Peroneal Muscle Activity During Stable and Unstable Load Exercises
Written by Ben Bunting: BA(Hons), PGCert. Sport & Exercise Nutrition. British Army Physical Training Instructor.
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The peroneal muscle is a long muscle running along the lateral axis of the foot. It inserts on the first metatarsal bone head.
The purpose of this study was to explore peroneal muscle activity during stable and unstable load exercises.
Specifically, surface electromyography (EMG) was collected from the tibialis anterior (TA), peroneus longus (PL) and soleus (SOL) muscles in unipedal and bipedal positions with or without elastic tubing as resistance on various unstable (uncontrolled multiaxial and uniaxial movement) and stable surfaces.
What's the Peroneal Muscle?
Peroneal Muscle is a large muscle and tendon that makes up the lateral compartment of the lower leg.
It is a strong stabilizer of the ankle joint and also acts as a pulley system to help generate a greater amount of force when the muscle contracts.
This muscle is the most lateral muscle in the lower leg and provides a dynamic stabilizing force on the lateral aspect of the ankle.
It is critical in maintaining stability of the ankle during stance phase of gait, as it helps to prevent excessive inversion of the foot.
Overuse or injury of the peroneal muscles and tendons can cause peroneal tendinopathy to develop.
The tendons may become thick, enlarged, and possibly swollen. This condition usually occurs over time as a result of repetitive stress on the area and is commonly seen following an untreated ankle sprain.
Your PT or physiotherapist may prescribe exercises that work your peroneal muscles to strengthen them and improve your balance.
They may also use neuromuscular electrical stimulation (NMES) to promote proper muscular function and contraction.
A PT may also suggest using ice to control inflammation and a heat wrap to promote circulation. This will decrease pain and swelling and assist in your recovery from the injury.
Improving balance and proprioception is another important part of a peroneus rehabilitation program.
Performing single-leg standing exercises, such as balancing on one foot with no support or stable object, can improve balance and help to reduce the risk of future peroneus problems.
Importance of stability
Stability is the ability to resist sudden and dramatic changes in motion or position. This property of a system is important to mechanics and dynamics, but stability can also be found in everyday systems such as airplanes or buildings.
In the context of exercise, stable means that the movement will occur with minimal alterations in the body's posture and balance.
This is particularly true when performing weight-bearing exercises in which the musculature must be maintained in a static position to allow for the movement.
However, in unstable load exercises such as lunges, peroneal muscle activity increases significantly.
This increase in muscle activity is due to a variety of factors, including the increased demands placed on the peroneus longus muscles to stabilize the ankle and to prevent lateral ankle instability during performance.
This increased activity is related to the fact that the peroneus longus muscle is responsible for preventing lateral ankle instability during walking, as well as during functional tasks such as standing on uneven surfaces or climbing stairs.
The peroneus muscle is also known to have a role in maintaining medio-lateral balance in the frontal plane, especially during single support phases of walking.
The peroneus muscle is also responsible for generating force during an unstable load exercise, as the muscle will be activated to produce a certain amount of force against an uneven surface such as a bench or a dumbbell.
It is possible that the peroneus muscle can be trained to generate more force when performing an unstable load exercise.
One way to achieve this is through a prolonged IRT program that provides significant strength training enhancements in the short term (approximately 7-8 weeks).
Sparkes and Behm12 demonstrated that both unstable and stable trained groups achieved increases in force, static balance and functional performance with an average effect size of 0.98.
Ankle eversion
Ankle eversion is one of the most common ankle injuries. It is caused by the flexion of the foot during an unnatural movement or a fall.
It is also commonly associated with a fibula fracture called a Pott’s fracture. However, it is unclear how the ankle sprain mechanism works or what factors contribute to this type of injury.
The first step in understanding the mechanism of an eversion ankle sprain is to understand the muscle activity that occurs during this motion.
The peroneus longus is a key muscle involved in this motion. It is also a very powerful muscle that has the potential to tear during an ankle sprain.
Therefore, it is important to know how this muscle is activated during stable and unstable load exercises. It is also important to know how this muscle changes following fatigue.
This study evaluated peroneus longus muscle activity during maximal voluntary isometric contractions (MVIC) performed against resistance. These MVICs consisted of plantar flexion, dorsal flexion, and ankle eversion and inversion movements.
During MVICs, subjects were seated on chairs that provided an adjustable height so that their knees could be at a 90deg angle. They were then asked to perform a single MVIC on each leg.
The eversion and inversion muscles were measured by using surface electrodes and an accelerometer attached to the body.
MVICs were performed at pre-fatigue and post-fatigue conditions to normalize the EMG signal and to compare muscle activity between stable and chronically unstable ankles.
Results showed that the pre-fatigue mean amplitude of m. peroneus longus was lower in both stable and chronically unstable ankles, but there were no significant differences between groups.
The amplitude of the peroneus longus was also decreased during post-fatigue compared to pre-fatigue for both stable and chronically unstable ankles.
These results indicate that the peroneus longus muscle is a critical component of ankle joint function and stability during eversion and inversion.
The findings of this study have implications for rehabilitation and injury prevention programs.
They may help explain the pathophysiology of ankle instability and identify compensatory mechanisms that athletes with chronically unstable ankles use to maintain their ankle stability.
Plantar flexion
Plantar flexion, or pointing the tips of your toes down toward the ground, is a simple movement that takes a lot of coordination. It requires muscles in the calf, ankle, and foot to make it happen.
Performing daily activities like standing on tiptoes, stepping up onto a stool, or walking on rough surfaces requires the use of these muscles.
Without them, you could easily fall or hurt yourself, and this is why it is so important to regularly do plantar flexion exercises.
Toe-walking and calf raises are simple plantar flexion exercises that you can do in the comfort of your home. These exercises will strengthen the calf and heel muscles that control plantar flexion and help you avoid injuries in this area.
These stretches will also help you improve your overall flexibility and strength, which can make it much easier for you to protect your ankles.
If you have an injury to your ankle or foot, it is essential to do physical therapy and regular exercise to strengthen and protect this part of the body from future problems.
The plantar flexors are the muscles that bend your foot away from your body, so they are essential to maintaining your balance and stability during everyday activities.
These muscles are located in the back of your legs, around your shin bones and ankle bones, and on the tops and bottoms of your feet.
In addition to these muscles, other muscles in your lower legs and feet also play an important role in plantar flexion. They include the peroneus longus, gastrocnemius, soleus, and triceps surae.
According to one study, the activity of the plantar flexors during stable and unstable load exercises was significantly higher after 3 weeks of training.
In addition, the margin of stability at release was improved after 3 weeks of training compared with before the intervention.
In the same study, a toe-tap exercise was used to measure the maximum voluntary inversion contraction (MVIC) of the plantar flexors and the abductor hallucis.
The MVIC was determined before, after 3 weeks of training, and after 6 weeks of training. In addition, the balance recovery performance was evaluated by a forward fall test and by a strength measurement.
Dorsiflexion
Dorsiflexion is a backward bending movement at the ankle and wrist. The muscles that control dorsiflexion include the tibialis anterior, extensor digitorum longus, extensor hallucis longus, fibularis tertius and plantaris.
It is important to keep your dorsiflexion strong and flexible for a number of reasons. It is an essential part of efficient running form, it can reduce the chance of falling during a run, and it helps runners produce greater speed.
The most common causes of poor dorsiflexion are genetics and injury. Injuries can limit the range of motion in the ankle joint and cause scar tissue to form.
This limits the way your foot moves and may make it difficult to move in other areas of the body, such as squatting or lunging.
To improve your dorsiflexion, you should stretch your feet and ankles before exercise and perform a few dorsiflexion exercises during your workout.
You can also try a knee to wall test, where you place your big toe three to five inches away from a wall and then bend the knee of the same leg forward.
If you can touch the wall with your knee cap, you have good dorsiflexion.
Improving your dorsiflexion can help you in all aspects of training, especially squatting and sprinting. It can also reduce the risk of injuries in the knee, hips and low back areas because it prevents overpronation and valgus when you walk.
If you have poor dorsiflexion, it’s important to work on strengthening the tibialis anterior and extensor digitorum longus muscle. These two muscles are located on the inside of the lower leg and help you to walk.
In addition, you should strengthen the flexor digitorum longus and flexor hallucis longus muscles on the outside of your lower leg, which help you to bend the knee of your opposite leg when you walk.
You can strengthen these muscles with a few simple exercises, including walking lunges and squatting.
Poor dorsiflexion is a common cause of knee pain and injury. It can make it difficult for a person to properly fire their glute muscles and can lead to weak calf muscles, which in turn can affect the way they walk.
Conclusion
The peroneus muscle is an important component of ankle stability, and is often the first to be affected after ankle sprains.
Its activity can be impaired during a chronic instability episode, which could contribute to recurrent episodes of instability and lead to subsequent ankle injuries.
It is therefore necessary to restore dynamic peroneal muscle activity to maximize ankle stabilization, thereby reducing the likelihood of injury.
