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

Verhagen et al. discuss the use of physical activity as a medicine to help decrease the burden of chronic and lifestyle-related diseases on the general public. While the benefits of physical activity are well known and shared with patients, the unwanted side effects or unintended consequences are often ignored or neglected as part of patient education.

Horvath et al. performed a systematic literature review and found that the nocebo effect can influence an individual's motor performance and can be evoked by negative verbal cues. In certain circumstances, the nocebo effect can be more robust than the placebo effect.

"Placebo and nocebo responses have been shown to play an important role in many health and performance-related areas of life. These can be induced by evoking positive or negative expectations, most often by providing positive or negative information about the effect of an inert or a real treatment.  In the medical context, the placebo response primarily refers to the reduction of subjective somatic symptoms, anxiety, depression, and pain, but it can result in objective clinical improvement too. The nocebo response has the opposite effects, which can lead to considerable suffering, non-adherence, and increased drop-out in clinical settings and trials, and may also result in fall incidents, breathing restrictions and impaired mobilization. Beyond medical settings, the placebo and nocebo phenomena can impact the physiological, behavioral affective, and cognitive functioning of healthy individuals, too." - Horath A et al 2021

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

"The nocebo effect can be provoked through verbal suggestion when patients are told by clinicians that there is a possibility of the development of adverse side effects. Verbal suggestion can condition patients to think or behave in a particular manner based on what the suggestions lead them to believe. If a patient observes another person in pain as a result of a certain stimulus, the patient is more likely to describe similar amounts of pain when they experience the same stimulus. Because they observed the other person’s reaction, it caused them to develop certain expectations as to how they may react." -Integrative Pain Science Institute

Side Effects of Altering a Gait Deviation

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 treatment cause the treatment to have a more negative outcome than it otherwise would have.

A placebo effect is the tendency of a medication or treatment, even an inert or ineffective one, to exhibit results simply because the recipient believes that it will work.

Possible clinical outcomes 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 unintended or adverse effects through the nocebo effects

A rehabilitation professional can use clinical reasoning to create a working hypothesis to try to improve the unintended consequences of therapeutic interventions.

The three common side effects of altering a gait deviation:

1. Increased energy expenditure; it can be physically taxing to walk and run in a new way
2. Increased cognitive demand; the brain must work harder to perform the task
3. Increased muscle fatigue and soreness for utilising muscles in a novel way

Gait Deviation Clinical Examples

Gait deviation	Related musculoskeletal pain syndromes	Sensory System	Internal focus of attention: Cue, Prompt, Feedback	External focus of attention: Cue, Prompt, Feedback	Potential side effects
Too long a step or stride length	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	Visual	Imagine/visualise walking on hot sand	Use laser light target for shorter steps	Making step length shorter could result in increased energy expenditure
		Auditory	"Walk like you are sneaking up on someone"	Listen to metronome beat at appropriate cadence beats/minute
		Kinaesthetic Tactile	Take shorter steps more steps/minute	Wearable device with vibratory feedback at appropriate cadence
Late/delayed heel off	Anterior hip pain Anterior knee pain Patellofemoral arthralgia Anterior ankle pain Achilles pain (due to stretch weakness) Plantar heel pain syndrome	Visual	Imagine/see yourself propel up and forwards	Walk towards a mirror and watch the top of your head, laser light target	Cognitive overload
		Auditory	“Spring in your step”	Listen to verbal cues provided: “yes”; “dampen it”; “need more effort”
		Kinaesthetic Tactile	Feel the heel lift off the ground sooner	Use of elastic tape
Too much toe out (more than 15 to 20 degrees of foot progression angle)	Hip osteoarthritis (OA) Knee OA Can continue after a total joint replacement Patellofemoral arthralgia Medial tibial stress syndrome Achilles pain Plantar heel pain syndrome Pain on the ball of the foot Metatarsalgia Hallux limitus Great toe OA Bunions	Visual	Visualise your foot as a front car tyre, keep it straight down the road	Align foot with tape or a line on the ground	Potential adverse effect with intentional increase of toe-in is a decreased knee adduction moment and an increased knee flexion moment Patients status post-total knee replacements with weak quadriceps may experience knee pain
		Auditory	Listen to verbal cues provided: “yes”; “dampen it”; “need more effort”	Say out loud "turn foot inward"
		Kinaesthetic Tactile	Push heel outward or turn toe inward	Touch or tap the muscles on the front of the hip, "use this muscle"
Lateral pelvic drop, contralateral pelvic drop	Back pain Hip labral problems Gluteal tendinopathy Piriformis syndrome Patellofemoral arthralgia IT band syndrome Medial tibial stress Ankle pain Achilles pain Plantar heel pain syndrome	Visual	Imagine the pelvis is a bucket of water, don’t let the water spill out	Walk towards the mirror, watch your belt and keep it level Laser light target	Muscle fatigue and soreness
		Auditory	"Imagine your pelvis is a bell, quiet the clang of the bell"	Listen for foot strike. Make the sound symmetrical and rhythmic
		Kinaesthetic Tactile	Touch hand to the gluteal muscles, "engage this muscle"	Hip spica brace Neoprene sleeve Nonelastic or elastic strapping of hip

Side Effects Special Topics

The "cognitive load theory, proposes that the development of training and instructional methods must take into account the limitations of cognitive capacities, particularly working memory, and that individuals learn most effectively when they allocate an optimal amount of cognitive resources." -Curtin A et al 2019

Cognitive overload can occur when a person is being challenged mentally by the therapeutic interventions. They are processing too much information or too many tasks, and it adversely affects their motor learning. The rehabilitation professional can modify this overload by (1) discontinuing the intervention, (2) continuing the intervention and encouraging the patient through the task, (3) modifying the task from the whole into smaller steps or parts, or (4) modifying the intervention by switching the sensory preference of the verbal cue being provided to the patient.

Increased muscle fatigue and soreness is an expected side effect of exercise. However, it is important to have a discussion and talk about the nature of the pain with each patient to ensure this new pain is not a warning sign of additional injury.

Examples of predicting which muscles will experience soreness and / or fatigue in response to the explicit alteration of gait:

Gait deviation alteration	Potential sources of muscle fatigue and / or soreness
Too long a step or stride to shorter steps	Thigh and / or calf muscles
Lateral pelvic tilt to a more stable pelvis / hip	Gluteal muscles
Prolonged heel contact to the appropriate heel off timing	Soreness in foot and or calf muscles, engagement of gluteal muscles
Excessive toe-out to appropriate foot progression angle	Stretching sensation of muscles around the hip, fatigue in muscles around the hip

Resources

Optional Video:

This optional video discusses the nocebo versus placebo effect, and provides clinical examples of the nocebo effect.

Optional Additional Reading:

• Horváth Á, Köteles F, Szabo A. Nocebo effects on motor performance: A systematic literature review. Scandinavian journal of psychology. 2021 Oct;62(5):665-74.