Measurement of the magnitude of force applied by students when learning a mobilisation technique

Abstract

Passive accessory intervertebral movements (PAIVM’s) are frequently used by physiotherapists in the assessment and management of patients. Studies investigating the reliability of passive mobilisation techniques have shown conflicting results. Therefore, standardisation of PAIVM’s is essential for research and teaching purposes, which could result in better clinical management. In order to standardise graded passive mobilisation techniques, a reliable, easy-to-use, objective measurement tool must be used. The aim of this study was to determine whether it is necessary to quantify the magnitude of force applied when teaching a grade I central posteroanterior (PA) mobilisation technique (according to Maitland) on the cervical spine. An objective measurement tool (FlexiForceTM) was used to determine the consistency of force applied by third and fourth year physiotherapy students while performing this technique. Twenty third- and 20 fourth year physiotherapy students (n=40) were randomly selected. Each subject performed a grade I central PA on sensors placed on C6 for 25 seconds. The average maximum grade 1 force applied by the third year students was significantly higher than the force applied by the fourth year students (p=0.034). There was a significantly larger variation in applied force among third years (p=0.00043). The results indicate that the current teaching method is insufficient to ensure inter-therapist reliability amongst students, emphasising the need for an objective measurement tool to be used for teaching students. The measurement tool used in this study is economical, easily applied and is an efficient method of measuring the magnitude of force. Further research is needed to demonstrate the reliability and validity of the tool to assist teaching and research in a clinical setting.

Manual Forces Applied During Posterior-to-Anterior Spinal Mobilization: A Review of the Evidence

“…Four studies reported PA mobilization forces applied to the cervical spine [22][23][24][25] (Table 3). In all studies, mobilization forces applied to the cervical spine tended to be somewhat lower than mobilization forces applied to the lumbar or thoracic spines.…”

“…Both studies reported grade I PA mobilization forces. 23,24 The recorded forces ranged from approximately 0.1 to 5 N (converted from original data, 11-500 g, with the assumption that force was applied in a smooth continuous manner as would be expected for a grade I mobilization). However, the flexible force transducer used in these 2 studies had a maximum limit of 500 g and 15% of the participants in 1 study (student physiotherapists) exceeded its capacity, resulting in loss of data.…”

“…23,24 Ultrathin (0.13 mm) and flexible independent variable resistance force transducers were positioned under each thumb of the therapist on the skin overlying the C6 spinous process. Both studies reported grade I PA mobilization forces.…”

A Comparison of Cervical Spine Mobilization Forces Applied by Experienced and Novice Physiotherapists

“…10 In contrast, other studies of cervical mobilization forces applied to asymptomatic persons report that students applied significantly higher forces for grade I and II mobilizations than therapists 17 or more experienced students. 27 In the lumbar spine, students also applied greater force for a grade II central PA mobilization prior to formal feedback on their forces. 18 A possible reason for these differences between therapists' and students' forces may be the way each group was taught to apply mobilization.…”

Intraexaminer comparison of applied kinesiology manual muscle testing of varying durations: a pilot study

“…Similar sensors have been used in research on prosthetics, ergonomics, and physical medicine. 15,16 This study compared results (strong/weak) between short (1 second) and long (3 seconds) MMTs of the same subject. The null hypothesis was good agreement between long-and short-duration muscle tests, in other words, that the duration of the test would not influence the outcome.…”