Lack of ankle dorsiflexion often presents as altered gait with early heel lift (bouncy gait) or sometimes a gait type with total lack of heel strike. The most common cause of reduced dorsiflexion is ankle equinus from tightness or shortening of the gastrocnemius/soleus muscle group (triceps surae). This can cause premature activity of ankle plantarflexors.

The accurate measurement of available ankle range of motion is an important part of clinical decision making when considering treatment for any number of lower limb musculoskeletal conditions, including children who are toe walking, children with Charcot Marie Tooth, cerebral palsy or even calcaneal apophysitis. There have been a number of methods mentioned within the literature on measurement, including weight-bearing and non-weight bearing techniques [1, 2].

Non-weightbearing ankle joint range of motion normative reference values in children have been published with knee in flexion (soleus) and knee extension (gastrocnemius) [2]. Ankle dorsiflexion changes as children get older. Large variations in normative values have been reported in studies with ankle dorsiflexion measurements ranging from 9 degrees to 28 degrees with the knee extended. The reported differences may be due to the way the child has laid or the force applied to provide the stretch [2]. Bennell’s study demonstrated excellent inter and intra observer reliability of the weight bearing lunge test with older children standing to measure the amount of available ankle range of motion [3]. This test has been used in children as young as two years old [4}.

There are a number of tools used to assist clinicians in measurement of ankle joint range of motion, with the use of digital inclinometers and angle finders being commonly used in clinical practice. With smart phone technology, there are increasing numbers of apps being introduced to assist in assessment. The Tiltmeter app on the iPhone has been shown to be reliable to measure ankle range of motion [5].

References:

1. Evans, A.M., K. Rome, and L. Peet, The foot posture index, ankle lunge test, Beighton scale and the lower limb assessment score in healthy children: a reliability study. J Foot Ankle Res, 2012. 5(1): p. 1.

2. Mudge, A.J., et al., Normative reference values for lower limb joint range, bone torsion, and alignment in children aged 4-16 years. J Pediatr Orthop B, 2014. 23(1): p. 15-25.

3. Bennell, K.L., et al., Intra-rater and inter-rater reliability of a weight-bearing lunge measure of ankle dorsiflexion. Aust J Physiother, 1998. 44(3): p. 175-180.

4. Williams, C.M., A.J. Caserta, and T.P. Haines, The TiltMeter app is a novel and accurate measurement tool for the weight bearing lunge test. J Sci Med Sport, 2013. 16(5): p. 392-5.

5. Rose, K. J., Burns, J., North, K. N., Factors associated with foot and ankle strength in healthy preschool-age children and age-matched cases of Charcot-Marie-Tooth disease type 1A, J Child Neuro, 2010, 25(4): p.463-8