Physiotherapy and Magnesium Deficiency Part 2 - Case Examples

Last week, I created a post about the importance of magnesium as a public health crisis in Canada, with an overview of what magnesium is, along with functions, vulnerable populations, and consequences of deficiency.

Today, as promised, I've put together three recent case examples of real patients I've encountered in my clinical practice as an outpatient physiotherapist.

Case 1 - Glute Bridges

A wonderful woman had been referred for bilateral back, hip, and knee pain that had been going on for quite some time. In her assessment, all red flags were ruled out, and she had already undergone imaging that was unremarkable. I couldn't find a clear diagnosis, but I did identify grave muscle weakness in her core, low back, and lower extremities.

This woman reported that she sits 10 hours per day at work and is otherwise not very active. After consultation and assessment, I had prescribed a few exercises. She came back to me and reported that she cannot do glute bridges because they give her muscle spasms in her legs. My first response is to review the exercise with her and ensure her technique was optimal. We made a few modifications, reviewed the remainder of her exercises and followed up the next week. Sometimes cramping is purely a result of muscle weakness, so I thought I'd give it a bit more time.

"I still can't do the glute bridges. I can't do any of the exercises because they all give me cramps".

We proceeded to again review the bridge, the straight leg raise, the quad setting, the glute setting, and the clamshell. She couldn't get past 1 repetition without cramping.

After a little probing, I learned more about her diet, her hydration levels, and that she has also been getting cramping in her calves and feet during the night for many years.

The diet she reported to me contained no magnesium-rich foods - think pumpkin seeds, roasted peanuts, cacao, spinach and leafy greens, cashews, chia seeds, almonds, soy, oats. Her hydration was minimal, and when I asked her about magnesium, she said she's never considered it.

We discussed magnesium in its entirety, and with her consent, I wrote a note to her referring physician and encouraged her to speak with them about a supplement.

...two weeks later...

"My doctor gave me this magnesium and I started it last week and I haven't had a cramp since".

We progressed her exercises and her back and hip pain began to diminish.

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Case 2 - Tingling Feet

Rather recently, a woman was referred for what was said to be "sciatica" and "radiculopathy. Her primary symptoms were almost constant tingling in her feet. It wasn't painful, but it was bothersome enough for her to be thinking about it most of the day, and for it to keep her up at night.

She'd never had an injury to her feet, legs, or back that she knew of. She had imaging done before I had seen her, which was unremarkable (lumbar x-ray and MRI).

She had no symptoms of burning, tingling, or numbness in her back, glutes, thighs, or calves.

During my assessment, I couldn't find a single test to provoke or relieve her symptoms. I checked her back, her hips, her knees, ankles, feet, distal and proximal nerve tension, pulses, and more. Nothing would change her experience.

I had gone back to my subjective assessment.

"Please remind me, did this appear all of a sudden or was it gradual?"

"I can't remember exactly, but I think it started one day and wasn't so bad, but it kept getting worse and worse even though nothing I did was any different than before".

Since I couldn't find anything in her musculoskeletal, cardiovascular, or neurological history that could explain these symptoms, I thought I'd dig deeper into other aspects of her life.

We talked about exercise, and she was pretty active with exercise classes, yoga, walking, and gardening. Her strength was adequate when I tested her.

We then talked about diet, and then it all became clearer.

In the midst of our conversation, the cost of food came up. We chatted about how expensive food is becoming, and she told me that she used to "just love eating almonds with raisins" as a snack. She used to put almonds and pumpkin seeds in spinach salads with goat cheese and strawberries.

"Those days are long gone now. The cost of spinach is unearthly", she said to me.

It was in that moment when I realized she had drastically shifted her diet from one that is magnesium-rich to one that is deprived of it.

We created a diet log and found few, if any foods with high levels of magnesium.

I suggested that given my inability to provoke or relieve, or quite frankly change her symptoms in any way, it is difficult to determine a treatment plan at this time. Her strength was good, her range of motion was fine, her muscle length was great, likely thanks to all of her yoga classes, and there were no activity patterns that seemed maladaptive or suboptimal.

I suggested we follow up in a couple weeks to give me time to research and chat with colleagues in case I've missed anything, but I encouraged her to speak with her physician or pharmacist about the possibility of a magnesium deficiency in the meantime.

At our next follow-up, she informed me that she had a phone call with her Nurse Practitioner about it. She had recently gotten blood work done and everything was "normal", but her nurse had suggested a couple magnesium supplements "just to try", one of which she purchased the week prior.

She'd been taking it every day and reported to me that her symptoms were 80% better.

We followed up 3 weeks thereafter and she said her symptoms were gone.

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Case 3 - Weight Lifting Plateau

I was working with a young man who was generally active and was getting into more serious weight lifting.

He was generally healthy with nothing other than some slight knee pain when he first started lifting. He self-referred to physiotherapy because his progress was hitting plateau and he wondered if his technique was an issue, or if perhaps he had unidentified muscle imbalances. He wanted a more objective opinion.

His posture was excellent.

He had great activation of often-weak muscles including serratus anterior and posterior, rhomboids, and glute medius and minimus.

We reviewed most of his typical exercises, and he demonstrated excellent technique.

He had excellent core strength and pelvic control.

He was taking 2 rest days per week.

He was drinking 3+ liters of water each day.

He was supplementing with protein and eating lean meats, vegetables, and whole grains.

He was experiencing no pain anywhere in his body at this time.

What was the problem?

At his next session, I reviewed his subjective history again to make sure I didn't leave anything out. I double checked his technique for many exercises, in particular the ones where he felt his progress was suffering (barbell squats, deadlifts, goblet squats, rows, bench press).

I asked him to run through his entire week's exercise program with me.

At this time, he revealed to me something new: he normally does 10-20 minutes of intense cardio after each lifting session, but recently he started using his rest days as cardio days. He had told me they were rest days because he is resting from heavy lifting, but I thought he meant they were true rest days, free of structured exercise.

His cardio days consisted of 45-minute stair climber sessions. He had essentially added 90 minutes per week of intense activity.

He was supplementing with protein, but not electrolytes. He had increased his sweat secretion drastically, which means he has increased his depletion of magnesium and other electrolytes drastically. I had encouraged him to do the following:

a) take at least one true rest day per week to allow his muscles to replenish strength and energy

b) consult with his physician, nurse, or a pharmacist about electrolyte replacements.

At our next follow up, he reported that he had started an electrolyte replacement which contained 60mg of magnesium and had taken a full rest day that week, and over the next couple weeks, he noticed less fatigue during exercise.

At our 6 week follow up, he had noted substantial improvements in his weight capacity.

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These are just three of many examples I could provide involving the use of physiotherapy knowledge and expertise to minimize the burden of magnesium deficiency.

For these three individuals who were experiencing magnesium deficiency, the early detection may have prevented future heart, muscle, and bone conditions, falls and fractures, and may have avoided thousands of dollars in unnecessary medical costs.

Let us remain open-minded about the possibilities of our practice, and embrace education as a core component of our scope of practice beyond exercise and ergonomics.

Let us not forget the bigger picture and large scale impacts we are capable of creating, so long as we advocate for ourselves and our profession to bring us closer to the public health spotlight.