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Tendency to cramp in the rectus femoris

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last update: 30.5.2003
Name: Spasms in the rectus femoris

• Classification
• Contraindication
• Effects
• Preparation
• Follow-up
• derived asanas
• similar asanas
• Diagnostics
• Instructions
• details
• Variants

Instructions

1. Perform dandasana and straighten the pelvis as much as possible.
2. Raise the right leg as far as possible and observe whether a cramp develops in the rectus femoris. If this occurs, lower the leg again.

details

1. The dandasana is noticeably more suitable for this experiment than the eka pada prasarita tadasana, for example, because in the tadasana, as a neutral-zero-like pose, ideally no force needs to be exerted to keep the pelvis in a vertical position. This would at least be the physiological state. In practice, however, there are often shortened hip flexors, which is why the pelvis must be held upright with the strength of the hip extensors. In this case, it is not necessary to use the hip flexors at all to keep the pelvis upright. The ipsilateral hip flexors and therefore the rectus femoris are only used to lift one leg. In dandasana, however, it is necessary for many people – depending on the degree of flexibility or shortening of the ischiocrural group – to use the hip flexors to straighten the pelvis anyway, so that an additional demand on the rectus femoris, such as that created by lifting the leg, can quickly lead to a high load, which also increases disproportionately with every degree of flexionangle in the hip joint, because the resistance of the ischiocrural group quickly exceeds any manageable level. As the knee joint is extended in this posture, the biarticular rectus femoris is at a very short, almost minimal sarcomere length, so that a cramp is only likely, depending on the force applied. This posture therefore provides a good opportunity to observe and explain this muscle behaviour.
2. Very flexible people naturally do not need to use the hip flexors in dandasana to straighten the pelvis, which is why the phenomenon is not necessarily better observed in them than in eka pada prasarita tadasana.