Side Effects of Verbal Cueing and Interventions to Alter Gait Deviations

Original Editor - Stacy Schiurring based on the course by Damien Howell

Top Contributors - Stacy Schiurring, Kim Jackson, Jess Bell and Lucinda hampton

Introduction

Welcome to the last module for gait analysis and gait training. This module is entitled Side Effects of Verbal Cueing and Interventions to Alter Gait Deviations. I'm going to use this module to synthesise the previous 12 modules on gait analysis and gait training, where you see a gait deviation and we do something, you intervene using the mechanisms of motor learning and criteria for good verbal cueing of external focus of attention and paying attention to the sensory preference of your client or your patient. And then discussing being proactive in terms of identifying and recognising potential side effects of whatever intervention that we choose.

Definitions

Definitions:

A side effect is typically an undesirable or unintended consequence of an intervention.

A nocebo effect occurs when a patient's negative expectations of a treatment causes the treatment to have a more negative outcome than it otherwise would have.

Placebo

Evert Verhagen et al. in 2014 pointed out, when it comes to intervening with physical activity, exercise, and gait training, when we compare that to intervening with medicine, the adverse effects or the side effects or the unintended consequences, we tend to ignore them or don't pay attention to them.

The risk of adverse effects when prescribing rehabilitation interventions such as physical activity, exercise, or gait training are low but they are not nonexistent. Clinicians should be proactive in sharing potential side effects with patients as part of treatment informed consistent.

Clinical benefits of sharing potential side effects:

1. Increasing the level of engagement with patients
2. Can facilitate timely adjustments for chosen interventions
3. May itself induce the side effect or the unintended or adverse effects through the effect of what's called the nocebo effects. So if you tell the patient, I expect you to feel a soreness in this muscle, it increases likelihood that they're going to increase that soreness in their muscle. So we tend to often, inadvertently, tend to avoid sharing side effects because it may have a negative effect. So, clinicians' decision regarding what information to share regarding side effects can be overt or covert. If we, the clinician decide I'm not going to share these potential side effects because of the nocebo effects, we still need to have those, we still need to recognise them and have them in the back of our mind so that when it does happen, we're ready to deal with it and make adjustments. We need to recognise it.

The clinical reasoning process of a working hypothesis can be used to solve the problems of side effects or unintended consequences. For example, here's a working hypothesis. If the gait deviation of slow velocity is given to walk faster, the cue is, I want you to walk faster is provided, then the velocity will increase without changing their pain or their level of pain. That's a working hypothesis. If the verbal cue to walk faster is given, then the side effect will be an increased energy expenditure. Right? I think that's a good side effect. In most patients with painful musculoskeletal syndromes, they have a high body mass index. So the side effect of walking faster is they're going to get tired and expend energy. Recognising that is the process, the clinical reasoning process of side effects.

So the three common side effects of altering the gait that occur across most of them is increased energy expenditure, it can be physically taxing to walk and run in a new way. Increased cognitive demand, the brain must work harder to meet the task. Increased muscle fatigue and soreness for utilising muscles in a novel way.

Gait Deviations

So we presented 39 different gait deviations in previous modules, and there's a handout available and the references that include these 39 gait deviations for painful musculoskeletal syndromes and some neurologic gate deviations. And then there's a list of potential verbal cues or interventions and potential side effects. We're going to talk about three general side effects in this module. It is likely you'll see gait deviations that are not on that list of 39. Your patient population may be different. Your situation may be different, but you can use the process that we're presenting to develop your own system. My patient population in Virginia is a little bit different than yours, but use this process as a template to enhance your toolkit.

So the first of four gait deviations I'm going to discuss in this module is the gait deviation of too long a step or stride. And remember it's related to musculoskeletal pain syndromes of back pain, anterior hip pain, lateral knee pain, IT band syndrome, anterior knee pain, patellofemoral arthralgia, medial tibial stress syndrome, stress fractures, Achilles pain, plantar heel pain syndrome. So given that gait deviation, we need to come up with a verbal cue. We've talked about using an external focus or an internal focus, providing the patient with a choice, trying to give the cue based on the patient's sensory preference. So an internal focus of attention verbal cue that is visual for too long a step or stride would be, imagine or visualise walking on hot sand. That analogy would be, I gotta get off that sand quickly, I'm probably going to be taking a higher cadence and perhaps shorter steps. An auditory internal focus of a cue would be, visualise sneaking up on somebody because there's a correlation between a loud foot strike and too long a foot strike. A kinaesthetic or tactile internal focus of a cue would be just take shorter steps, more steps per minute. It's internal. And they need to feel that. As opposed to an external focus of cue, prompt, or feedback that's visual, you could use laser light targets to say, take shorter steps. An auditory external focus would be listen to the metronome of an appropriate cadence, cadence is related to step length. Kinaesthetic would be to use a wearable that measures cadence and provides vibratory input to the appropriate cadence affecting the step length.

So what's the side effect of altering the step length to make it shorter? This is where there's some good research to show that it affects energy expenditure. The least energy expenditure is what the patient automatically instinctually chooses. What we'd all choose. It's the path of least resistance. You take the preferred step length or stride length because it's the most economic. We're going to go in and say, I need you to take shorter steps. The effect is going to be acutely requiring an increased energy expenditure. The question is, is that permanent or temporary? There's some interesting paper just published by Eoin Doyle in 2022, looking at a systematic review of runners going through gait training to alter their step length and their cadence. And their conclusion was long term, the performance, to be able to run farther and or faster was not adversely affected by altering a person's step length. So that's a side effect. We can warn the patient. It's going to be tiring, but if you work through this, you'll do okay.

The next gait deviation I want to talk about is the gait deviation of a late heel off or delayed heel off, insufficient ankle plantarflexion and terminal stance phase. Remember the pain syndromes that are associated with that could be anterior hip pain, anterior knee pain, patellofemoral arthralgia, anterior ankle pain, Achilles pain when the Achilles is too long with the stretch weakness and plantar heel pain syndrome. So what are some verbal cues that we can use in that situation that are internal focus of attention, that are visual? You could describe to the patient, imagine you see yourself propelling up and forward. See that you're propelling forward and up. An auditory would be self-talk, walk with spring in your step, walk with spring in your step, hear it. Whereas a kinaesthetic internal focus would be feel your heel lift off the ground sooner. An external focus of attention that's visual is walk towards the mirror and watch the top of your head and to get it to go higher up and down. An auditory external focus of attention would be listen to the verbal cue from the therapist or coach that, yep you got it, no dampen it it's too much. Or you need more effort. That's external focus. And the kinaesthetic could be using elastic tape through the calf muscle, kinesio would be a bit of an external focus of attention trying to encourage ankle plantarflexion.

So what are the potential side effects of altering a person's delayed or late heel off? I wanna use this as an example for the side effect that's kind of generic across all interventions for explicit gait training, which is cognitive overload. Asking a person to think about it is going to challenge them mentally. There's too much information, too many tasks, and it adversely affects the motor learning process. It's going to happen. So how do we, what do we do when it happens? We can discontinue it, discontinue the intervention. We can continue and encourage the patient to work through it. We can switch from the whole to the part, where you do whole-part-whole, walk this way. Break it down into segments so that it's not what we're asking them to think about is not overloading them. Or we can modify the intervention, just like a physician would modify the medication dosage. Add a different medicine, take one away, switch the sensory preference of the verbal cue that we're providing to the patient.

The next gait deviation I want to talk about is the gait deviation of too much toe out, more than 15 to 20 degrees of the foot progression angle. And that's associated with the musculoskeletal pain syndromes of hip osteoarthritis, and it may be continuing after they have a normal hip as a habit. The same is true for knee osteoarthritis. This is a frequent gait deviation that's an automatic compensation for the knee pain contributing to the knee osteoarthritis, and it can continue once the knee is a good joint as a habit. It also is present with patellofemoral arthralgia, medial tibial stress syndrome, Achilles pain, plantar heel pain syndrome, pain on the ball of the foot, metatarsalgia, hallux limitus, or big toe osteoarthritis and bunions. So if you see something and you see they have 45 degrees of toe out when they're walking or running down the road, we're going to alter it with verbal cueing. An internal focus that is visual is, imagine and visualise your foot is the front tire on your car. Keep it pointing straight down the road. That's the image, the analogy. An auditory internal focus is listen to the verbal cue of the coach or the therapist, yep, you got it; no, dampen it, it's too much; or you've got to put more effort into it. A kinaesthetic cue would be push your heel outward or turn your toe inward and point it straight ahead. An external focus visual would be to put a marker on the ground, on the treadmill, on the road, a line. Line your foot up with it. It's external to the body. An auditory is say out loud, when you're walking, turn your foot inward, turn your foot inward. A kinaesthetic would be to tap the muscles on the front of the hip because it's likely they're doing it up at the hip. Use this muscle, turn it in. Or put it on their butt and say, you should feel some stretching in there as a verbal cue.

So there's a fair amount of literature that knee osteoarthritis, an automatic compensation is to toe out. And so we're going to say, I want you to toe in. Why do they toe out? Well, the work of Hunt and his colleagues have come up with a biomechanical explanation. In this illustration, we're looking at the schematic of a right leg from the front because you can see the orientation of the fibula is on that side. And in figure A, the foot is lined up straight ahead, less than 15 degrees of toe out. And then figure B the figure is toed out more than 15 degrees. The black vertical line is the ground reaction force, the dotted line is the distance from the ground reaction force to the knee joint axis. And that is a measure of what's called knee adduction moment or a varus moment or movement of the knee, which is highly associated with knee osteoarthritis. So anything we can do to decrease that knee adduction moment is going to decrease the knee pain if they have knee osteoarthritis. So the patient will automatically decrease that distance as in B, by toeing out. Now they have a new knee, where they don't need to do that, we're going to tell them to toe in.

So we're going to talk about side effects. So in this example, in this video, she's status post right total knee replacement. She's doing the dance step to nowhere with more than 15 degrees of toe out in the right leg. I tell her, point your toe straight ahead and do it this way. What's going to be the side effect of doing that? It's going to decrease knee adduction moment and that's fine, but the potential adverse effect when you toe in, you increase the knee flexion moment. Now, acute or early in the total joint replacement, they're going to have a weak quadriceps and they may not feel comfortable toeing in. And they may feel a little more pain in the knee when they toe in, as they're recovering from the total knee replacement. So you can be aware of that and if they say, you do the dance step to nowhere, point your foot straight ahead. And they say, doc, I'm getting more knee pain, or then you need to ask them, is it in the joint or is it in your thigh muscle? Is it a fatigue of the quadriceps? That's something I want you to work through. That's how you can begin to problem solve.

The last gait deviation I want to talk about is the common one of lateral pelvic drop, contralateral pelvic drop. The pain syndromes associated with that are back pain, hip labral problems, gluteal tendinopathy, piriformis syndrome, patellofemoral arthralgia, IT band syndrome, medial tibial stress, ankle pain, Achilles pain, and plantar heel pain syndrome. So what are the verbal cues that we can use that are internal focus of attention? A visual would be, imagine your pelvis is a bucket full of water, don't let that spill out. Keep it level. Auditory would be, imagine your pelvis is a hand bell, quiet the clang. That's an analogy and an image. Kinaesthetic internal, touch your hip muscle I want you to engage and use that muscle when you're doing the dance step to nowhere and when you walk this way. An external focus would be walk towards the mirror and watch your belt line and keep it more level. Or use a laser light on the contralateral hip and put a target in front of them. An auditory external focus would be listen to your foot strike and make it symmetric and smooth. Kinaesthetic would be a hip spica brace, a neoprene sleeve, a non-elastic strapping technique or elastic kinesio-strapping.

So what are the potential side effects of altering your lateral pelvic drop? This is where I want to use the example of increased muscle fatigue and soreness. You're going to expect them to get sore in their gluteal muscles. Now, if they come to you complaining of gluteal tendinopathy pain, the discomfort they're going to feel from the intervention is going to be in the same location that they came to you complaining of a symptom. So you need to have that discussion and talk about the nature of the pain. Is this the burning pain that keeps you awake at night? Or is this a good muscle soreness that you get from doing exercise and working through? So the hypothesis is if explicit alteration of gait deviation of too long a step, what are the muscles that are going to be a sore or fatigued? It's the thigh, maybe the calf muscles. Excuse me, that was for too long a step. If you take shorter steps, they're going to feel more stretch and more strained in the calf and thigh. Lateral pelvic drop is going to be the gluteal muscles. If they have prolonged heel contact or late heel off, they're going to feel soreness in the foot because now they're going to use the front of the foot and fatigue in the calf muscles, maybe the gluteal muscles, because there's a synergy between calf and glutes. And if they're excessive out-toeing and they're going to in-toe, they're going to feel a fatigue in the internal rotators of the hip and stretch in the lateral rotators of the hip.

Resources

Clinical Resources:

• find the two handouts from the lecture

Optional Additional Reading: