Why do children experience leg pain?

Children with Ehlers Danlos (hypermobility type) may partially dislocate the hip or knee joints. This damages the joint structures, with inflammation and swelling. Repeated episodes of subluxation lead to further damage and pain.  Children with Ehlers Danlos should be under the care of a physical therapist with special knowledge of joint hypermobility who will provide advice on how to deal with subluxations, protect the joints and how to use exercise to improve strength. 

Children presenting with generalized or benign joint hypermobility (GJH) may have varying degrees of hypermobility, often associated with tightness in some muscles and their associated fascial structures.  The tight muscles lead to abnormal stresses on joints that are already less stable than usual.  

In many activities good muscle action is also needed to protect joints. In GJH the muscles are often weak and do not adequately provide this extra protection. 

In addition a child with GJH may also be poorly coordinated with poor balance which leads to trips and falls, exposing the child's joint to further injury. 

So what you have in GJH is are joints that are less stable than usual, exposed to abnormal stresses due to muscle tightness and without adequate muscle strength to provide extra protection needed when walking, running and jumping.  This combination leads to pain after exercise or at night. 

More about the nature and cause of pain in EDS and JHS 

More about knee pain

Knee pain in children with GJH is may be  caused by one or more factors:

Looseness of the knee ligaments:   which  allows the knee to bend backwards more than usual. The child stands with the knees in hyperextension which puts strain on the knee ligaments. 

Weakness of the leg muscles: the leg muscles work to protect the joints from the stresses that normally occur when going up and down stairs, walking, jumping and running.  Children with hypermobility often have weak muscles which do no provide the support needed by the joints.  This strength is particularly important when walking, running and jumping. 

Tightness in the muscles and associated fascial structures that cross from the lower back over the side of the hips and knees. This includes the hamstring muscles and the fascia lata (also called the ilio tibial band). 

Children with tightness in the hamstring muscles cannot touch their ankles when sitting with their knees straight.  Often the child cannot reach much further than the knees.

 Children with tight iliotibial band often stand with their feet wide apart and turned out. Standing with the feet closer together is uncomfortable. 

The tightness in the iliotibial band tends to turn the foot out at the knee.  This twist at the knee puts a strain on the knee.  The child may walk or run with the knee turned slightly outwards. Usually the calf muscles are also weak. 

When the child stands with the knee caps  facing straight forwards the feet are turned out more than usual. 

Night pain during growth spurts

Night pain often occurs during periods of rapid growth.  Bone growth happens mainly at night and in spurts with increases of millimeters in a single night. As the bones grow the muscles, ligaments and tendons must  lengthen to adapt to the new bone length and this happens more slowly than the increase in the length of the bones and can lead to strain on the joints. 

What can be done for night pain?

1  Start a stretching and strengthening program  to deal with underlying tightness and weakness which will reduce joint strain from daily activities.
2  It is usually safe to give your child a a dose of paracetemol before going to sleep over a period of a few weeks during a growth spurt, but be sure to check this out with  your family physician..
3 Some children find some gentle stretching before bedtime is helpful. 

Gentle stretches before going to sleep

A one leg stretch

I find this stretch comfortable, even pleasant for the child. It should not cause any pain.

Let your child lie on a firm surface – the bed or on a mat on the floor.
With your child’s leg still flat on the surface hold one  foot with both hands – one hand under the heel and one over the bridge of the foot. 

Now gently pull on the foot as if you are trying to lengthen the leg and hold this gentle tension for about 20s. The pull should be gentle and comfortable. You should feel a sense of the leg giving and easing. 

If the pull is too hard you will not get this sense of easing and lengthening. Always pull less rather than more. 

A two leg stretch 

With your child still lying flat on the bed, sit facing the feet and rest your forearms on the bed. Cup your palms around and grasp the back of your child's heels.  

Now gently pull on the heels as if you were trying to lengthen the leg. Imagine the legs are two elastic bands and you are trying to stretch the bands just a little. 

NB In this picture you see me holding only one leg. This is because my left arm was in a cast and I could not position it correctly. The right hand shows thr correct  grip.

SfA Strength Training for Painful Legs  

• 5 graded exercises, 15 minutes a day for 4 weeks 
• Start slowly, increase load systematically and be dedicated  Read more

​Research has shown that a program of exercises to strengthen the leg muscles along with careful stretching of tight muscles will reduce pain significantly.  Your best option is to consult a physical therapist who has a good knowledge of joint hypermobility and can do a full evaluation and provide a program of exercises for your child.  

But as this option is not always immediately available, there are things that you as a parent can do the help your child. Exercises needed to be selected carefully so as not to cause pain and progressed over time to increase strength and flexibility.

Benefits of a strength training program

• Muscles that are stronger also tire less quickly, so that the child can tolerate more exercise before experiencing the discomfort that goes with having very tired muscle. 
• A strength training program that uses movement patterns similar to those used in everyday activities such as walking, running, and stair climbing has the added benefit of training coordination and strengthening the ligaments and well improving proprioceptive feedback. 
• Engaging in an exercise program that is challenging and requires effort increases the child's self confidence and willingness to keep going

Importance of training children to tolerate effort 

Children with joint hypermobility and a cautious nature will often not like the sensations that arise from effortful physical activity: the discomfort in the muscles, the fast beating heart and rapid breathing. 

Cautious children need to learn to distinguish between sensations of effort ie discomfort in muscles and the pain that arises from injury. Discomfort from strenuous exercise is GOOD. It means that the muscles are working hard and getting stronger. It is not a sign of injury. If a child is weak and unfit, even mildly strenuous activity will lead to a measure of discomfort and avoidance, promoting a vicious downwards spiral. 

An exercise program that starts slowly and progressive increase the load will increase strength and coordination without provoking too much muscle discomfort. Slowly but surely the child will get used to the sensations of effort and start to welcome them as a sign of hard work leading the better strength and function. 

Very important note: please consult your child's doctor or physical therapist before embarking on an exercise program. This is particularly important if your child has very bad and regular night pain, acute and persistent muscle pain or joint swelling and inflammation. 

More about the nature, cause and prevention of chronic pain in EDS and JHS 

Children with EDS and JHs are more likely than other children to develop chronic pain.  Repeated injury sensitizes the injured tissue (muscles and joints). If  full range of movement  and good muscle strength, coordination and balance are not restored after an injury the joint capsule, ligaments and muscles may continue to be a source of pain, with fear of movement and pain leading to reduced activity levels which in turn leads to sensitisation in the pain pathways.  What seems to happen is that the pain receptors in the joint  become oversensitive and start to respond in an abnormal fashion and this in turn leads to over activity in the sensory areas of the brain so that the link between injury and pain breaks down.  Read more