Walking with Diabetes: Is There a Hidden Culprit?
"New research uncovers the surprising truth about why people with diabetes may struggle with walking and increased metabolic costs, challenging common assumptions."
People living with diabetes often experience changes in their gait and increased metabolic cost, making walking more challenging. Researchers initially suspected that differences in the vertical displacement of the body's center of mass (CoM) might be a factor, contributing to the increased effort required for walking. The aim of this study was to investigate whether vertical CoM displacement, along with step length, could explain the higher metabolic cost of walking (CoW) commonly observed in people with diabetes.
The study involved thirty-one non-diabetic controls, twenty-two diabetic patients without peripheral neuropathy, and fourteen patients with moderate to severe Diabetic Peripheral Neuropathy (DPN). Participants underwent gait analysis using a motion analysis system and force plates while walking at matched speeds. Researchers then examined the vertical displacement of the CoM, seeking differences between the groups.
Surprisingly, the results indicated that vertical displacement of the CoM was not significantly different between the diabetes patients and the control group. Instead, the study pointed to other factors, such as shorter step lengths, increased cadence, and increased internal work, as potential explanations for the higher metabolic cost of walking in people with diabetes. This article explores the study's methods, findings, and implications for understanding the biomechanics of walking in individuals with diabetes.
Diabetes Basics and Risk
Diabetes is a chronic condition that affects how the body turns food into energy. It occurs when blood glucose is too high, often because the pancreas does not make enough insulin or the body does not respond properly to insulin. The CDC identifies three main types: type 1, type 2, and gestational diabetes. The American Diabetes Association emphasizes understanding risk and taking early action to help prevent type 2 diabetes.
Unmasking the True Culprits: Why Walking Feels Harder with Diabetes
The study revealed that while people with diabetes do exhibit biomechanical gait alterations compared to controls, the vertical displacement of the CoM wasn't the primary driver behind their increased metabolic cost of walking. People with diabetes often display reduced walking speed and higher stride variability. Researchers delved deeper to pinpoint the actual factors contributing to this phenomenon.
- Shorter Steps: Diabetic patients, particularly those with neuropathy, tend to take shorter steps.
- Increased Cadence: To maintain walking speed, individuals with diabetes often compensate for shorter steps by increasing their cadence (steps per minute).
- Internal Work: Shorter steps and increased cadence lead to increased internal work. The body must work harder to accelerate and decelerate the limbs with each step.
- Muscle Forces: Walking with more flexed joints, a common adaptation in people with diabetes, requires greater muscle forces.
Biomechanics and Walking
Recent research has examined walking mechanics and the effects of peripheral neuropathy on gait. A pilot study reports that people with diabetic peripheral neuropathy take shorter steps and increase cadence, requiring more steps to maintain the same walking speed. Separately, the human-robot carrying task study measured centre-of-mass oscillation at 23(6) mm, outside the previously reported 27–46 mm range for unconstrained walking at similar speeds of 0.6–0.7 m/s. These findings illustrate why step patterns and centre-of-mass movement are important measures in walking research.
Limits of the Centre-of-Mass Explanation
People with diabetes show biomechanical gait alterations compared with controls and have a higher metabolic cost of walking. However, the study titled “Vertical displacement of the centre of mass during walking in people with diabetes and diabetic neuropathy does not explain their higher metabolic cost of walking” reports that vertical centre-of-mass displacement does not explain this increased cost. This finding limits the claim that altered vertical movement alone is the hidden culprit behind the extra energy required for walking.
Key Takeaways: Rethinking How We Understand Walking in Diabetes
This research challenges the long-held assumption that vertical CoM displacement is a primary factor in the increased metabolic cost of walking for individuals with diabetes. While it's crucial to consider overall gait patterns, the study's insights underscore the importance of focusing on step length, cadence, and muscle activity as key contributors.
These findings have important implications for developing interventions and rehabilitation strategies. For example, focusing on improving step length and optimizing cadence could potentially reduce the energy expenditure associated with walking in people with diabetes. Future research should explore interventions that target these specific biomechanical factors.
Ultimately, a deeper understanding of the biomechanics of walking in diabetes can pave the way for more effective treatments and strategies to improve mobility and quality of life for those affected. This includes exercises to strengthen key muscle groups and interventions to improve joint flexibility.