GENERAL INFORMATION
The fibularis muscles, also known as peroneal muscles, are located in the lower log’s lateral (outer) compartment. These muscles play a significant role in ankle eversion (moving the foot outward) as well as provide stability to the ankle joint.
ORIGIN
The fibularis muscles have their origins in different areas:
- Fibularis longus: Head and upper two-thirds of the fibula (smaller lower leg bone).
- Fibularis brevis: Lower two-thirds of the fibula.
INSERTION POINT
The fibularis muscles have the following insertion points:
- Fibularis longus: Base of the first metatarsal bone as well as medial cuneiform bone of the foot.
- Fibularis brevis: Base of the fifth metatarsal bone of the foot.
MAJOR ARTERIES
It receives its blood supply from branches of the fibular artery, including the anterior lateral malleolar artery.
NEURAL INNERVATION
The fibularis muscles are innervated by the superficial fibular nerve (also known as the superficial peroneal nerve), which arises from the common fibular nerve. The superficial fibular nerve provides motor innervation to these muscles, allowing them to contract as well as produce movement.
TRIGGER POINT
Trigger points can develop in these muscles, causing pain as well as discomfort in the lower leg and foot. It may be associated with muscle tension, overuse or injuries.
CONCENTRIC FUNCTION
The concentric function of these muscles involves the shortening or contraction of the muscles. This function is primarily responsible for ankle eversion, moving the foot outward.
ECCENTRIC FUNCTION
The eccentric function of these muscles refers to the controlled lengthening of the muscles while resisting an external force. It is involved in controlling ankle inversion (moving the foot inward) as well as decelerating the foot during gait.
ISOMETRIC FUNCTION
The isometric function of these muscles involves contracting the muscles without any change in length. Isometric contractions of these muscles occur during activities that require stability as well as maintaining the position of the foot.
RELATED MUSCLE-SCIENTIFIC NAMES
The following scientific names know the fibularis muscles:
- Musculus fibularis longus
- Musculus fibularis brevis
ANTAGONIST MUSCLES
The antagonist muscles to the fibularis muscles are:
- Tibialis Anterior: Responsible for ankle dorsiflexion (lifting the foot upward)
- Tibialis Posterior: Involved in ankle inversion
COMMON INJURIES
- Fibularis Tendinitis: Inflammation of the tendons of the fibularis muscles, often caused by overuse or repetitive stress. Symptoms include pain and swelling along the outer lower leg.
- Ankle Sprains: Injuries to the ligaments of the ankle which can affect these muscles and their tendons. Symptoms include pain, swelling and instability in the ankle.
- Stress Fractures: Small cracks or breaks in the fibula bone associated with excessive stress on these muscles. Symptoms include localised pain and tenderness along the fibula.
EXERCISES
- Ankle Eversion Exercises: Move the foot outward against resistance, such as a resistance band, to target the fibularis muscles. Strengthens the muscles and improves ankle stability.
- Resistance Band Exercises: Wrap a resistance band around the foot and perform ankle eversion exercises. It provides targeted resistance to strengthen these muscles.
- Ankle Stability Exercises: Engage in exercises that challenge the stability of the ankle joint, such as standing on one leg on an unstable surface. Activates and strengthens these muscles, enhancing ankle stability.
- Lateral leg Raises: Lie on your side and lift the top leg upward, hold for a moment, then lower it back down. Strengthens the lateral muscles of the lower leg, including the fibularis muscles.
- Single-Leg Balance Drills: Stand on one leg and maintain balance, optionally incorporating movements or reaching with the opposite leg or arm. It improves balance and engages the fibularis muscles for stability.
STRETCHES
- Ankle Inversion Stretch: Gently turn the foot inward (inversion) to stretch the fibularis muscles. It improves flexibility and relieves tension in the fibularis muscles.
- Standing Calf Stretch: Lean against a wall with one leg extended behind and the heel on the ground, stretching the calf muscles. Indirectly stretches the fibularis muscles while targeting the calf muscles.
- Seated Ankle Eversion Stretch: Sit with one leg over the opposite knee and gently press the raised foot downward and outward. Directly stretches the fibularis muscles, enhancing flexibility.
- Wall-Assisted Ankle Stretch: Place the toes of one foot against a wall and lean forward, keeping the heel on the ground. Stretches the lower leg muscles, including the fibularis muscles.
- Foam Roller Stretch: Use a foam roller to gently massage and stretch the thigh fibularis muscles. It helps release tension and improve flexibility in the fibularis muscles.