Beyond the Eye Test: The Tech Revolutionizing Gait Analysis in Osteoporosis

Beyond the Eye Test: The Tech Revolutionizing Gait Analysis in Osteoporosis

Last Updated: July 27, 2025

Introduction: A New Look at Walking

For years, assessing mobility in older adults, especially those with osteoporosis, often relied on subjective observation—a clinician’s trained eye watching a patient walk. But how fast is “slow”? What defines an “unsteady” gait in measurable terms? A 2019 PhD thesis from Ziauddin University explores the critical “paradigm shift” from subjective guesswork to precise, objective measurement in physical therapy. This research highlights how advanced wearable technology provides a far more accurate picture of gait, balance, and fall risk. This article delves into the specific tools and methods used in the study, explaining how modern technology is changing our understanding of gait analysis in osteoporosis.

The Problem with Subjective Measurement

The thesis begins by acknowledging the limitations of traditional methods. While interviews, activity diaries, and questionnaires are useful, they have drawbacks.

According to the research, “self-reporting methods often overestimate the activity volume due to recall bias or the presence of social desirability bias.” For instance, a patient might not accurately remember how much they walked, or they might unconsciously report more activity than they actually performed. Even a simple stopwatch and measuring tape, used for decades to calculate walking speed, have documented limitations, especially when measuring cadence (steps per minute).

This lack of precision is a major issue when managing osteoporosis, where an accurate assessment of gait and balance is vital for preventing life-altering falls. A decline in gait stability is a key predictor of fall risk, but to measure it accurately, we need objective data.

The Paradigm Shift: From Subjective to Objective Gait Analysis in Osteoporosis

The core of this research was its move towards highly accurate, objective tools. The study emphasizes that “with the advent of modern technology accuracy became the primary concern, so the investigators became keen to consider more valid and reliable tools during the analysis of gait.”

This shift is crucial for several reasons:

• Accuracy: Objective tools eliminate the guesswork and biases of self-reporting.
• Quantification: They provide hard data on key gait parameters.
• Early Detection: Precise measurements can detect subtle declines in stability long before they become obvious, allowing for earlier intervention.

The study employed several objective measurement tools, with the activPAL accelerometer being central to its innovative approach.

Spotlight on the Technology: The activPAL Accelerometer

The thesis champions the use of a research-grade, thigh-worn accelerometer called the activPAL. Unlike consumer fitness trackers, this device is specifically designed for clinical and research settings.

• What it is: The activPAL is a small (53x35x7 mm) device that is attached to the thigh. It uses a tri-axial accelerometer to measure the thigh’s position and movement.
• What it measures: Based on thigh orientation, its proprietary algorithms can accurately identify and quantify time spent sitting, standing, lying down, and stepping. This allows for precise measurement of Temporal-Spatial Parameters (TSPs) of gait.
• Key Gait Parameters Measured:
  • Gait Velocity: The speed at which a person walks (meters/second), calculated during a 10-meter walk test.
  • Cadence: The number of steps taken per minute.
  • Gait Stability Ratio (GSR): A crucial but less-known metric for assessing fall risk.

The study highlights that “quantifying the TSPs of gait… is found to be a better indicator of gait when compared with other… like actigraph and wrist worn accelerometers.” This is because placing the sensor on the thigh provides a much more accurate picture of posture and locomotion than a device worn on the wrist, which can record false movements from simple hand gestures.

Gait Stability Ratio (GSR): A Key Metric for Fall Risk

One of the most important metrics discussed in the research is the Gait Stability Ratio (GSR). This is a powerful indicator of balance deficits during walking.

As the thesis explains, “Gait Stability Ratio (GSR) is the reciprocal of cadence (steps/second) and gait velocity (meter/second)… It provides an indication of walking stability per unit of distance in a gait cycle.”

• What it means: A higher GSR indicates that a person is taking more steps to cover a shorter distance, spending more time in the double-limb support phase. This is often a subconscious strategy to increase stability but signals an underlying balance problem.
• Why it’s important: The study notes that a declining GSR is linked to an increased risk of falls among the elderly. By using the activPAL to precisely measure velocity and cadence, the researchers could calculate the GSR and track how it changed in response to exercise. This objective measurement is far more insightful than simply observing if someone “looks” unsteady.

Combining Tech with a Trusted Clinical Test: The TUG

The research didn’t rely on technology alone. It combined the data from the activPAL with a widely accepted clinical assessment: the Timed Up and Go (TUG) Test.

The TUG test measures dynamic balance and mobility by timing how long it takes a person to:

1. Stand up from a chair.
2. Walk 3 meters (10 feet).
3. Turn around.
4. Walk back to the chair.
5. Sit down again.

A score of 12 seconds or more is generally considered to indicate a high risk of falling. In this study, the activPAL was used to record the time simultaneously with the stopwatch, providing a confirmatory data point to “avoid observation bias.” This dual-method approach strengthened the validity of the findings, ensuring the data was both clinically relevant and technologically precise.

Conclusion: The Future of Osteoporosis Management is Data-Driven

This PhD study powerfully demonstrates that the future of effective gait analysis in osteoporosis lies in the integration of objective, wearable technology. Tools like the activPAL accelerometer move the assessment of fall risk from a subjective art to a data-driven science. By accurately measuring critical parameters like gait velocity, cadence, and the Gait Stability Ratio, clinicians can better understand a patient’s functional mobility, design more effective exercise interventions, and ultimately provide a higher standard of care to prevent falls and improve the quality of life for individuals with osteoporosis.

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Author Bio

Dr. Amna Aamir Khan holds a Doctor of Philosophy (PhD) in Physical Therapy from the College of Rehabilitation Sciences at Ziauddin University. Her research focuses on the effects of targeted exercise interventions on functional parameters in clinical populations.

Source & Citations

Thesis Title: EFFECTS OF OSTEOANABOLIC EXERCISES ON GAIT, BALANCE AND FEAR OF FALL AMONG OSTEOPOROTIC FEMALES
Researcher: Amna Aamir Khan (DPT, MSc)
Guide (Supervisor): Prof. Dr. Pirzada Qasim Raza Siddiqui
University: Ziauddin University, Karachi, Pakistan
Year of Compilation: 2019
Excerpt Page Numbers: 1, 16-19, 32, 34-35, 40-41, 69-71, 88, 107-111, 134

Disclaimer

“Disclaimer: Some sentences have been lightly edited for SEO and readability. For the full, original research, please refer to the complete thesis PDF linked in the section above.”

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Have you ever used a wearable device to track your health or fitness? How do you think this kind of technology could change physical therapy for the better? Let us know in the comments!