CAN GRADUATING PHYSIOTHERAPY STUDENTS ACCURATELY ESTIMATE PATELLAR TENDON FORCES DURING COMMONLY USED REHABILITATION EXERCISES?

M. Hagen¹, D. Van Assche¹, S. Verschueren¹, J. Vanrenterghem¹

¹KU Leuven, Department of Rehabilitation Sciences, Leuven, Belgium

Background: Patellar tendinopathy is a common and disabling injury among the young active population(De Vries et al., 2017). In the rehabilitation of this overuse injury, exercise therapy with a gradual progression of the patellar tendon load is considered a primary treatment option(Malliaras et al., 2015). The objective quantification of patellar tendon force (PTF) requires advanced data collection and analysis techniques, making it inaccessible to physiotherapists in clinical practice(Van Rossom et al., 2018). Physiotherapists therefore typically rely on their clinical reasoning skills and experience to estimate loading and create progressive exercise programs for individual patients.

Purpose: The objective of this study was to examine whether graduating physiotherapy students, specialising in musculoskeletal rehabilitation, are able to accurately estimate PTF during commonly used rehabilitation exercises.

Methods: One healthy individual performed two times a total of 16 rehabilitation exercises. The first time, marker-based motion capture data (100HZ; Vicon, Oxford, UK) and ground reaction forces (1000Hz; AMTI, Watertown, USA) were collected and PTF was calculated in OpenSim (Stanford, USA). The second time, the participant performed the rehabilitation exercises in a clinical setting and videos were recorded showing the frontal and sagittal plane. These videos were anonymised and implemented in an online survey. The survey was sent to 52 graduating physiotherapy students who were asked to score each rehabilitation exercise on a 100-point numerical rating scale ranging from “absolutely no patellar tendon force” to “maximal patellar tendon force”. Two statistical analyses were performed on the results. First, the difference between the scores provided by the students and the objectively quantified PTF were calculated. Both the average difference over all exercises and the difference for each individual exercise were statistically analysed using one-sample t-tests with Bonferroni correction (critical p-value=0.003). Next, the percentages were reduced to a ranking score, representing a more basic level of clinical reasoning. The overall difference between the students’ rankings and the objective PTF rankings were statistically analysed using Kendall’s tau coefficient.

Results: Students overestimated the PTF as the average difference and the differences of most individual exercises were significantly greater than zero (all p<0.001). Correct PTF estimates were found for sit-to-stance (p=0.038) and the vertical jump with squat landing (p=0.494). Only the PTF during the forward jump was underestimated (p<0.001). Kendall’s tau coefficient for the ranking scores was 0.617 (p<0.001).

Conclusions: Graduating students had moderate to good capabilities to rank rehabilitation exercises from low to high for PTF. However, the students had a general tendency to overestimate the PTF during these exercises when expressed as a percentage of the maximum PTF.

Implications: Overestimation of PTF during rehabilitation exercises suggests that graduating physiotherapy students may be too careful in the construction of patellar tendinopathy exercise programs. This may lead to unnecessarily slow or even incomplete rehabilitation processes. Assuming that direct measurement tools for PTF in clinical practices will not be available in the near future, we suggest that physiotherapy education programs should develop training opportunities for musculoskeletal load management. However, further research is necessary to elucidate whether more experience leads to better load estimations.

Funding acknowledgements: PhD Fellowship fundamental research FWO Flanders

Keywords:
Load management
Clinical reasoning
Patellar tendinopathy

Topics:
Musculoskeletal: lower limb
Education

Did this work require ethics approval? Yes

Institution: KU Leuven

Committee: Ethics Committee Research UZ/KU Leuven

Ethics number: S63980