Plantaris
Original Editor - Samuel Adedigba
Top Contributors - Samuel Adedigba, Deepmala Jadwani, Kim Jackson and Eugenie Lamprecht
Description
The Plantaris muscle is a small muscle with a short belly and long slender tendon that is located at the posterior compartment of the leg and along with the Gastrocnemius and Soleus muscles, forms the Triceps Surae[1]. The long, thin tendon of plantaris is nicknamed the freshman's nerve[2], as it is often mistaken for a nerve by first-year medical students during dissection[1]. Morphologically presents high variability[3], absent in 10% indivisuals, so its status as vestigial muscle should be should be reconsidered[4].
Anatomy
Origin
It originates from the lower part of the lateral supra-condylar line of the femur and from the oblique popliteal ligament of the knee joint and the muscle belly crosses the popliteal fossa inferomedially. In the proximal third of the leg, the muscle belly is situated between the popliteus muscle anteriorly and the lateral head of the gastrocnemius muscle posteriorly. Its long slender tendon courses distally between the medial head of the gastrocnemius muscle and the soleus muscle in the middle third of the leg[5].
Insertion
The muscle inserts medially, in association with the Achilles tendon on the calcaneus[6], or independently on calcaneus.
Nerve
Neural innervation of the plantaris muscle is provided by the tibial nerve (S1, S2)[6].
Artery
Blood supply to the plantaris muscle is from the popliteal artery[5].
Function
In terms of function, the plantaris muscle acts with the gastrocnemius but is insignificant as either a flexor of the knee with weak plantar flexion of ankle[6], when the foot fixed, or a dorsiflexion of the ankle if the foot is free[5]. It has been considered to be an organ of proprioceptive function for the larger, more powerful plantar flexors, as it contains a high density of muscle spindles[7].
Clinical relevance
Even though it is a largely unremarkable muscle, the plantaris tendon is clinically significant because of its potential use as a graft due to its length and tensile strength. Removal of the plantaris muscle does not typically hinder the patient’s lower extremity function in the presence of a normal soleus and gastrocnemius[7]. Also, pathology of the plantaris muscle and tendon is an important differential diagnosis for calf strains and any pain arising from the proximal posterior aspect of the leg.
Assessment
Palpation of the muscle belly is possible in the popliteal fossa as well as along the medial aspect of the common tendon of the triceps surae group. With the patient prone and the leg flexed to approximately 90 degrees, the distal hand of the practitioner covers the heel while the forearm is applied against the plantar aspect of the foot, allowing a simultaneous resistance to plantarflexion of the foot and flexion of the knee. The muscle is palpated in the popliteal fossa, medial and superior to the lateral head of the gastrocnemius muscle[2].
Management
Acute phase of healing
Over time, Soft Tissue Injuries treatment guidelines have evolved from RICE[2] to PRICE and POLICE. Newer approach called PEACE and LOVE. PEACE helps with immediate care, and LOVE helps with ongoing care[8].
Sub-acute phase of healing
Following immobilization, progressive passive, active, and resisted movements may commence within the pain limits. Manual therapy such as soft tissue mobilization, myofascial release and/ or active release techniques can also be initiated in this phase of healing. Manual therapy is essential for optimal collagen fibre growth and realignment[2].
Progressive strengthening is also important in this phase and should be approached according to the isometric, isotonic and isokinetic exercise principles and within the individual's pain limits[2].
Sub-acute to chronic phase of healing
Progressive strengthening and ROM exercise continue in this phase, however, proprioceptive, balance and sport-specific rehabilitation can also be initiated in this phase[2].
Resources
See Also
References
- ↑ 1.0 1.1 Moore KL, Dalley AF. Clinically oriented anatomy. 5th Ed. Lippincott Williams & Wilkins: Philadelphia. 2006; p 648–649
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 Spina AA. The plantaris muscle: anatomy, injury, imaging, and treatment. The Journal of the Canadian Chiropractic Association. 2007 Jul;51(3):158.
- ↑ A. Smedra1, L. Olewnik2, P. Labetowicz, A bifurcated plantaris muscle: another confirmation of its high morphological variability? Another type of plantaris muscle. Folia Morphol. Vol. 80, No. 3, pp. 739–744, 22 August 2020]
- ↑ Ł. Olewnik, K. Kurtys, B. Gonera, Proposal for a new classification of plantaris muscle origin and its potential effect on the knee joint. Annals of Anatomy - Anatomischer Anzeiger, Volume 231, sept 2020, 151506
- ↑ 5.0 5.1 5.2 Henry Gray (1825–1861). Anatomy of the Human Body. 1918. 8c. The Muscles and Fasciæ of the Leg
- ↑ 6.0 6.1 6.2 Duke Orthopaedics, Wheeless Textbook of Orthopaedi. Muscle Tendons, Plantaris.
- ↑ 7.0 7.1 Sharma S, Khullar M, Bhardwaj S. Unilateral Accessory Plantaris Muscle: A Rare Anatomical Variation with Clinical Implications. Global Journal of medical research. 2015 Jan 21.
- ↑ Dubois, Blaise, Esculier Soft-tissue injuries simply need PEACE and LOVE British Journal of Sports Medicine, vol 54, 2019.
- ↑ Dr Nabil Ebraheim. Anatomy Of The Plantaris Muscle - Everything You Need To Know. Available from: https://www.youtube.com/watch?v=OWhZVCk2TKA [last accessed 6/27/2018]
- ↑ Becky Fidler. Muscle Functions: Plantaris. Available from: https://www.youtube.com/watch?v=drb-bDot8qA [last accessed 6/27/2018]