PT  - JOURNAL ARTICLE
AU  - Mette Kreutzfeldt Zebis
AU  - Jørgen Skotte
AU  - Christoffer H Andersen
AU  - Peter Mortensen
AU  - Højland H Petersen
AU  - Tine C Viskær
AU  - Tanja L Jensen
AU  - Jesper Bencke
AU  - Lars L Andersen
TI  - Kettlebell swing targets semitendinosus and supine leg curl targets biceps femoris: an EMG study with rehabilitation implications
AID  - 10.1136/bjsports-2011-090281
DP  - 2013 Dec 01
TA  - British Journal of Sports Medicine
PG  - 1192--1198
VI  - 47
IP  - 18
4099  - http://bjsm.bmj.com/content/47/18/1192.short
4100  - http://bjsm.bmj.com/content/47/18/1192.full
SO  - Br J Sports Med2013 Dec 01; 47
AB  - Background The medial hamstring muscle has the potential to prevent excessive dynamic valgus and external rotation of the knee joint during sports. Thus, specific training targeting the medial hamstring muscle seems important to avoid knee injuries. Objective The aim was to investigate the medial and lateral hamstring muscle activation balance during 14 selected therapeutic exercises. Study design The study design involved single-occasion repeated measures in a randomised manner. Sixteen female elite handball and soccer players with a mean (SD) age of 23 (3) years and no previous history of knee injury participated in the present study. Electromyographic (EMG) activity of the lateral (biceps femoris – BF) and medial (semitendinosus – ST) hamstring muscle was measured during selected strengthening and balance/coordination exercises, and normalised to EMG during isometric maximal voluntary contraction (MVC). A two-way analysis of variance was performed using the mixed procedure to determine whether differences existed in normalised EMG between exercises and muscles. Results Kettlebell swing and Romanian deadlift targeted specifically ST over BF (Δ17–22%, p<0.05) at very high levels of normalised EMG (73–115% of MVC). In contrast, the supine leg curl and hip extension specifically targeted the BF over the ST (Δ 20–23%, p<0.05) at very high levels of normalised EMG (75–87% of MVC). Conclusion Specific therapeutic exercises targeting the hamstrings can be divided into ST dominant or BF dominant hamstring exercises. Due to distinct functions of the medial and lateral hamstring muscles, this is an important knowledge in respect to prophylactic training and physical therapist practice.