Lower limb weakness can present in children and young people who are diagnosed with muscular dystrophy, multiple sclerosis, or cerebral palsy. Regardless of its etiology, lower limb weakness in adolescents can be improved through prudent and creative strength movements that any personal trainer can assist with.

As athletes and personal trainers, we are quite familiar with the sensation of weakness in our limbs. It typically follows an intense quadriceps workout, rendering one feeling as if his legs were made of Jell-O. Knowing that this will pass within 24 hours, it is not given a second thought. However, the sudden onset of such weakness in an otherwise healthy child can be both confusing and frightening for parents.

What is Lower Limb Weakness?

Weakness in the limbs and even polio-like paralysis are frequently the first signals parents observe in children with no underlying comorbidity. Recently, isolated cases of a disease known as acute flaccid myelitis, or AFM, have medical professionals concerned and a bit confounded. The Centers for Disease and Control consider it a rare but potentially serious condition that mainly hits children, affecting the general nervous system, specifically the spinal cord. Frighteningly, a child may be fine one day, and unable to walk the next.

Although not yet definitively proven, many research scientists believe the antagonist associated with AFM is the enterovirus EV-D68. 362 cases of AFM were reported to the CDC between 2014 and 2018. According to Dr. Kevin Messacar, an Infectious Disease specialist at Children’s Hospital Colorado, “We don’t yet have any effective treatment for the virus or for the condition. But we do know that over time, with rehabilitation therapies, many of the children can regain function.”

Responding to the Need

Recently an inquiry was sent to NFPT regarding just such an adolescent. The writer, a personal trainer, shared this:

 I have a young boy who has a situation that has been plaguing many young children lately and is acting similarly to polio. Weakening appears especially in the arms and legs and occurs out of the blue.

I have successfully trained clients with cerebral palsy and Parkinson’s as well as other infirmities. My question is: Can I slowly proceed in helping this boy of 11 years old with these same types of strengthening exercises, progressing as he gets stronger?

Realizing that this might not be an entirely isolated situation, we chose to address limb weakness in general for purpose of educating trainers and opening the door for an even more diverse clientele. For children who present with weakness in their extremities, strengthening exercises have proven beneficial for long-term functional gains, improved movement patterns, and optimal posture.

When limbs are lacking in strength (power), muscular endurance follows suit. With a dramatically lowered work capacity, the individual ends up expending a greater amount of energy simply to move.

Addressing and Improving Patterns of Movement

During the course of normal adolescent development, core strength builds through regular practice of active movements as well as those working against gravity. A child will practice small components of a movement pattern before using the pattern functionally.

To illustrate this point, we can think of a toddler who progresses from crawling to standing, and finally to walking and running. Children living with limb weakness, unfortunately, end up cultivating a limited repertoire of movement patterns. If we think of how an adult learns to strategize movement with an injured leg or a limp, we can begin to comprehend how a child with limb weakness develops compensatory movements.

While this may at first seem to functionally serve the child, his rapidly developing body ends up with decreased strength and endurance of his key muscle groups.

We can learn much about this realm of training by studying the approaches of professionals, both medical and therapeutic, in treating adolescents with cerebral palsy. Resistance training has shown great promise toward developing strength and skill in these children for over 50 years. Quantitatively, children with cerebral palsy exhibit significantly more weakness than their healthy peers; however, with proper training, their strength can approach near normal values.

Since young children learn best when they are having fun, strive for creative and playful limb strengthening when designing workout sessions. Exercises that mimic animal movement are a sure-fire way to begin.

Exercises to Implement

Duck walks build total leg strength and flexibility. Help the child stand with feet shoulder-width apart and squat down with his butt lower than his knees. Strive to maintain an upright torso and low butt as he takes small steps forward. After mastering this technique, prompt him to try stepping backward in the same position.

Frog jumps are another great animal exercise that encourages the development of leg strength and agility. Learning to jump and land correctly (with bent knees) helps to prevent injury.

It may be a good idea to demonstrate this exercise before having a client attempt it. Starting with feet shoulder-width apart, squat down, keeping the torso erect. Proceed to jump up, extending at the hips and knees as you propel yourself forward. Land with both feet flat and the knees bent, in preparation for the next jump.

Wall sits strengthen the hips, gluteals, and quadriceps, but from a young person’s perspective, they offer nothing in the way of creative entertainment. Set a time challenge for a young client; older clients may find a competition between you and him more fun and motivating. Playing a game of catch with a lightweight medicine ball while the client performs a wall sit can help distract him as he aims to complete the time challenge.

With back against a wall, walk feet out in front of body, positioning them shoulder-width apart. Slide down the wall until thighs are parallel to the ground. Make sure knees are aligned over the toes and hold.

Strengthening the calf muscles by working from tiptoes can help a child cultivate balance and agility, key components that compliment leg strength.

Mark out a straight linear path on the gym floor with masking tape. Instruct the client to rise up on tiptoes walk along the line without stepping outside or dropping down to the soles of the feet. Once this level has been successfully accomplished, try moving on to shapes or curvy patterns.

Compound Movements

There are several simple functional movements and activities that are not only creative but can be used to strengthen more than one area of a client’s limb weakness. Below is a list that includes movements commonly performed throughout a typical day.  Some of the movements are added for the sake of keeping the workout fun and interesting.

  • Playing catch with a medicine ball, moving the location and level from which the ball is thrown
  • Rolling or crawling up and down incline planks
  • Kicking backward in an attempt to knock over objects
  • Climbing activities on stairs
  • Backward walking through an obstacle course
  • Karate kicking at a bolster
  • Sidestepping on a balance beam

If you happen to be working with a group of young people, all of whom have varying degrees of the same limb weakness, plan relay races while holding a balloon or small ball between the legs.

Start With The End In Mind

Whether you are a personal trainer or a parent, helping children with limb weakness cultivate body strength can be accomplished in a safe manner. It is important to keep in mind that strength- training exercises should never be performed with a goal of building bulky muscles.

The focus should remain on technique and having fun while attempting to elevate endurance and work capacity. Enabling a young person to move more comfortably through activities (and play) encountered daily can have a tremendously positive effect on his overall outlook while helping him establish successful and stronger movement patterns for his future growth and development.

How have you successfully trained special populations of young personal training clients with limb weakness?

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Cathleen Kronemer

Cathleen Kronemer is an NFPT CEC writer and a member of the NFPT Certification Council Board. Cathleen is an AFAA-Certified Group Exercise Instructor, NSCA-Certified Personal Trainer, ACE-Certified Health Coach, former competitive bodybuilder and freelance writer. She is employed at the Jewish Community Center in St. Louis, MO. Cathleen has been involved in the fitness industry for over three decades. Feel free to contact her at trainhard@kronemer.com. She welcomes your feedback and your comments!