Flying Side Kick is a fancy looking kick, which in most peoples' minds is reserved for the movies, demonstration and breaking. However from a power point of view, it combines two monsters:
- One is a the strongest muscles in the body, the compound leg extensors. Same muscles that helps one squat and dead lift heavy weights.
- That not being enough Flying Side Kick also pack the full weight of the body, being accelerated into the target.
From a practicality point of view it's not as easy to land as a Jab or Back Fist. And yet the kick had been landed in the ring and on the street. If the two steps are removed the Flying Side Kick becomes a rear leg side kick with a hop. Done properly still a very powerful kick.
So now let's take a look at the Kinesiological Analysis of the kick.
Phase One: Take Off
There are various schools of thoughts on how the chamber should be raised.
- Some styles and individual practitioners come up with vertical shin.
- Others add rotation at the take off.
We will analyze a vertical lower leg:
The chamber comes up similar to the front kick and the rest of the body resembles a basketball layup.
On the kicking leg: the hip flexors assisted by the adductors flex the hip. Hamstrings flex the knee. Tibialis Anterior dorsi flexes the foot to expose the heel as the point of impact.
In the supporting leg: the Quadriceps extends the knee, Gluteus Maximus assisted by the Hamstrings extend the hip. Gluteus Medius and Minimus stabilize the hip. Calf completes the push off.
Spinal Extensors and Quadratus Lumborum are primary core stabilizers, especially if the torso is not completely vertical prior to take off.
Even at this stage, where flexibility does not seem to be a large factor. Allowing the muscles to lengthen properly will boost the take off.
In the right leg Quadriceps Vastii (Three Short Heads of the Quadriceps) lengthen to all the knee to flex. Gluteus Maximus, Adductor Magnus Ischial Fibers and Adductor Longus stretch allows the knee to gain its maximum height. Calf, especially Soleus flexibility, permits the heel to be exposed as the point of impact.
In the left leg Hip Flexors and Adductors Lengthen to allow for full hip extension. Tibialis Anterior allow the foot to point.
Phase Two: Impact
"You watch too many movies" maybe the right phrase used here.
Not always, but rather frequently the kick extended prior to impact. This looks great as the audience get to see how a fully extended kick looks like.
However in practicality it's like extending a punch straight at the elbow and trying to push someone with it. The leg must not be straight at the point of impact.
- More biomechanics at the upcoming articles. Right now let's take a look at the muscles involved in delivering the force of the kick to the target.
At the full extension the kicking leg is medially rotated and abducted. Three muscles carry out these two actions:
- Gluteus Medius
- Gluteus Minimus
- Tensor Fascia Latae.
- Gluteus Maximus.
The Former extends the knee and later extends the hip. Tibialis Anterior makes sure the proper point of impact slams into the target.
The supporting leg is characteristically flexed at the knee, abducted and externally rotated at the hip. There many variations to this position.
- Some kickers have their legs just slightly bent during Flying Side Kick
- Others lift the heel as high as the abdomen.
A complete lateral flexion calls for contraction of all the core muscles on the right side. Right Obliques, Right Side of the Rectus Abdominis, Right Quadratus Lumborum and Spinal Extensors hip to pull the Iliac Crest and Floating Ribs together. Psoas Major and Minor also assist.
While the non-kicking leg flexibility can make a kicker look good, it's the core and kicking leg flexibility that really counts.
- In the left leg the adductors and pectineus are the primary muscles that get stretched, providing that the heel comes up to the groin or abdomen.
- The right adductors and pectineous also lengthen to allow abduction. They are not at full stretch however, due to medial rotation of the side kick.
- A lesser mentioned muscle called Quadratus Femoris, is both and adductor and an external rotator. It is completely elongated during the kick.
- Of course Calf is stretched to allow dorsi flexion.
- In the core all the muscles on the left side of the body are expanded, to allow flexion to the right.
Part Three: Recovery and Landing
If a martial artist wants to keep doing this kick, he must learn how to land. Two actions are combined here.
- Pulling the leg back from the kick
- Absorbing the force of landing.
Not everyone lands the same way.
- Some kickers land with a front kick chamber
- Others with abducted and medially rotated side kick chamber.
- Due to a frequent attempt to utilize Glutes in the kick, many kickers land sideways and even turned away from the target.
- Tensor Fascial Latae is at great mechanical advantage, when the hip if flexed and medially rotated.
- Gluteus Medius and Minimus favor the medial rotation.
- Pectineus and adductors want to help, but be completely or partially negated by abduction, if the is on the side as opposed to being in front.
- Other hip flexors favor the lateral rotation, so they will be negated with increased internal rotation of the femur.
On the landing leg, the Quadriceps and Calf will absorb the brunt of impact.
- Medial and Lateral Rotators will work to stabilize the hip.
- If the torso falls slightly forward, Gluteus Maximus and Hamstrings will fire to keep it in check. This usually happen with very internally rotated kicking leg.
On the other hand if the kicking leg recovers into front kick position, the torso may fall back slightly (shoulder behind the hips) and hip flexors combined with adductors will keep it in check.
Muscles of the core will mimic the position of the torso and fire in chain with the lower body.
- Spinal extensors and quadratus lumborum will contract with glutes and hamstrings if shoulder move in front of the hips.
- If the shoulder moves too much back, abdominals and obliques will activate.
- Right sided core muscles will contract, if the right hip is raised and an attempt is made to keep the torso vertical.