Calf-raise senior: a new test for assessment of plantar flexor muscle strength in older adults: protocol, validity, and reliability

Abstract

Purpose

This study aimed to develop a new field test protocol with a standardized measurement of strength and power in plantar flexor muscles targeted to functionally independent older adults, the calf-raise senior (CRS) test, and also evaluate its reliability and validity.

Patients and methods

Forty-one subjects aged 65 years and older of both sexes participated in five different cross-sectional studies: 1) pilot (n=12); 2) inter- and intrarater agreement (n=12); 3) construct (n=41); 4) criterion validity (n=33); and 5) test–retest reliability (n=41). Different motion parameters were compared in order to define a specifically designed protocol for seniors. Two raters evaluated each participant twice, and the results of the same individual were compared between raters and participants to assess the interrater and intrarater agreement. The validity and reliability studies involved three testing sessions that lasted 2 weeks, including a battery of functional fitness tests, CRS test in two occasions, accelerometry, and strength assessments in an isokinetic dynamometer.

Results

The CRS test presented an excellent test–retest reliability (intraclass correlation coefficient [ICC] =0.90, standard error of measurement =2.0) and interrater reliability (ICC =0.93–0.96), as well as a good intrarater agreement (ICC =0.79–0.84). Participants with better results in the CRS test were younger and presented higher levels of physical activity and functional fitness. A significant association between test results and all strength parameters (isometric, r=0.87, r²=0.75; isokinetic, r=0.86, r²=0.74; and rate of force development, r=0.77, r²=0.59) was shown.

Conclusion

This study was successful in demonstrating that the CRS test can meet the scientific criteria of validity and reliability. The test can be a good indicator of ankle strength in older adults and proved to discriminate significantly between individuals with improved functionality and levels of physical activity.

Keywords:

• elderly
• heel-raise test
• ankle
• isometric
• strength
• functionality

Acknowledgments

The authors are grateful to all the older adults who volunteered to participate in this study. This work was supported by the Portuguese Foundation for Science and Technology (project reference PTDC/DES/72946/2006 and PhD Grant reference SFRH/BD/62429/2009). The funding source of the study had no role in the design, implementation, recruitment, data collection and analysis, or the preparation of this manuscript.

Disclosure

The authors report no conflicts of interest in this work.