PREMUS 2025: 12th International Scientific Conference on the Prevention of Work-Related Musculoskeletal Disorders
Measurement-based assessment of the load on the distal upper extremity during manual therapy techniques in physiotherapy
2German Social Accident Insurance for the Health and Welfare Services (BGW), Hamburg, Germany
3Institute for Health Services Research in Dermatology and Nursing (IVDP), University Medical Center Hamburg-Eppendorf, Hamburg-Eppendorf, Germany
Text
Introduction: Manual therapy techniques are a component of the daily practice of physiotherapy, occupational therapy, chiropractic, osteopathy and medical treatment and are associated with an increased risk of occupational musculoskeletal disorders (MSDs). In particular, work-related MSDs of the wrist and thumb can severely impair the job performance [1], [2]. To date, there is a lack of international studies on sensor-based recording of physiotherapeutic exposure.
For this reason, the Institute for Occupational Safety and Health (IFA) of the German Social Accident Insurance (DGUV) is developing a measurement-based approach funded by the German Social Accident Insurance for the Health and Welfare Services (BGW).
The objective of this study is to develop a methodological approach and to evaluate the load on the distal upper extremity during manual therapy techniques in physiotherapy, initially in a laboratory setting and subsequently in the field.
Methods: 15 physiotherapists (11 female, 5 male; age: 35.6±12.7y) performed massage, lymphatic drainage, trigger point therapy and spinal mobilisation on a healthy participant in a laboratory setup.
As a part of the CUELA risk assessment framework developed by the IFA, inertial sensor-based systems were used for kinematic motion capture: Xsens Metagloves (Manus) for finger and thumb kinematics were combined with Xsens Awinda sensors for whole body analysis. To analyse muscle activity, a 14-channel electromyography (EMG) system (Cometa WavePlus) was placed according to Jarque-Bou et al. [3]. A portable force measurement device was developed to measure the force applied during the simulated performance of therapy techniques. Furthermore, passive range of motion (ROM) was measured using a goniometer.
Results: Maximum wrist extension ranged from 52±17° (spinal mobilisation) to 78±17° (massage) and was close to the passive extension of 81±8°.
Mean ROM of the fingers (MCP joint) and thumb (CMC joint) was highest for massage (fingers: from 52±18° 5th phalange to 59±10° 3rd phalange; thumb: 60±27°). EMG activity (90th percentile) of the fingers and thumb resulted in 33 to 48% of maximal voluntary activation across all manual therapy techniques. Spinal mobilisation forces were highest at around 170 N.
Discussion: All manual therapy techniques resulted in high load on the wrist and thumb CMC joint. The highest kinematic loads occurred during massage, and the greatest force during spinal mobilisation corresponding to the literature [4]. The muscle activity was up to four times higher than a transportations task using 2,5–3,0 kg products and the same EMG placement [5]. Sub-techniques need to be further analysed.
Conclusion: The measurement approach was successfully applied to all physiotherapists and can be transferred to field study. It can be helpful tool to analyse manual therapy techniques.
Literatur
[1] Glover W, McGregor A, Sullivan C, Hague J. Work-related musculoskeletal disorders affecting members of the Chartered Society of Physiotherapy. Physiotherapy. 2005;91(3):138-47. DOI: 10.1016/j.physio.2005.06.001[2] Waller E, Bowens A, Washmuth N. Prevalence of and prevention for work-related upper limb disorders among physical therapists: a systematic review. BMC Musculoskelet Disord. 2022 May 14;23(1):453. DOI: 10.1186/s12891-022-05412-8
[3] Jarque-Bou NJ, Vergara M, Sancho-Bru JL, Gracia-Ibáñez V, Roda-Sales A. A calibrated database of kinematics and EMG of the forearm and hand during activities of daily living. Sci Data. 2019 Nov 11;6(1):270. DOI: 10.1038/s41597-019-0285-1
[4] Gagnon DH, Longtin C, Berbiche D, Gaudreault N. Do experienced physiotherapists and final year physiotherapy trainees apply similar force during posterior-to-anterior lumbar mobilization techniques? Man Ther. 2016 Feb;21:287-91. DOI: 10.1016/j.math.2015.05.002
[5] Roda-Sales A, Jarque-Bou NJ, Bayarri-Porcar V, Gracia-Ibáñez V, Sancho-Bru JL, Vergara M. Electromyography and kinematics data of the hand in activities of daily living with special interest for ergonomics. Sci Data. 2023 Nov 20;10(1):814. DOI: 10.1038/s41597-023-02723-w
