Understanding Muscle Dynamics is More Than Just Strength Training
In fitness and sports performance, there’s a common misconception that muscle power is all about the big primary mover muscles – think pecs and glutes. However, true strength and efficiency come from a harmonious balance between “mover muscles” and “stabiliser muscles.
Stabiliser muscles are also known as “tonic” muscles, because while working, and even at rest, they maintain a continuous level of tone. This makes them suited to stabilising your joints.
Mover muscles are also known as “phasic” muscles, because the majority of their activity happens in separate phases.
Both types of muscles can be strong or weak, but they difference in the way they work means you need to train them with different methods.
It also means that if one of those two types isn’t working effectively, they other type also loses effectiveness as a result.
The Unsung Heroes: Stabiliser Muscles
Stabiliser muscles, too often overlooked, play a vital role in maintaining joint alignment and stability. These muscles work continuously to provide a steady foundation, ensuring that the more visible mover muscles can function optimally.
Examples of Stabilisers and Movers:
- Shoulder Stability: The posterior rotator cuff (infraspinatus and teres minor) stabilises, while the latissimus dorsi or pectoralis major primarily move the joint.
- Hip Balance: The gluteus medius and minimus (with the adductors on the inner thigh) act as stabilisers, and the gluteus maximus or hip flexors (such as iliopsoas and rectus femoris) serve as prime movers.
Dual-Role Muscles: Quadriceps and Soleus
- The quadriceps and soleus muscles showcase dual functionality, acting both as stabilisers and movers, depending on the context of the movement, they illustrate the complexity of muscle dynamics.
Agonists and Antagonists: A Delicate Dance
The relationship between agonist and antagonist muscles is key to optimal performance. When agonists (like the biceps during a curl) are overworked, they can inhibit their antagonists (like the triceps), leading to imbalances and reduced muscle power.
Facilitation and Inhibition: A Closer Look
- Facilitated muscles are constantly tight, reducing the effectiveness of their antagonists.
- Pre-fatigue means these muscles are already using energy before exertion, akin to driving a sports car with a speed limiter.
- Tetany and Metabolic Crises: Overworked muscles are prone to cramping and reduced blood flow, impacting overall muscle health.
The Danger Zone: What Happens When Things Go Wrong
Muscle injuries are a common concern in both athletic and everyday activities, and understanding their mechanics is crucial. One such injury is the pulling of a hamstring, which can occur due to miscoordination between different types of muscles in the body.
Phasic and Tonic Muscles In Context
- Phasic Muscles: These are primarily used for dynamic, powerful movements. They are generally fast to contract and quick to fatigue – essentially, they are for sprints and short bursts of power.
- Tonic Muscles: In contrast, tonic muscles are used for posture and are more endurance-oriented. They are slower to contract, and slower to fatigue – essentially, they are for protecting your joints from being yanked everywhere while the giant power muscles do the large, gross movements.
The Miscoordination Problem
- Facilitation and Inhibition: In a well-coordinated system, phasic and tonic muscles work in harmony. Your nervous system is able to efficiently coordinate movements so that you can deliver maximum power while maintaining solid stability.
However, issues arise when one type of muscle becomes overly facilitated (overactive) while the other is inhibited (underactive). This imbalance can lead to undue stress on certain muscles.
- Hamstring Pull: When phasic muscles like the hamstrings are doing their powerful movements with an inhibited tonic stabiliser system or an out-of-whack agonist-antagonist balance, it increases the risk of pulling or straining the muscles.
This is especially common in activities requiring sudden bursts of speed or power, such as sports like soccer. It can also come into play when a person is not well-trained, and overdoes things. This could even be in an emergency situation, such as lunging to avoid being hit by something.
The Extreme Case: Avulsion Fractures
In the most extreme circumstances, an imbalance and overexertion can lead to an avulsion fracture.
Avulsion fractures can occur when a muscle or tendon pulls so hard on the bone to which it is attached that, rather than the muscle or tendon breaking, it tears off a piece of the bone instead. It’s a severe injury that often requires immediate medical attention.
Understanding the balance and coordination between phasic and tonic muscles is essential in preventing injuries like hamstring pulls or, in severe cases, avulsion fractures. Regular training, nervous system conditioning, proper warm-up routines, and awareness of one’s body mechanics can help to mitigate these risks.
There is really no point at all in neglecting your stabiliser muscles and training the big power muscles if all they end up doing is injuring you.
Training for Harmony: A Guide to Balanced Muscle Health
- Assess and Recognise: Start with a professional assessment to identify imbalances and miscoordinations.
- Targeted Stretches and Strengthening: Focus on relaxing any tight, facilitated muscles and strengthening any weak, over-stretched, inhibited antagonists.
- Incorporate Stabiliser Training: Engage in exercises that specifically strengthen stabiliser muscles, such as core stability workouts, rotator cuff activations, and single leg balancing.
Effective Stretching Techniques
- Opt for sequential 2-second stretches, which are more efficient and effective than single long-hold stretches. These are especially suitable for those who prefer quick routines or those who get easily bored!
Active Lengthening and Reciprocal Inhibition
- Engage in active lengthening exercises, like slow tempo Romanian deadlifts, to train muscles in their eccentric (lengthening) phase.
- Utilise reciprocal inhibition during stretches by actively engaging the opposite muscles. For example, stretch your pecs by actively pulling your arms backwards, using your upper back muscles to do so.
The Ultimate Goal: Full-Range Strength and Control
The objective is to achieve a state where both stabiliser and mover muscles are optimally trained, and your agonist & antagonist muscles are balanced.
This ensures not just peak performance but also the safety and longevity of your physical health, crucial for everyone from elite athletes to everyday fitness enthusiasts.
Check out my YouTube channel as well, I talk about reciprocal inhibition there and also have a bunch of sequential stretching exercises peppered throughout. Here’s the link:
If you have any questions after this, please do ask away. I can use them to further develop my blog posts!