Is it time to rethink using digital palpation for assessment of muscle stiffness?

Abstract

Aim: Physiotherapists typically use digital palpation to determine residual tension in a muscle, referred to as muscle stiffness or tone. These assessments are subjective, and little is known about their accuracy or repeatability. Despite this, it is standard practice to base clinical treatment on these findings. The aim of this study was to assess physiotherapists' ability to assign a seven-point palpation scale to quantitative stiffness values generated by a novel device. Methods: Prospective observational study involving 125 musculoskeletal and pelvic floor physiotherapists. A novel device was developed that replicates the haptic feedback that clinicians assess as muscle stiffness. Measurements of displacement, force, and stiffness were recorded.Results: There was wide overlap between each scale category assigned to the stiffness values, from low stiffness at −3 (119 [106, 132] N/m) to moderate stiffness at 0 (462 [435,489] N/m); to high stiffness at +3 (897 [881,913] N/m). Consistency in applying the scale was poor, and the probability of a similar value of stiffness being assigned to the same scale category by different participants was low.Conclusions: While palpation is used globally by physiotherapists as a readily available and low-cost method of assessing muscle stiffness, these results indicate that it should be used with caution in diagnosing and defining patient care. Clinical assessment of muscle stiffness requires a validated and reliable palpation scale if this metric is to be used to diagnose pathology and develop treatment protocols. Training in this scale should then be recommended to improve reliability in patient assessment. K E Y W O R D S assessment, digital palpation, muscle stiffness, scale, tone

Reliability of Myotonometric Measurement of Stiffness in Patients with Spinal Cord Injury

“…The modified Ashworth Scale, palpation, and the pendulum test are usually used to evaluate joint stiffness clinically [ 6 , 7 ]. Although these methods have been used globally by physiotherapists because they are low cost, they have been criticized for subjective limitations and non-repeatability [ 6 , 8 , 9 ]. Shear wave elastography (SWE) also has been used to quantitatively assess muscle and tendon stiffness [ 10 , 11 ], but it requires more expensive equipment and more professional operating skills.…”

Relationship between the types of urinary incontinence, handgrip strength, and pelvic floor muscle strength in adult women

“…21 Nonetheless, due to the subjective nature of the technique in evaluation of PFMS, it may not be as accurate as quantitative measurements. 22 Our study finding, that no relationship was identified between vaginal digital palpation and perineometer measurements, may be explained by this case. The ICS recommends manometric measures to assess PFM function.…”

“…Vaginal digital palpation is a method that is easily applicable for PFMS measurement, widely used and known to be well tolerated by patients 21 . Nonetheless, due to the subjective nature of the technique in evaluation of PFMS, it may not be as accurate as quantitative measurements 22 . Our study finding, that no relationship was identified between vaginal digital palpation and perineometer measurements, may be explained by this case.…”

Manual Therapy: Art or Science?

“…Similar analyses have been performed as to the palpatory assessment of extra-articular soft tissues, thereby showing that even very experienced assessors are hardly able to identify the anatomical location of the target tissues [48], grade the muscle stiffness [49], pinpoint any tissue dysfunction, or tell a subject with pain from a healthy one. In some cases, even the creators of some of the methods proved inadequate [50].…”