Skin sensors and musculoskeletal sensors including nerve fibers and Golgi nerve organs (GTOs) are the main sensors that regulate the relative level of motor and muscle activity. They respond to touch vibration pressure and stretch their skin changing length a function of muscle and tendon strength. Skeletal muscle length and tension are controlled through proprioception in order to coordinate motor control. This article will focus on ankle proprioception and how it can be used in the rehabilitation of ankle injuries.
What Is Proprioception?
Proprioception is a fundamental change in the sensory range of touch that affects the perception of joint movement (kinesthesia) and joint position (sensitivity to joint position). When neurological changes occur, sensory nerves are supplied by the joint nerves and tendons of the cutaneous tissue proprioceptive feedback to the central nervous system (CNS) via physiological mechanisms. The route taken depends on the type of signal being transmitted. Communication and proprioceptive information via the posterior column-medial lemniscal pathway reaches the CNS. Muscles of the spinal cord pathways carry information about pain and inflammation. In addition, the visual and vestibular centers provide afferent information to the central nervous system about body position and balance.
Proprioception is governed by body receptors. Because it is directly connected to the brain through nerves an individual who is visually impaired is aware of his or her bodily functions. If there is a change in the longitudinal joint position or speed of movement of the ankle The CNS uses this information to coordinate movement and perform gait.
Mechanoreceptors, thermoreceptors, and nociceptors are all cutaneous sensory receptors. There are six skin mechanoreceptors: Merkel discs Meissner corpuscles Pacinian corpuscles Ruffini endings and C-fiber low threshold mechanoreceptors. Hair follicles also belong to this group and are responsible for Detect light touch. Meissner bodies are located in the dermal papillae and detect subtle touch and vibration. High frequency vibrations and touch are also responsible for the Pacinian corpuscles located in the dermis. Ruffini bodies detect stress from stretch skin. The basal epidermis is home to the Merkel discs responsible for detecting structure and texture. Finally, the C Fiber LTM detects light touch. 
The brain receives strong proprioceptive messages through receptors located in the muscles. These receptors are called muscle spindles.  Muscle spindles are considered the most important proprioceptors. They are activated by muscle stretch and exhibit high sensitivity Small and rapid changes in muscle length. This mechanical stretch sensation is transmitted to the spinal cord via the dorsal root ganglia, and the central nervous system receives this information via afferent nerve fibers. 
Proprioception and Ageing
Several studies have found that aging negatively affects muscle spindles and their neural pathways, resulting in decreased sensitivity and sharpness. 
In a study by Skinner et al. found that older subjects had significantly worse proprioception in response to passive movements compared to the younger group. Kaplan et al observed age-related changes in proprioception and confirmed a decrease in proprioception during older individuals compared to younger ones.
At the peripheral level the age-related decline in proprioception involves changes in spindle muscle formation and function as well as deficits in the processing of sensory input. The structural changes include a decrease in the total number of nerve fibers and nuclear chains threads per spindle and the thickness of the spindle capsule. Processing deficit is characterized by myelin abnormalities axonal atrophy and decreased nerve conduction velocity. Decreased proprioception is caused by the following changes in the central nervous system:
- Progressive loss of dendrite structure in the motor cortex.
- Loss of muscle and nerve mass.
- Neurochemical changes in the brain
Intrinsic foot muscles
Proprioception and Muscles of the Foot
Panjabi was the first to propose the theory of core stability. It describes the functional dependencies between the passive (skeletal and joint systems) active (muscles and tendons) and neural (sensory receptors) subsystems responsible for spinal movement and stability. The same is true the concept applied to the ankle and foot was introduced by McKeon in 2013. The concept of the foot muscles describes the role of the muscles of the foot. It is a functional connection of the plantar intrinsic muscles to both sides of the foot.  .
The foot active subsystem:
- Offers local dynamic support
- Senses foot position
- Provides postural control
- Actively controls balance in standing position
- Controls foot position on uneven terrain
- It facilitates greater recruitment of muscles when additional loads are applied
Researchers continue to investigate the role of foot structures in proprioception. The contents are supposed to provide immediate sensory information when there is a change in foot alignment. Furthermore it has been stated that these muscles respond well to training and sensitivity to deformation can be changed. Muscles in the body are vulnerable to fatigue and according to Hiemstra et al, muscle fatigue can adversely affect sense of joint position at different locations in different lower extremities.
Visual / Vestibular System and Proprioception
The vestibular system is an important accessory sensory system essential to our cognitive perception of movement and orientation in space.
Vision plays an important role in the ability to feel one’s body in space. It is necessary for precision of movement but not necessary for one to understand body ownership. The vestibular system regulates head movement. This is fundamentally emotional schedule as:
- The posture of the head greatly influences the human body. Small head movements can cause postural and sensory instability.
- Findings suggest that abnormal head position alters muscle function and proprioception.
- The rapid movement of the head by compensatory eye movements contributes to proprioception and posture.
Proprioception and Ankle Injury
When trauma occurs to nerves it can disrupt the afferent connection of nerve cells that carry sensory information from the body part to the brain. This can lead to proprioceptive deficits. Several studies investigated the relationship between toes proprioception does not ankle resists: .
- Payne et al. found that ankle proprioception can predict ankle injury in college basketball players.
- Fu et al found that a group of basketball players with poor ankle proprioception exhibited multiple muscle activations and a higher risk of ankle injury during sport-related activities.
- A systematic review by Witchalls et al. showed that ankle proprioception is associated with ankle injury.
- In a systematic review and meta-analysis Xhu et al. found that patients with chronic ankle instability had impaired motor skills and joint position perception compared with healthy subjects.
- Studies of chronic ankle instability have shown increased thresholds of mechanoreceptors and decreased proprioceptive acuity.
Individuals with chronic ankle instability develop cognitive impairment characterized by increased mechanoreceptors and decreased proprioceptive acuity. It is suggested that cognitive approaches should be included in the treatment of these disorders.
When an injury happens, it affects more than just muscles. Residual effects of injury include impaired proprioception with balanced loss of sensation of body position and joint position and changes in muscle spindle function. These changes in proprioception must be conscious ahosiesie denam:
- External manipulation
- Sensory integration therapies targeting proprioceptive input.
The basic principles when providing proprioception retraining are as follows:
- Start simple and slow
- Provide good instructions
- Do not threaten the patient
- Tasks should not cause more than minor pain
- Offer a reward
Intrinsics Foot Muscle Exercise
Intrinsics Foot Muscle Exercise
Short Foot Exercises
The elasticity of the foot muscles is important for the efficient biomechanical function of the musculoskeletal system of the lower extremity. Balance training to improve ankle proprioception and increase strength in the leg is referred to as short leg exercise (SFE). The ultimate value of. SFE is the development of a dynamic equilibrium position. The SFE training includes exercises that pull the first metatarsal head toward the calcaneus. There should be no twisting of the toes.  .
Benefits of including short foot exercises in the early stages of proprioceptive training after an ankle injury include:
- Stimulates neural circuits in the soles of the feet
- Improve posture and core stability
- Improvement in proprioception
According to Lee et al.  SFE training in patients with chronic ankle instability improves proprioception and homeostasis. They found that this training was more effective than standard proprioceptive motor training. The authors further conclude that SFE Starting earlier can promote a quicker return to daily life and physical activity. [twenty three]
Here are the guidelines from SFE:
- Weeks 1-4: Seated position with feet on stability trainer and hips, knees and ankles flexed 90º to stabilize body 
- Weeks 5-8: Stand 2 feet
- Weeks 5–9: single-leg stance
- SFE hold 5 seconds; 12 repetitions per session with 2 minutes rest between sets
- Performed three sets, 3 times a week
You can find out more about strengthening the intrinsic muscles of the foot here.
Sensory Targeted Ankle Rehabilitation Strategies
The Sensory Targeted Ankle Rehabilitation Strategy (STARS) consists of three interventions: joint mobilization reflexology and calf triceps stretch.  The treatment protocol consisted of six five-minute sessions of each component of STARS over a two-week period. Research shows that foot massage and joint mobility provide the best outcomes in terms of sensorimotor function in patients with chronic ankle instability.  Feldbrugge and colleagues  suggested that joint mobility and calf extension can improve ankle dorsiflexion and self-reported functional performance Chronic ankle instability. 
- Consists of a combination of petrissage and effleurage, covering the entire sole of the foot 
- Not specific to time spent or location of massage with either technique 
- One study found that reflexology prior to rehab exercises increased the effectiveness of the treatment by 30%
Triceps surae (calf muscles) stretching
The following techniques / devices can be used to stimulate cutaneous proprioceptive signals:
- Textured insoles:
- According to Corbin et al. textured insoles increase afferent information to the central nervous system to provide improved postural control in bilateral posture.
- Steinberg et al have found that the use of textured insoles in male dancers improved their dynamic balance posture indicating a beneficial effect on foot proprioception.
- Kinesio taping method:
- A study by Halseth et al. demonstrated that the Kinesio taping technique does not appear to enhance proprioception in healthy individuals.
- A systematic review by Wilson and Bialocerkowski provides recommendations for the use of a Kinesio taping technique in clinical practice to prevent hindfoot injuries due to its positive effects on proprioception muscle endurance and functional performance . . . .
- Training application in clinical practice: balance half ball wobble board multi-station training on 12 different BOSU Swiss balls:
- No improvement in ankle function / stability.
- It may be necessary to start later in the rehabilitation process
- It can freeze the patient because the skills required are too demanding.
- According to Donovan et al. the introduction of destabilizing devices during a 4-week rehabilitation program improved dorsiflexion during the stance phase of gait but had no effect on improving frontal plane motion.
Outside intervention is no better than rehabilitation as a stand-alone treatment. The final restoration plan should include the following:
- Integrated closed-chain dynamic regeneration processes
- Fixed and stable foot placement in a labeled position with verbal cues provided by a supervising therapist
- Visual information (mirrors) with external support.
Network meta-analysis by Tsikopoulos et al. concluded that external supports (taping bracing insoles with a combination of insoles and bracing) provided no benefit in improving active posture in individuals with ankle fractures. The authors suggest that using external support as a standalone option in rehabilitation for ankle instability does not make it optimal and that a combination of rehabilitation and external intervention may be more effective.
Tests for Proprioception
- The Balance Error Scoring System (BESS) description and testing protocol can be found here.
- Blecher R, Heinemann-Yerushalmi L, Assaraf E, Konstantin N, Chapman JR, Cope TC, Bewick GS, Banks RW, Zelzer E. New functions for the proprioceptive system in skeletal biology. Philos Trans R Soc Lond B Biol Sci. 2018 Sep 24;373(1759):20170327.
- Kahn J, Shwartz Y, Blitz E, Krief S, Sharir A, Breitel DA, Rattenbach R, Relaix F, Maire P, Rountree RB, Kingsley DM, Zelzer E. Muscle contraction is necessary to maintain joint progenitor cell fate. Dev Cell. 2009 May;16(5):734-43.
- Grigg PW. Peripheral Neural Mechanisms in Proprioception. Journal of Sport Rehabilitation,1994;3: 2-17.
- Simpson H. Understanding the ankle-Proprioception of the ankle Course. Plus2022
- Marzvanyan A, Alhawaj AF. Physiology, Sensory Receptors. [Updated 2021 Aug 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539861/
- Macefield VG.The roles of mechanoreceptors in muscle and skin in human proprioception. Current Opinion in Physiology, 2021; 21:48-56.
- Skinner HB, Barrack RL, Cook SD. Age-related decline in proprioception. Clin Orthop Relat Res. 1984 Apr;(184):208-11.
- Kaplan FS, Nixon JE, Reitz M, Rindfleish L, Tucker J. Age-related changes in proprioception and sensation of joint position. Acta Orthop Scand. 1985 Feb;56(1):72-4.
- Ribeiro F, Oliveira J. Aging effects on joint proprioception: the role of physical activity in proprioception preservation. Eur Rev Aging Phys, 2007; Act 4: 71–76.
- Panjabi MM. The stabilizing system of the spine. Part I. Function, dysfunction, adaptation, and enhancement. J Spinal Disord. 1992 Dec;5(4):383-9; discussion 397.
- McKeon PO, Hertel J, Bramble D, Davis I. The foot core system: a new paradigm for understanding intrinsic foot muscle function. Br J Sports Med. 2015 Mar;49(5):290
- Hiemstra LA, Lo IK, Fowler PJ. Effect of fatigue on knee proprioception: implications for dynamic stabilization. J Orthop Sports Phys Ther 2001;31:598–605.
- Cullen KE, Zobeiri OA. Proprioception and the predictive sensing of active self-motion. Current Opinion in Physiology 2021; 20: 29-38.
- Goodman R, Tremblay L. Using proprioception to control ongoing actions: the dominance of vision or altered proprioceptive weighing?. Exp Brain Res. 2018; 236: 1897–1910.
- Lephart SM, Pincivero DM, Giraido JL, Fu FH. The role of proprioception in the management and rehabilitation of athletic injuries. The American journal of sports medicine. 1997 Jan;25(1):130-7.
- Payne KA, Berg K, Latin RW. Ankle injuries and ankle strength, flexibility, and proprioception in college basketball players. Journal of Athletic Training.1997; 32(3): 221–225.
- Fu SN, Hui-Chan CWY. Are there any relationships among ankle proprioception acuity, pre-landing ankle muscle responses, and landing impact in a man? Neuroscience Letters. 2007; 417(2):123–127.
- Witchalls J, Blanch P, Waddington G, Adams R. Intrinsic functional deficits associated with increased risk of ankle injuries: a systematic review with meta-analysis. British Journal of Sports Medicine. 2012; 46(7): 515–523.
- Xue X, Ma T, Li Q, Song Y, Hua Y. Chronic ankle instability is associated with proprioception deficits: A systematic review and meta-analysis. J Sport Health Sci. 2021 Mar;10(2):182-191.
- Kwok SE, Bird L. Injury Consequences. Available from https://www.scape.sg/wp-content/uploads/2020/09/28-Sept_How-do-we-know-when-we-are-ready-to-return-to-dance-after-an-injury-1.pdf [last accessed 13.05.2022]
- Sulowska I, Mika A, Oleksy Ł, Stolarczyk A. The influence of plantar short foot muscle exercises on the lower extremity muscle strength and power in proximal segments of the kinematic chain in long-distance runners. BioMed research international. 2019 Jan 2;2019.
- Moon DC, Kim K, Lee SK. Immediate Effect of Short-foot Exercise on Dynamic Balance of Subjects with Excessively Pronated Feet. J Phys Ther Sci. 2014 Jan;26(1):117-9.
- Lee E, Cho J, Lee S. Short-Foot Exercise Promotes Quantitative Somatosensory Function in Ankle Instability: A Randomized Controlled Trial. Med Sci Monit. 2019 Jan 21;25:618-626.
- McKeon PO, Wikstrom EA. Sensory-Targeted Ankle Rehabilitation Strategies for Chronic Ankle Instability. Med Sci Sports Exerc. 2016 May;48(5):776-84.
- Feldbrugge CM, Pathoomvanh MM, Powden CJ, Hoch MC. Joint mobilization and static stretching for individuals with chronic ankle instability – A pilot study. J Bodyw Mov Ther. 2019 Jan;23(1):194-201.
- Motion Guidance. Lateral Ankle Sprain Mobilization with Movement. 2017. Available from: https://www.youtube.com/watch?v=oSQK6Z6i0nI [last accessed 14/5/2022]
- Massage Therapeutics. How to apply Effleurage and Petrissage massage techniques. 2021. Available from: https://www.youtube.com/watch?v=WkhPPr-MmSg[last accessed 14/5/2022]
- Core Elements Training. Introduction to Massage of the Foot from Prone position – Level 3 Sports Massage Techniques. Available from: https://www.youtube.com/watch?v=2TPVQO_7H3w [last accessed 9/11/2022]
- ReActive SORC. The Tricep Surae, Calf Muscle Stretch and Strengthen. 2020. Available from:https://www.youtube.com/watch?v=nCCkSUHgwGQ[last accessed 14/5/2022]
- Corbin DM, Hart JM, McKeon PO, Ingersoll CD, Hertel J. The effect of textured insoles on postural control in double and single-limb stance. J Sport Rehabil. 2007 Nov;16(4):363-72.
- Steinberg N, Waddington G, Adams R, Karin J, Tirosh O. Use of a Textured Insole to Improve the Association Between Postural Balance and Ankle Discrimination in Young Male and Female Dancers. Med Probl Perform Art. 2015 Dec;30(4):217-23.
- Halseth T, McChesney JW, Debeliso M, Vaughn R, Lien J. The effects of kinesio™ taping on proprioception at the ankle. J Sports Sci Med. 2004 Mar 1;3(1):1-7. PMID: 24497814; PMCID: PMC3896108.
- Wilson B, Bialocerkowski A. The Effects of Kinesiotape Applied to the Lateral Aspect of the Ankle: Relevance to Ankle Sprains–A Systematic Review. PLoS One. 2015 Jun 23;10(6):e0124214.
- Federici A, Zumbo F, Lucertini F, Marini CF. Proprioceptive training and sports performance. Journal of Human Sport and Exercise, 2020; 15(4proc): S1160-S1168.
- Donovan L, Hart JM, Saliba S, Park J, Feger MA, Herb CC, Hertel J. Effects of ankle destabilization devices and rehabilitation on gait biomechanics in chronic ankle instability patients: A randomized controlled trial. Phys Ther Sport. 2016 Sep;21:46-56.
- Tsikopoulos K, Sidiropoulos K, Kitridis D, Cain Atc SM, Metaxiotis D, Ali A. Do External Supports Improve Dynamic Balance in Patients with Chronic Ankle Instability? A Network Meta-analysis. Clin Orthop Relat Res. 2020 Feb;478(2):359-377.
- RCcedseminars. Balance Error Scoring System (BESS) Test. 2018. Available from:https://www.youtube.com/watch?v=vCLjgBxBcd0[last accessed 14/5/2022]
- MAT. Why you should be using the Star Excursion Balance Test (SEBT) with your patients. 2015. Available from:https://www.youtube.com/watch?v=zSGX7ZRXmx0[last accessed 14/5/2022]