What are plyometrics or plyometric training ?
In the simplest definition, plyometrics refers to jump training.
A key component of many sports, such as basketball, soccer, and tennis, plyometric training can enhance athleticism, strengthen the most powerful muscles in your body, and more.
Here’s a breakdown of the benefits of plyometric exercises, and how to safely add them to your workout routine.
What do Plyometrics do ?
Plyometric training is mainly associated with lower limb training and rehab and is a way of developing speed and power by training the “spring ” like qualities of the neuro – muscular -tendinous system. Its not just for athletes or sports people and has implications in the rehabilitation of most lower limb tendon complaints such as Achilles tendinopathy or plantar fasciopathy.
If we use a spring as an analogy of what happens to the muscle tendon unit in plyometrics the idea is based on the following phases :
- Eccentric phase :The muscle -tendon unit resists load from a lengthened position to a shortened position. Much like how we squash the spring. In this phase we absorb energy.
- Amortization phase: Then there is a slight pause in the shortened position where the energy is stored creating potential energy. To much time in this phase leads to loss of energy and loss of plyometric effect.
- Concentric phase :This energy is released into kinetic energy when we spring back into a lengthened position.
What are the benefits of plyometrics in rehab and training ?
This type of training in rehab settings is probably more suited towards mid to end stage rehabilitation. However its an essential component as it has benefits in the following qualities:
- Increases tendon stiffness and strength, important in long term tendon health and function.
- improves “shock absorbency” at joints.
- improved running speed, agility, and quickness.
- Injury reduction.
- Improved power, helps increase jumping height and distance.
Plyometric training and rehab of ankle injuries:
Research has demonstrated that with ankle injuries by incorporating plyometric training / exercises alongside more traditional strength and balance exercises that better outcomes are achieved.
Incorporating this training showed improvements in:
- ankle stability.
- static and dynamic postural control.
- Joint position sense.
A selection of exercises in this study are shown below:
Plyometric training and knee injuries and ACL reconstructions
A recent review on the use of plyometrics in ACL injuries has stated that integrating this type of training into rehabilitation will enhance:
- Strength of the knee and lower limb.
- Movement quality in lower limb and total body .
- Explosive neuromuscular function and power.
- Agility and athletic performance.
If you need to know more about ACL rehab check out our post here
How to perform Plyometrics
Plyometric should be introduced at an appropriate level of intensity and complexity relative to the individuals stage of rehab and built up to be specific to the demands of their chosen activities.
The Optimum Performance Training (OPT ™) model provides a sensible and stepwise progression for athletes using plyometrics.
This model safely progresses an athlete through the different phases of plyometric training to minimise risk of injury and maximize its effectiveness. It can be adapted and used in a rehabilitation setting as well as a performance training setting.
- Plyometric intensity is based on the intensity of efforts, the vertical and/or horizontal momentum prior to ground contact,
- Ground contact time: the shorter the time you are on the floor better . Think about the kids game the floor is lava.
- Technique : how a person technically performs the task will influence joint loading.
- The surface or environment on which they are performed on, this is relevant to minimise joint forces and loading in the early stages and also to increase specificity in late stage / return to sport stage.
Plyometric Stabilisation phase
Time to play musical statues !
Exercises in the stabilization level of plyometric training involve little joint motion. So they are likely to be small range movements focusing on postural control in the landing or ground contact phase.
The exercises in this phase are concerned with establishing;
- Develop technique of movements to come later in the program.
- Dynamic postural control. Looking for good trunk , hip knee ankle alignment is important for good technique and reducing risk of further injury.
- Good landing and take off mechanics. Hold for around 3 secs on landing .
- Develop the force / shock absorbency of the region. Try and be quiet on landing
- low impact and small amplitude / range of motion exercises. Combine landing exercises with skipping and small low intensity jumping games.
As a guide these exercises are programmed into rehab as follows:
The exercise intensity should be at a level where the individual can land quietly on the ball of the foot and maintain a credit card space underneath the heel.
2-4 times per week 3-4 sets of 5 – 8 repetitions / ground contacts per session .
If adding skipping this will lead to more repetitions / ground contacts, but they are relatively low intensity.
The first part of this video demonstrates stabilisation and entry level plyometric exercises:
.Plyometric strength phase
Its time to play the floor is lava !
The aim of the strength phase is to improve the following qualities:
- dynamic joint stabilization required to prevent injury and produce more force.
- Increasing dynamic strength.
- rate of force production.
- Improve movement patterns.
Below is a video on examples of lower limb strength based plyometric exercises:
The exercises in this phase are performed in a more repetitive fashion by spending shorter amount of time on the ground.
The exercises are more specific to demands required by the individual in terms of movements and speed of execution.
From a perspective of volume it is probably wise to be looking at 20-80 contacts per session , broken down into sets of 5-8 repetitions.
Plyometric power phase
In the power level of plyometric training, exercises involve the entire spectrum of muscle
actions and contraction velocities important for integrated, functional movement.
These exercises are performed as fast and as explosively as possible and volume of exercises is kept lower to optimize rest as these are more intensive efforts on the system.
As they are higher intensity this may only involve 10 – 50 contacts per session broken into sets of 3- 5 repetitions.
Below is a video on examples of lower limb power plyometric exercises:
When to introduce plyometrics
There should be a gradual increase in intensity and specificity of the exercises throughout using plyometrics in a program. The OPT model provides a sensible stepwise progression through the phases required in rehabilitation.
Start small, slow and simple and gradually build up the volume of how much jumping you do. There’s not much to be gained from going from zero to hero apart from further injury.
It also has to be integrated in relation to the healing stage of tissue that has either been repaired or injured as you don’t want to disrupt the bodies healing mechanisms.
We tend to look at integrating our plyometric based exercises into an individuals rehabilitation. This allows for development of all facets of their needs in the session.
Mixing strength based work with power, speed and agility, contrast training as it was once known , tends to show better results and is more manageable for most from a time perspective.
If you need help with your rehab following injury feel free to get in touch with one of our team here
References:
Recommendations for Plyometric Training after ACL Reconstruction – A Clinical Commentary , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8169025/#
