Measuring the Motor Aspect of Cancer-Related Fatigue using a Handheld Dynamometer

Summary

Simple and accessible methods were developed to measure the motor aspect of cancer-related fatigue objectively and quantitatively. We describe, in detail, ways to administer the physical fatigue test using a simple handgrip device as well as methods to calculate fatigue indices.

Abstract

Cancer-related fatigue (CRF) is commonly reported by patients both during and after receiving treatment for cancer. Current CRF diagnoses rely on self-report questionnaires which are subject to report and recall biases. Objective measurements using a handheld dynamometer, or handgrip device, have been shown in recent studies to correlate significantly with subjective self-reported fatigue scores. However, variations of both the handgrip fatigue test and fatigue index calculations exist in the literature. The lack of standardized methods limits the utilization of the handgrip fatigue test in the clinical and research settings. In this study, we provide detailed methods for administering the physical fatigue test and calculating the fatigue index. These methods should supplement existing self-reported fatigue questionnaires and help clinicians assess fatigue symptom severity in an objective and quantitative manner.

Introduction

Cancer-related fatigue (CRF) is an prevalent and debilitating symptom that is reported by up to 80% of cancer patients¹. The National Comprehensive Cancer Network (NCCN) defines CRF as a persistent sense of physical, emotional, and cognitive exhaustion¹. The main differentiating characteristics of CRF are the disproportionality to recent activity and the inability of CRF to be relieved by rest¹. As a result, CRF severely impacts patients' participation in daily activities and their health-related quality of life¹.

The current assessment of CR....

Protocol

The current study (NCT00852111) was approved by the Institutional Review Board (IRB) of the National Institutes of Health (NIH). Participants enrolled in this study were 18 years of age or older, diagnosed with non-metastatic prostate cancer with or without prior prostatectomy, and scheduled to receive external beam radiation therapy at the Radiation Oncology Clinic of the NIH Clinical Center. Potential participants were excluded if they had a progressive disease that could cause significant fatigue, had psychiatric disease within the past five years, had uncorrected hypothyroidism or anemia, or had a second malignancy. Individuals who used sedatives, steroids, or non....

Results

Representative force (kg) versus time (s) traces are shown in Figure 1. During the static fatigue test, subjects typically reach maximal strength (F_max) within 2–3 s²³. Self-reported fatigue in subjects was measured based on previous studies³. The absence of F_max (±10% MVIC) within 3 s indicates insufficient effort²³. To prevent this issue, verbal encouragement should be provided. Both subjects repo.......

Discussion

Here, we provide three different methods for measuring the physical dimension of CRF. Motor fatigue tests using handheld dynamometers are simple and easily adaptable for clinical use. Since many variations of the test exist in the literature, our goal was to provide standardized methods to administer these tests and decrease the need for extensive in-person trainings for clinicians.

Although the fatigue tests outlined in this study demonstrate good test-retest reliability⁷

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Quantitative Muscle Assessment application (QMA)	Aeverl Medical	QMA 4.6	Data acquisition software. NOTE: other brands/models can be used as long as the software records force over time.
QMA distribution box	Aeverl Medical	DSTBX	Software distribution box which connects the handgrip to the software.
Baseline hand dynamometer with analog output	Aeverl Medical	BHG	Instrumented handgrip device with computer assisted data acquisition. NOTE: other brands/models can be used as long as the instrument measures force over time