Did you know that the ankle is the most frequently injured joint, both in athletics and in daily life?
Ankle sprains are the most common athletic injury, and 70–85% of these are inversion-type sprains.
It has been reported that 10–30% of people with acute inversion-type sprains develop chronic mechanical instabilities as well as functional deficits, and approximately 80% of ankle sprains recur. According to the UK National Health Service (NHS), ankle sprain injuries account for around 1–1.5 million visits to accident and emergency (A&E) departments in the UK each year; and it is estimated that every day over 27,000 people in the USA sprain an ankle.
The ankle joint, showing the lateral ligaments
Stability Compensatory Mechanisms
Ongoing recurrent ankle sprains will, over time, lead to chronic ankle instability issues that will then cause kinetic chain dysfunctions. These abnormalities will have a knock-on effect on the homeostasis of the whole body, as the proprioceptive neural senses will now be reduced, and the stability compensatory mechanisms will be altered.
The ankle is a very complex joint comprising the talus, tibia, and fibula bones. The lateral ligaments of the ankle are the most susceptible to injury, and it is estimated that at heel-strike, up to five times the body’s weight is loaded onto this joint. The anterior talofibular ligament (ATFL) is generally the most commonly injured, followed by the calcaneofibular ligament (CFL).
Friel et al., in 2006, conducted a study about ipsilateral hip abductor weakness after an inversion ankle sprain; their results showed that hip abduction and plantar flexion were significantly weaker on the involved side. They concluded that unilateral ankle sprains led to weaker hip abduction (Gmed), and suggested exercises to strengthen the hip abductors when developing rehabilitation protocols for ankle inversion sprains.
The influence of a previous ankle sprain in relation to the firing order and timing of the posterior trunk and leg muscles during the hip extension firing test was investigated by Bullock-Saxton et al. in 1994. Those authors found a significant difference in the onset of the Gmax activity (delayed onset) in the group with previous ankle sprains compared with the control group.
GMed - Common Trigger Point sites. Trigger Points make the host muscle shorter and weaker and need to be considered when dealing with ankle sprains.
Dynamic Postural Control
In 2010 Leavey et al. reported the results of a study of the comparative effects of balance and strength programs, and a combination of the two, on dynamic postural control. The authors proposed using two types of strategies for maintaining dynamic postural control, specifically a hip strategy and an ankle strategy. For the ankle strategy they suggested utilizing the peroneal muscles to maintain balance, while for the hip strategy the Gmed muscle was recommended for correcting balance and posture. They point out that an individual does not usually strengthen the Gmed muscle when attempting to increase dynamic postural control following a lateral ankle sprain.
In most rehabilitation protocols for an inversion sprain, ankle strength training and proprioception training are typically encouraged, as these are used to regain losses in balance that may have occurred. It was also suggested that the weakened Gmed may cause defective dynamic postural control to worsen, leading to the biomechanics of the entire lower extremity becoming altered; this in turn potentially results in faulty movements, making individuals prone to future ankle injuries.
Finally, it's also worth noting that Schmitz et al., in 2002, demonstrated through an EMG study that there was an increase in Gmed activity during sudden ankle inversion in healthy subjects as well as in those with functionally unstable ankles.
This trigger point therapy blog is intended to be used for information purposes only and is not intended to be used for medical diagnosis or treatment or to substitute for a medical diagnosis and/or treatment rendered or prescribed by a physician or competent healthcare professional. This information is designed as educational material, but should not be taken as a recommendation for treatment of any particular person or patient. Always consult your physician if you think you need treatment or if you feel unwell.
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