Evaluation of hip abductor and adductor strength in the elderly: a reliability study

Abstract

BackgroundIn elderly individuals an increased muscle strength contributes to the diminution of the falls risk and associated adverse events. An increasing interest in lateral control exists due to the fatal consequences of postero-lateral falls. Therefore a proper assessment of frontal plane hip muscle strength in elderly is important but remains challenging.Therefore we aimed to investigate the feasibility and repeatability of a hip abductor and adductor maximum voluntary isometric strength (MVIS) and rate of force generation (RFG) test in elderly. This represents an initial step in the development process of a new and clinically relevant test that could lead to more specific treatment protocols for this population.MethodsIn this measurement focused study hip abduction (ABD) and adduction (ADD) MVIS and RFG were tested twice within one to three hours with a dynamometer fixed to a custom made frame in a geriatric population including fallers and non-fallers. Intraclass correlation coefficient (ICCagreement), standard error of measurement (SEM), and smallest detectable difference (SDD) were determined.ResultsAll recruited persons (N = 76; mean age (SD) 80.46 (7.05) years old) completed the tests. The average time needed to complete the strength tests was 10.58 min. (1.56) per muscle group. The reliability of the hip ABD and ADD was high with ICC’sagreement ranging from 0.83 to 0.97. The SDD varied between 18.1 and 81.8% depending on the muscle group and type of strength that was evaluated.ConclusionHip abductor and adductor strength measures in older person are feasible and reliable. However, the significance of moderate changes in these measurements may be limited by the large SDD and SEM. Therefore, physical therapist should be careful when using this measure for assessing the progress of an individual person in a daily clinical use.

Hip muscle and hand-grip strength to differentiate between older fallers and non-fallers: a cross-sectional validity study

“…The method of measuring hip ABD, by a dynamometer fixed to a custom-made frame attached to a regular physical therapy treatment table, we chose in this study is practicable and feasible with older adults in everyday clinics. 20 The time to install and measure participants’ hip ABD is 10.58±1.56 minutes. 20 Further, our measurement method was proven in our earlier article to have a good reliability.…”

“… 20 The time to install and measure participants’ hip ABD is 10.58±1.56 minutes. 20 Further, our measurement method was proven in our earlier article to have a good reliability. 20 …”

“…Hip strength was measured in Newton (N) using an analog dynamometer (SENSIX ® ; Sensix, Poitiers, France) with a measuring range from 0 to 667 N and a precision of 0.002 N. The DELSYS System (Trigno Sensor; Delsys, Inc, Boston, MA, USA) coupled with the calibrated dynamometer digitalized the output (3.3 V) with a sampling rate of 1,926 Hz and a resolution of 16 bit. 20 To avoid bias induced by the testing people, the dynamometer was fixed to a frame for all strength tests. Hip MVIS (N/kg) and RFG (N/s/kg) were assessed in all anatomic planes.…”

Intra-rater reliability of hip abductor isometric strength testing in a standing position in older fallers and non-fallers

“…The signal was low-pass filtered (75 ms moving average) to attenuate high-frequency noise. Three dependent variables were extracted: test duration (s), MVIS (N) and RFG (N/s) [ 13 , 17 ]. MVIS was defined as the peak value reached within four seconds, and RFG was evaluated during the 50 ms after 10% of MVIS was reached [ 13 ].…”

“…However, the measurement of hip abductor muscle strength in the clinical setting is challenging and thus very few studies assessed psychometric properties of available strength tests [ 12 – 14 ]. A previous study in our group highlighted the feasibility and good intra-rater reliability of a hip abductor strength test in a side-lying position in older people [ 13 ]. In healthy young subjects, Widler et al [ 12 ], showed that this position has the most valid and reliable results compared to supine and standing positions.…”