Quo Vadis Nordic Hamstring Exercise-Related Research?—A Scoping Review Revealing the Need for Improved Methodology and Reporting

Abstract

The objective of this scoping review is to assess Nordic Hamstring Exercise quality (ANHEQ) of assessments and interventions according to the ANHEQ rating scales and to present practical recommendations for the expedient design and reporting of future studies. A total of 71 Nordic Hamstring Exercise (NHE) assessments and 83 NHE interventions were selected from the data sources PubMed, Scopus, and SPORTDiscus. Research studies which were presented in peer-reviewed academic journals and implemented the NHE during laboratory-based assessments or multi-week interventions met the eligibility criteria. NHE assessments analyzed force (51%), muscle activation (41%), knee angle kinematics (38%), and bilateral symmetry (37%). NHE interventions lasted 4–8 weeks (56%) and implied an exercise volume of two sessions per week (66%) with two sets per session (41%) and ≥8 repetitions per set (39%). The total ANHEQ scores of the included NHE assessments and interventions were 5.0 ± 2.0 and 2.0 ± 2.0 (median ± interquartile range), respectively. The largest deficits became apparent for consequences of impaired technique (87% 0-point-scores for assessments) and kneeling height (94% 0-point-scores for interventions). The 0-point-scores were generally higher for interventions compared to assessments for rigid fixation (87% vs. 34%), knee position (83% vs. 48%), kneeling height (94% vs. 63%), and separate familiarization (75% vs. 61%). The single ANHEQ criteria, which received the highest score most frequently, were rigid fixation (66% of assessments) and compliance (33% of interventions). The quality of NHE assessments and interventions was generally ‘below average’ or rather ‘poor’. Both NHE assessments and interventions suffered from imprecise reporting or lacking information regarding NHE execution modalities and subsequent analyses. Based on the findings, this scoping review aggregates practical guidelines how to improve the design and reporting of future NHE-related research.

Nordic hamstring exercises in functional knee rehabilitation after anterior cruciate ligament reconstruction: a prospective, randomised, controlled study

“…The results in Table 1 show that when comparing the difference in thigh circumference between the two groups of patients preoperatively and 12 weeks postoperatively, the difference in the control group was lower than that in the experimental group, suggesting that Nordic popliteal exercises were able to reduce the difference in thigh circumference in the patients.Using the circumference to evaluate the swelling, considering that in the preoperative period the influence on the circumference of the lower limb is mainly soft tissue oedema, and in the postoperative period of 12 weeks, it may be accompanied by the change of muscle atrophy, and the influencing factor on the circumference may be mainly a muscle problem 32 , so the observation period was set as 12 weeks and 24 weeks.The reason for this is that in the training mode of Nordic hamstring exercise, patients choose flexible resistance according to their own situation, which can activate the knee blood vessels and promote the flow of blood vessels in the joints of patients, thus reducing the swelling of the knee joints and reducing the difference in the circumference of the thighs of the patients, so as to keep them in line with the healthy side of the leg 33 . The results of this study showed that after treatment, the flexor-extensor PT, TW value, and AVG PT of patients in the observation group were higher than those of patients in the control group, suggesting that patients with Nordic hamstring exercises can achieve a loading pattern that matches their actual situation, which can maximise the restoration of their own leg muscle tone, and thus restore their muscle strength 34 .…”

Kräftig und beweglich zugleich – Zielgerichtetes Training der Ischiokruralmuskulatur

“…3 Sätze à 3 Wdh.) 5 , 7 . Die dadurch bedingte geringe muskuläre Ermüdung und die zumeist kontrolliert langsame Bewegungsgeschwindigkeit bewirken eine hohe Kontraktionskraft der Muskeln und erhöhen die tendinöse Komponente der Bewegung, was die Bewegungseffizienz verbessert.…”