How is the foot supposed to land during running?

Feedforward activity of the transversus abdominis and multifidus muscle in a forefoot versus rearfoot strike running pattern, a pilot study.  JSvD 2008

The aim of this study was to assess differences in muscle activity of the abdominus transversus muscle and multifidus during running in two different kinds of a running pattern - the rear foot strike running pattern and the forefoot strike running pattern.
This study has demonstrated clearly that the activity of the abdominus transversus is more symmetric in the RFS (rear foot strike) running pattern than it is in a FFS (forefoot strike)running pattern. The results indicate that superior core stability is achieved in a RFS running pattern.
The advantages of a RFS are:
- A slightly diminished impact peak at midstance compared with a FFS running pattern. This might be essential because the greatest potential for injuries during running is also at 60 % of the stance phase. In this mid to late stance maximal calcaneal loading occurs together with maximal Achilles tendon, plantar ligament and plantar fascia tension.
- The mean center of pressure pattern in a RFS running pattern is moving in an almost rectilinear motion toward the midline and the anterior part of the foot. The mean center of pressure distribution in a FFS running pattern however does not demonstrate this rectilinear motion. The first contact is made at approximately 50% of the foot length. After this first contact, the center of pressure is making a brief anterior movement, then changes its direction in a posteriorly / medially direction before moving anterior again. It seems reasonable to hypothesize that FFS runners are particularly at risk since they are experiencing large forces in a region not “designed” for these impact forces.
- Ardigo (7) found that the mechanical work (in watt/kg) was significantly higher (7-8%) for a FFS compared with a RFS for a running speed between 2.5 and 4.0 m/sec. The oxygen uptake however was similar for both groups, meaning that a higher storage and release of energy take place in the elastic structures of the lower leg with a FFS. The RFS running pattern at the same speed might be more gentle for the anatomic structures in both feet and lower extremities.
- A more symmetrical contraction of the transversus abdominus muscle means a better core stability for the RFS running pattern.
Relevance of core stability
A strong foundation of muscular balance and core stability might be essential for distance running. Weakness or lack of sufficient coordination in core musculature could lead to less efficient movement, compensatory movement pattern, strain and overuse injuries.

Zusammenfassung

Aus verschiedenen Gründen läuft eine beträchtliche Anzahl von Läufern bei geringer und moderater Geschwindigkeit mit einem Vorfußkontaktlaufmuster, obwohl die menschliche Ferse beim Walken und langsamen Laufen anatomisch für die Fersenlandung „designt” zu sein scheint.
Die vorliegende Ex-post-facto-Forschungsarbeit untersuchte die bilaterale Aktivität von M. transversus abdominis und M. multifidus, um Hinweise auf die Rumpfstabilität beim Rückfuß- versus Vorfußkontaktlaufmuster zu finden.
Bei 12 weiblichen Freizeitläufern (je 6 Vorfuß- und Rückfußkontaktläufer) mit gleichem Gewicht, Größe, Alter und Lauferfahrung wurden während Laufbandjoggen mit definierten Geschwindigkeiten bilaterale oberflächliche EMG-Daten des M. transversus abdominis und M. multifidus gesammelt. Außerdem wurden die IEMG-Werte zwischen Muskeleinsatz und initialem Kontakt (Feedforward) quantifiziert. Das Rechts-/Links-Verhältnis dieser Werte wurde berechnet und analysiert.
Laut der aktuellen Literatur wird empfohlen, bei geringen und moderaten Geschwindigkeiten mit einem Rückfußkontaktmuster zu laufen. Die in der vorliegenden Studie festgestellte symmetrischere Aktivierung des M. transversus abdominis könnte auf eine bessere Rumpfstabilität beim Rückfußkontaktlaufmuster bei den untersuchten Geschwindigkeiten hindeuten.