Validity and reliability of serratus anterior hand held dynamometry

Abstract

Background Strength testing of the serratus anterior muscle with hand held dynamometry (HDD) in supine subjects has low reproducibility, and is influenced by compensatory activity of other muscles like the pectoralis major and upper trapezius. Previously, two manual maximum voluntary isometric contraction tests of the serratus anterior muscle were reported that recruited optimal surface electromyography (sEMG) activity in a sitting position. We adapted three manual muscle tests to make them suitable for HHD and investigated their validity and reliability. Methods Twenty-one healthy adults were examined by two assessors in one supine and two seated positions. Each test was repeated twice. Construct validity was determined by evaluating force production (assessed with HHD) in relation to sEMG of the serratus anterior, upper trapezius and pectoralis major muscles, comparing the three test positions. Intra- and interrater reliability were determined by calculating intra-class correlation coefficients (ICC) smallest detectable change (SDC) and standard error of measurement (SEM). Results Serratus anterior muscle sEMG activity was most isolated in a seated position with the humerus in 90° anteflexion in the scapular plane. This resulted in the lowest measured force levels in this position with a mean force of 296 N (SEM 15.8 N). Intrarater reliability yielded an ICC of 0.658 (95% CI 0.325; 0.846) and an interrater reliability of 0.277 (95% CI -0.089;0.605). SDC was 127 Newton, SEM 45.8 Newton. Conclusion The results indicate that validity for strength testing of the serratus anterior muscle is optimal with subjects in a seated position and the shoulder flexed at 90° in the scapular plane. Intrarater reliability is moderate and interrater reliability of this procedure is poor. However the high SDC values make it difficult to use the measurement in repeated measurements.

Visuomotor processing is altered after peripheral nerve damage in neuralgic amyotrophy

“…We estimated the maximal force exerted with the serratus anterior muscle, which is often affected in NA patients, 14 with a manual digital dynamometer (MicroFET2®). 39 The DASH is a validated questionnaire that measures the functional capability of the upper extremity. Scores range from 1 to 100 with higher scores reflecting more impairment.…”

The Management of Valgus Extension Overload Syndrome Experienced with Hitting in a High School Baseball Player: A Case Report

“…Pelvic and lower quarter normative data exist for batting, 61,67 and therefore video analysis may have revealed whether the integration of specific pelvic and trunk retraining during physical therapy was actually needed. Additionally, certain physical examination measures such as manual muscle testing in the shoulder possess questionable interrater reliability and reproducibility 68 and should be interpreted with caution.…”

Correlation of scapulothoracic muscle strength and functional activity in volleyball players

“…Subjects who fit the inclusion criteria and exclusion criteria were selected and their strength of muscle (serratus anterior, lattissimus dorsi, lower trapezius, rhomboids, pectoralis major) was measured by handheld dynamometer and all readings were noted. 5,6 Then asked them to fill DASH scale. 3 Reading were noted and accordingly calculated DASH scale score by formula.…”

“…1 Also athletes having overhead activities reported to decrease in strength of lower trapezius muscle. [2][3][4][5] Scapulothoracic muscles are stabilizing muscles of scapula as per biomechanics. Lesser the muscle strength or endurance of scapulothoracic muscles can cause scapular dyskinesia or muscular imbalance.…”