. The authors suggest that the examiner's hand placement at 77% might have compressed the gastrocnemius, potentially altering hamstring activation patterns.
Declared interests
The authors declare no conflicts of interest.
The easy way to misread this
Do not assume that the incline board version is inferior for all hamstrings. While the standard Nordic at 77% activated the biceps femoris more, the incline board at 77% actually produced higher semitendinosus activation. Choosing one version over the other depends on which specific hamstring muscle is the target.