If you use the posterior leg muscle chain correctly while jogging, you can not only gain speed, but also practice injury prevention. For runners, the balance between the posterior and anterior thigh muscles is essential to preventing injuries. Most pulled muscles occur in the posterior muscle compartment (hamstrings) and can be avoided. When you increase your speed, run for too long, or run downhill, the posterior thigh muscles frequently become overloaded, thus leading to a pulled muscle or even torn muscle fibres. The better these muscles work, the more energy efficient they are. When the foot strikes the ground, the gluteal muscles pull the leg backwards or the body forwards. This naturally requires the right posture: an upright spine and a slight lean forward. This enables the posterior chain to work optimally.
A poor posture (kink in the hips and forward lean from the waist) can keep the posterior chain permanently overstretched. If the focus is only placed on the anterior thigh muscles (quadriceps) during strength training, this will inevitably lead to an imbalance. Unfortunately, the importance of this posterior chain seems to be constantly forgotten.
A lot of sitting can often put a spanner in the works. If you sit a lot, the front of your groin shortens and first needs to become more flexible. Stretching the leg backwards should only be done from the hip joint. The pelvis remains upright and the groin open. This relieves the lower back. Flexibility is a basic prerequisite for gaining strength. Below is a very simply hip flexibility stretch you can do before any run or strength workout.
In the running motion, there are 4 phases.
1. Forward swing phase
The objective of this phase is to prepare for an active foot strike. The recovery leg swings through, but in a less pronounced way than in sprinting (in sprinting it is sometimes referred to as drive the leg through). Once the leg has passed to the front of the body with the hip flexed, the leg will lower and the knee will extend, so the shin becomes vertical. To some degree the lower leg will act like a pendulum around the knee, so that the weight of the foot and lower leg will swing the lower leg underneath the body.
As the foot then moves down you need to control the foot placement on the ground, with the foot facing forward, and ready to land close to the centre of gravity and under the knee. A useful cue is to 'step down' providing for the active ground contact.
2. Foot contact phase
The foot takes the load under the centre of gravity, so the centre of mass is already above the foot.
Foot contact generally initiates on the outside edge of the foot, around the mid-foot. It should be noted that this can be hard to determine with modern training shoes that have more cushioning in the heel. Additionally, the point at which the foot is weight bearing is what we are interested in, not just where it appears the training shoe is in contact with the floor.
Once the foot has landed, it needs to take the load of the body, and this is where the knee and ankle will flex to allow the foot to pronate and take the weight of the body, also storing up the ‘elastic energy’.
A more useful cue can be that when the foot takes the load we are looking for a vertical shin.
3. Propulsion phase
After the foot has taken the load of the body the forward propulsion phase is responsible for utilising both passive (stored elastic energy) and active (muscle contractions) to produce the force required to drive the body forward. Whilst it is a continual action this phase has three distinct elements:
The foot has taken the full load of the body, elastic energy is stored. The ankle, knee and hip are flexed.
Your weight rolls over the foot to the big toe, due to release of the stored passive energy and also muscle contractions. As well as the calf and achilles, a key area of movement is the extension of the hip. To achieve good hip extension there needs to be no restriction in the abdomen, this is another reason for not 'sucking in the core' which restricts the ability of hip flexors to extend.
At this point the foot is leaving the floor, and you should be aiming for a combination of an upward and forward trajectory.
4. Recovery phase
This phase begins with the foot breaking contact with the ground, with the trailing leg flexing at the knee and the heel moving up towards the backside. The degree of flexion at the knee is dependent on running speed and the force applied during the propulsive phase. It will also be restricted by the flexibility of the participant.
With good run biomechanics this phase should happen passively, or put differently as a reaction to the propulsive phase. The degree to which this may happened can again depend upon race distance and individual characteristics of the athlete.
Therefore, there shouldn’t be a need for you to focus on drawing up your heel. Once the hip has extended fully in the propulsive phase it has effectively been stretched. The reflex action for this is that the hip flexors will shorten and the upper leg(femur) will be drawn forward. At the same time the lower leg flexes at the knee and ankle; this is where the foot get drawn up towards the glutes as a reaction to the hip stretching (propulsive phase) and then shortening (recovery phase).
Strengthening the hamstrings contributes significantly to optimising your running style. Straight leg deadlifts and Nordic Ham Curls are great exercises for this