The Effect of Diathermy Therapy on Isolated Lumbar Extension (ILEX) Training
Phase: NA
Conditions: Resistance Training, Healthy Participants Study
Sponsor: University of Applied Sciences and Arts of Southern Switzerland

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The effect of diathermy therapy on isolated lumbar extension (ILEX) training 
Req-2023-02308 
The effect of diathermy therapy on isolated lumbar extension (ILEX) 
training 
 
 
 
 
Study Type: 
 Other Clinical Trial according to ClinO, Chapter 4 
 
Risk Categorisation:  
Risk category A according to ClinO, Art. 61 
 
Study Registration: 
1. Swiss National Clinical Trial Portal 
2. NCT06852872 
 
Sponsor: 
Thim van der Laan jr 
 
Thim van der Laan AG 
Weststrasse 8 
 
7302 Landquart 
 
+41 81 300 01 70 
 
Principal Investigator 
 Dr. Ron Clijsen, PhD 
University of Applied Sciences of Southern Switzerland SUPSI 
Rehabilitation and Exercise Science Laboratory (RES Lab) 
Weststrasse 8  
7302 Landquart 
 
+41 81 300 01 75 
 
Investigated Intervention: 
6 weeks of training on an isolated back extensor (ILEX) training 
machine combined with a prior diathermy treatment. 
 
Protocol ID 
 
 
Req-2023-02308 
 
Version and Date: 
 
Version 04 (dated 19/03/2024) 
 
 
CONFIDENTIALITY STATEMENT 
The information contained in this document is confidential and the property of Thim van der Laan 
AG. The information may not - in full or in part - be transmitted, reproduced, published, or 
disclosed to others than the applicable Competent Ethics Committee(s) and Regulatory 
Authority(ies) without prior written authorisation from the sponsor except to the extent necessary 
to obtain informed consent from those who will participate in the study. 
 
 

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PROTOCOL SIGNATURE FORM    
 
 
Study Title 
The effect of diathermy therapy on isolated lumbar 
extension (ILEX) training 
Study ID 
Req-2023-02308 
 
The Sponsor has approved the protocol version 04 (dated 09/03/2024) and confirm hereby to 
conduct the study according to the protocol, current version of the World Medical Association 
Declaration of Helsinki, and ICH-GCP guidelines as well as the local legally applicable 
requirements. 
 
Sponsor: 
 
Name: Thim van der Laan jr.  
Date: 
 _________________________ 
Signature:  ___________________________  
 
 
Principal Investigator: 
 
Name: Dr. Ron Clijsen 
Date: 
 _________________________ 
Signature:  ___________________________  
 
 
 

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TABLE OF CONTENTS 
TABLE OF CONTENTS 
3 
GLOSSARY OF ABBREVATIONS 
4 
1 STUDY SYNOPSIS 
5 
2 BACKGROUND AND RATIONALE 
6 
3 STUDY OBJECTIVES AND DESIGN 
7 
3.1 Hypothesis and primary objective 
7 
3.2 Primary and secondary endpoints 
8 
3.3 Study design 
10 
3.4. Study intervention 
10 
4 STUDY POPULATION AND STUDY PROCEDURES 
11 
4.1 Inclusion and exclusion criteria, justification of study population 
11 
4.2 Recruitment, screening and informed consent procedure 
12 
4.3 Study procedures 
12 
4.4 Withdrawal and discontinuation 
14 
5 STATISTICS AND METHODOLOGY 
14 
5.1. Statistical analysis plan and sample size calculation 
14 
5.2. Handling of missing data and drop-outs 
14 
6 REGULATORY ASPECTS AND SAFETY 
14 
6.1 Local regulations / Declaration of Helsinki 
14 
6.2 (Serious) Adverse Events and notification of safety and protective measures 
14 
6.3 (Periodic) safety reporting 
16 
6.4 Radiation 
16 
6.5 Pregnancy 
16 
6.6 Amendments 
16 
6.7 Notification and reporting upon completion, discontinuation or interruption of the study
 
16 
6.8 Insurance 
16 
7 FURTHER ASPECTS 
17 
7.1 Overall ethical considerations 
17 
7.2 Risk-benefit assessment 
17 
8 QUALITY CONTROL AND DATA PROTECTION 
17 
8.1 Quality measures 
17 
8.2 Data recording and source data 
17 
8.3 Confidentiality and coding 
17 
8.4 Retention and destruction of study data and biological material 
18 
9  MONITORING AND REGISTRATION 
18 
10. FUNDING / PUBLICATION / DECLARATION OF INTEREST 
19 
11. REFERENCES 
20 
Appendix 1: Schedule of assessments (if applicable) 
24 
 
 

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GLOSSARY OF ABBREVATIONS 
 
AE 
Adverse Event 
ASR 
Annual Safety Repot 
BASEC 
Business Administration System for Ethical Committees 
BL  
 
Baseline 
CR-10 
Category-Ratio-Scale 
CRF 
Case Report Form 
CTCAE 
Common Terminology Criteria for Adverse Events 
FADP 
Federal Act on Data Protection (in German: DSG, in French: LPD, in Italian: LPD) 
eCRF 
electronic Case Report Form 
FOPH 
Federal Office of Public Health 
F/U1   
Follow-up 1 
F/U2   
Follow-up 2 
GCP 
Good Clinical Practice 
HSPs 
Heat shock proteins 
HRA 
Human Research Act (in German: HFG, in French: LRH, in Italian: LRUm) 
ICH 
International Conference on Harmonisation 
ILEX 
Isolated lumbar extension  
LBP  
Low back pain 
MF 
Momentary failure 
ClinO 
Ordinance on Clinical Trials in Human Research (in German: KlinV, in French: 
OClin, in Italian: OSRUm) 
RCT 
Randomized controlled trial 
RESLab 
Rehabilitation and Exercise Science Laboratory 
RPE-D 
Rating of perceived discomfort 
RPE-E 
Rating of perceived effort 
ROM 
Range of motion 
SAE 
Serious Adverse Event 
YLD 
Years lived with disability 
 
 

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1 
STUDY SYNOPSIS 
Sponsor / 
Sponsor-
Investigator 
Name(s) and contact details of Sponsor / Sponsor-Investigator 
Study Title 
Full protocol title 
Short Title / 
Study ID 
Abbreviated protocol title or, if applicable, study ID, e.g. study number 
Protocol Version 
and Date 
Version x (dated DD/MM/YYYY) 
Study 
Registration 
Name of study registry, registration number (if not yet registered, name the intended registry) 
Study Category 
and Rationale 
Risk category and rationale 
Background and 
Rationale  
Background of the study and rationale 
Risk / Benefit 
Assessment 
Risk / benefit assessment 
Objective(s) 
Primary objective(s) and, if applicable, secondary including safety objective(s) 
Endpoint(s) 
Primary endpoint(s) and, if applicable, secondary including safety endpoint(s) 
Study Design 
Design attributes (e.g. confirmatory, non-randomised / randomised, open / single-blinded /  
one-arm / two-arm, cross-over/controlled)  
Statistical 
Considerations 
Description of the main elements of the statistical methodology to be used in the study 
including an explanation to sample size 
Inclusion- / 
Exclusion 
Criteria 
key inclusion and exclusion criteria and, if applicable, rationale for including vulnerable 
participants 
Number of 
Participants with 
Rationale 
Number of participants in the entire study, provide the total number as well as the number for 
each treatment group. Briefly explain the rationale for the number of participants. 
Study 
Intervention 
Description of the study intervention 
Control 
Intervention 
If applicable, description of the control group 
Study 
procedures 
Description of the overall study procedures  
Study Duration 
and Schedule 
Estimated duration for the main investigational plan, i.e. from start of screening of first 
participant to last participant last visit and finishing the study 
 
Planned MM/YYYY of First-Participant-In 
Planned MM/YYYY of Last-Participant-Out 
Investigator(s) 
Name(s) and contact details of Investigator(s) 
Study Center(s) 
Name(s) and address of Study Center(s) 
If multicenter study, number of centers to be involved If multinational study, countries to be 
involved 
Data privacy 
Explain how the privacy of data is guaranteed. Mention coding and confidentiality while 
handling data and if applicable biological material. 
Ethical 
consideration 
Explain the scientific value of the study, justify the methodology give a statement to the risks 
and the benefit. Explain if you include vulnerable populations.  
GCP Statement 
This study will be conducted in compliance with the protocol, the current version of the 
Declaration of Helsinki, the ICH-GCP, the HRA as well as other locally relevant legal and 
regulatory requirements. A clinical trial covered by ClinO Chapter 4 may be conducted in 
accordance with other rules than ICH-GCP guidelines, provided that such rules are recognised 
in the specialty in question and the protection of participants and data quality and security are 
guaranteed (ClinO Art. 5, Abs 2). If the clinical trial is not conducted according to ICH-GCP 
guidelines, the paragraph above must be adapted accordingly. 
 

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2 
BACKGROUND AND RATIONALE  
Low back pain (LBP) constitutes a global public health concern, affecting an estimated 619 
million individuals across all age groups (Collaborators, 2023; Hartvigsen et al., 2018; Hoy et 
al., 2012). Projections, based on trends in population growth and aging, suggest that by the 
year 2050, there will be a further increase of 36.4%, resulting in a total of 843 million individuals 
worldwide affected by LBP (Collaborators, 2023). In 2020, low back pain accounted for a 7.7% 
of all years lived with disability (YLD) globally, establishing it as the primary cause of the world’s 
disability burden, accompanied with substantial associated costs of care (Collaborators, 2023). 
Approximately one third of individuals experience a recurrence of low back pain within one year 
after recovering from a prior episode (da Silva et al., 2017). For most individuals presenting with 
low back pain, to pinpointing a specific cause proves challenging. Consequently, these 
individuals are classified as having non-specific low back pain (Maher et al., 2017). While there 
are numerous potential causes of LBP, it has been suggested that these often relate to 
weakness of the muscles responsible for extending the lumbar spine (lumbar erector spinae 
and multifidus) (Steele et al., 2014).  
 
Isolated lumbar extension (ILEX) training utilizing resistance machines has demonstrated 
superior effectiveness in strengthening the lumbar extensors compared to alternative methods 
such as bench and roman chair trunks extensions, free weight exercises, or floor and stability 
ball exercises (Steele et al., 2015b). Furthermore, ILEX resistance training has shown efficacy 
in reducing pain and improving disability associated with LBP (Steele et al., 2015a). What sets 
ILEX resistance machines apart is their unique ability to isolate the lumbar muscles to be 
primarily responsible for the work performed by stabilizing the pelvis through specially designed 
restraints. Previous studies have documented the necessity of pelvic stabilization in order to 
optimal increases in low back strength by eliminating the contribution of gluteal and hamstring 
muscles (Graves et al., 1994; Smith et al., 2011). Moreover, it has been established that a semi-
sitting position is the most effective to reduce the activation of the hip extensor muscle (da Silva 
et al., 2009).  
 
Exercise training is a powerful stimulus for physiological adaptations and a crucial aspect of 
maintaining good health (Egan & Zierath, 2013). Resistance exercises are particularly effective 
in enhancing skeletal muscle development, growth, and function (Egan & Zierath, 2013). 
However, factors such as limited physical capabilities and poor health status can prevent 
individuals from meeting the recommended level of exercise (Fennel et al., 2022). Recently, 
there has been an increasing interest in the potential of heat as adaptive aid to promote 
hypertrophy in resistance training. There is some evidence that heat stress alone (Ihsan et al., 
2020; Rodrigues et al., 2020) and in combination with resistance exercise (Goto et al., 2007; 
Nakamura et al., 2019; Yoon et al., 2017) can increase hypertrophy and associated muscle 
strength. Heat shock proteins (HSPs), expressed in response to stimuli including heat stress 
and exercise, play a critical role in protecting from muscular atrophy or confer hypertrophic 
benefits (Fennel et al., 2022). The exact mechanisms by which HSPs might associate with or 
influence relevant signalling responses in skeletal muscle are not fully elucidated (Fennel et al., 
2022). It has been known that expression of HSPs in skeletal muscle increases when the 
muscle temperature is increased over 40°C (Oishi et al. 2002 (Oishi et al., 2002; Selsby & 
Dodd, 2005). To date, four studies have investigated the impact of repeated heat stress in direct 
combination with resistance training over a period of several weeks (Goto et al., 2007; 
Nakamura et al., 2019; Stadnyk et al., 2018; Yoon et al., 2017). Three studies found a beneficial 
effect (Goto et al., 2007; Nakamura et al., 2019; Yoon et al., 2017), whilst one study reported no 
evident advantages (Stadnyk et al., 2018). Training protocols, involved muscle groups, as well 
as type and duration of heat applications varied in the four studies. Nakamura and colleagues 
concluded that incorporating heat stress prior to resistance training, rather than afterwards, may 
be crucial for enhancing muscle mass and increasing strength (Nakamura et al., 2019). To the 
best of our knowledge, no studies have been published to investigate the effect of heat stress 
and resistance training on the back extensor muscle.  

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Different methods can be used to heat the whole body or specific body areas. Shortwave or 
microwave electromagnetic diathermy is a heating modality that uses a radiofrequency 
electromagnetic field to increase the temperature in deeper structures, such as muscles, without 
an excessive increase of skin temperature to uncomfortable levels (Guy et al., 1974). 
Microwave diathermy has shown to increase muscle temperature by ~3-7°C depending on the 
time of application and power of the instrument (Castellani et al., 2016; Draper et al., 1999; 
Nosaka et al., 2007; Nosaka et al., 2004).   
 
The aim of this study is to investigate strength gains of the back extensor after 6 weeks of 
resistance training on an ILEX machine in combination with microwave diathermy.  
 
3 
STUDY OBJECTIVES AND DESIGN  
3.1 Hypothesis and primary objective 
The main aim of this study is to investigate the effect of back extensor strength after 6 weeks of 
ILEX training and diathermy therapy.  
 
• 
H0: 6 weeks of resistance training on the ILEX machine does not improve lumbar extensor 
muscle strength. 
 
• 
H1: 6 weeks of resistance training on the ILEX machine improves the strength of the lumbar 
extensor muscle.  
 
• 
H0: There is no difference in the improvement in lumbar extensor muscle strength between 
those who receive a microwave diathermy treatment before each resistance training session 
and those in the sham group.  
 
• 
H1: Individuals who receive a microwave diathermy treatment prior to each resistance 
training session improve their lumbar extensor muscle strength more than those in the sham 
group.  
 
Secondary objectives are to examine the development of M. erector spinae thickness, isometric 
back extension endurance, and lumbar extensor flexibility after 6 weeks of resistance training 
and diathermy therapy. 
 
• 
H0: 6 weeks of resistance training on the ILEX machine does not enhance the thickness of 
the M. erector spinae.   
 
• 
H1: 6 weeks of resistance training on the ILEX machine enhances the thickness of the M. 
erector spinae.   
 
• 
H0: There is no difference in the increase of the thickness of the M. erector spinae between 
those who receive a microwave diathermy treatment before each resistance training session 
and those in the sham group. 
 
• 
H1: Individuals who receive a microwave diathermy treatment prior to each resistance 
training session enhance the thickness of the M. erector spinae more than those in the 
sham group.    
 
• 
H0: 6 weeks of resistance training on the ILEX machine does not improve isometric back 
extension strength endurance.   

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• 
H1: 6 weeks of resistance training on the ILEX machine improves isometric back extension 
strength endurance.   
 
• 
H0: There is no difference in the improvement of the isometric back extension strength 
endurance between those who receive a microwave diathermy treatment before each 
resistance training session and those in the sham group. 
 
• 
H1: Individuals who receive a microwave diathermy treatment prior to each resistance 
training session improve the isometric back extension strength endurance more than those 
in the sham group.    
 
• 
H0: 6 weeks of resistance training on the ILEX machine does not increase lumbar ROM.   
 
• 
H1: 6 weeks of resistance training on the ILEX machine increases lumbar ROM.   
 
• 
H0: There is no difference in the increase of the lumbar ROM between those who receive a 
microwave diathermy treatment before each resistance training session and those in the 
sham group. 
 
• 
H1: Individuals who receive a microwave diathermy treatment prior to each resistance 
training session increase of the lumbar ROM more than those in the sham group.    
 
3.2 Primary and secondary endpoints 
Primary endpoint  
Maximal isometric force of the back extensor  
The maximum voluntary isometric contraction (in Newtons) of the back extensor is measured 
with the CE-certified ILEX machine Myosom (Heftec GmbH, Oberurnen, Switzerland)  before, 
after 6 sessions and after 12 sessions of resistance training and diathermy therapy to examine 
strength growth. ILEX resistance machines are designed to primarily train the lumbar muscles 
by stabilizing the pelvis through specially designed restraints (Steele et al., 2015b). Participants 
are seated in the machine in a semi-sitting position with the feet placed on a footrest and the 
thoracal back leaned against a squared restrained. The movement arm is locked causing a 
slight flexion in the lumbar back and restrain belts are secured around the pelvis and shoulders. 
The participants are advised to extend their back slowly and continuously against the upper-
back pad for 2 to 3 seconds. Peak torque is registered electronically.  
 
Secondary endpoints 
Isometric back extension strength endurance 
Isometric back extension endurance (in seconds) is assessed using the Biering-Sørensen test 
before, after 6 sessions and after 12 sessions of resistance training and diathermy therapy to 
confirm the strength growth in the back extensor. The Biering-Sørensen test is the most widely 
used test in published studies evaluating the isometric endurance of trunk extensor muscles. It 
is a rapid, simple, and reproducible test (Demoulin et al., 2006). The participant is lying prone 
on an examination table with the upper border of the iliac crests in line with the edge of the 
table. The lower body is secured to the table by three straps around the pelvis, knees, and 
ankles. With the arms folded across the chest, the participant is asked to hold the upper body 
isometrically in a horizontal position. It is measured how many seconds the participant can keep 
the unsupported upper body touching a horizontal object (Biering-Sørensen, 1984).  
 
Thickness of M. erector spinae 
The thickness of the M. erector spinae (in millimeter) is measured using the ultrasound system 
Mylab2 (Esaote, Maastricht, Netherlands) in B-mode and the software HorosTM (Horos Project, 

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Annapolis, MD, USA) before, after 6 sessions and 12 sessions of resistance training to confirm 
the strength growth in the back extensor. Muscle strength is associated with the cross-sectional 
area of the muscles (Jones et al., 2008) and measuring the thickness of the M. erectors spinae 
with ultrasound has been shown to be a safe and easy method for estimating back muscle 
strength (Fujiwara et al., 2017). The participant is lying prone on the examination table. The 
probe head is coated with coupling gel and applied perpendicular to the muscle on the right side 
without pressure to not compress the dermal surface. The thickness of the longissimus is 
defined as the distance between the midpoints of fascia posterior and the outermost point of 
transversus process of the L3 vertebra (Fujiwara et al., 2017).    
 
Lumbar flexibility  
There is evidence that strength training is effective in improving the ROM (Afonso et al., 2021). 
Moreover, a diminished ROM is associated with muscle weakness. The lumbar flexibility is 
assessed with the help of a goniometer built into the ILEX machine and the sit-and-reach test 
before, after 6 sessions and 12 sessions of resistance training to control its association with the 
muscle strength growth. Participants are seated in the ILEX machine in a semi-sitting position 
with the feet placed on a footrest and the thoracal back leaned against a squared restrained. 
Restrain belts are secured around the pelvis and shoulders. The movement arm is deblocked 
and the participants are advised to move dynamically backwards and forwards as far as 
possible. Three repetitions are done, and peak flexion and extension are registered 
electronically. Additionally, the combined flexibility of the M. erector spinae and hamstrings is 
measured using the sit-and-reach test. The sit-and-reach test is probably the most widely used 
lineal measure of flexibility and it is a simple, easy to administer test with requiring minimal 
skills. The participant is seated in front of the test box, keeping the knees fully extended and the 
feet dorsiflexed against the foot-support. The participant is moving actively, slowly forward, 
bringing the body to the pain-free limit. The participant's hands move the block along the scale 
until the movement is terminated because the participant can go no farther. The final position is 
held with an isometric contraction for 2 seconds, and the distance is read on the scale. The test 
is repeated twice and an average score is taken for further analysis (Holt et al., 1999).  
 
Skin temperature 
Radiofrequency-based therapy at 448kHz in the capacity mode increases skin temperature by 
around 3°C (Kumaran & Watson, 2015). Skin temperature in the area of the M. erector spinae is 
measured twice, immediately after the first and last diathermy therapy, using infrared thermal 
imaging (FLIR A615 series, Emitec Industrial, Rotkreuz, Switzerland) and data analysis software 
(FLIR ResearchIR Max). Participants are placed on an examination table to receive the 
diathermy treatment. The camera is installed on top of the examination table to take a picture of 
the right side of the erector spinae immediately after the treatment without the participant 
moving.  
 
Rating of perceived effort (RPE-E)  
Training to momentary failure (MF) is considered to be optimal for improving strength. In 
submaximal efforts, the dose-response relationship for adaptations is not fully clear yet (Steele 
et al., 2016). The rating of perceived effort (RPE-E) provides a valid and easily accessible 
measure of exercise intensity in resistance training (Lea et al., 2022). We use the Borg’s 
Category-Ratio-Scale (CR-10) for strength training (Buckley & Borg, 2011) which is based on 
the original 15-grade Borg’s scale for ratings of perceived exertion (Borg, 1982). Immediately 
after completion of every single of the 12 training sessions on the back extensor machine, the 
examiner asks the participant “How hard do you think you’re working?”. The participant reports 
her/his perceived effort verbally with a number from 0 (no exertion at all) to 10 (maximal effort) 
orientating on a scale visually.   
 
Rating of perceived discomfort (RPE-D)  
Particularly in resistance training it is important to differentiate between the perception of effort 
(RPE-E) and discomfort (RPE-D) (Steele et al., 2016). Discomfort is the physiological and 

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unpleasant sensations associated with exercise. Increasing number of repetitions and longer 
time under muscular tension leads to higher discomfort. Therefore, higher discomfort is 
experienced in low load than in high load training (Fisher et al., 2018). We use a Category-
Ratio-Scale (CR-10) for the RPE-D (Steele et al., 2016). Immediately after the completion of 
each of the 12 training sessions on the ILEX machine, the participant is asked to report her/his 
perceived discomfort verbally with a number from 0 (no discomfort) to 10 (maximal discomfort) 
orientating on a scale visually. 
 
Rating of thermal sensation  
Immediately after each of the 12 diathermy treatments, the participant is asked to rate the 
thermal sensation in the area of the back extensor according to the ISO 10551. The participant 
rates thermal sensation (“How does this feel like?”) using a 9-point Likert scale from 4 (very hot) 
to -4 (very cold) (Fabbri, 2015).  
 
Rating of perceived comfort  
After completion of the rating of thermal sensation, participants are asked to rate the comfort felt 
during the diathermy treatment on a 5-point scale ranging from 0 “angenehm” to 4 “äusserst 
unangenehm” (1 “etwas unangenehm”, 2”unangenehm”, 3 “sehr unangenehm”) (Zhang et al., 
2004).   
3.3 Study design  
This is a monocentric clinical trial with minimal risks and burden of the risk class A (KlinV, Art. 
20). A block randomization with covariates (i.e. sex) is used. The preheating is done as a single 
blinded randomized controlled trial (RCT) with the sham group receiving a 10-minute diathermy 
treatment with the Tecar device turned off and not sending radiofrequency before each exercise 
session. The intervention group undergoes a 10-minute treatment with the Tecar device to 
induce 448kHz capacitive monopolar radiofrequency and facilitate warming up of deep tissues. 
In order to be able to carry out a single-blind situation as far as possible, the test subjects are 
not told that the therapy causes heat of the deep tissue and that this is the factor being 
investigated. Instead, we speak of high-frequency Tecar therapy and its known use to promote 
tissue healing processes.   
3.4. Study intervention 
We recruit a cohort of 14 healthy persons, both men and women, who have not trained their 
back extensors in isolation in the last 12 months. During a 6-week program consisting of a total 
of 12 sessions, the participants receive a diathermy treatment with the CE-certified device Tecar 
(T-Plus, Wintecare SA, Chiasso, Switzerland) and carry out a back extensor resistance training 
on the CE-certified ILEX machine Myosom (Heftec GmbH, Oberurnen, Switzerland).  
 
Participants are randomly assigned to either the sham group, which receive a 10-minute 
treatment with the diathermy device turned off and not sending radiofrequency before each 
exercise session, or the intervention group, which undergo a 10-minute diathermy treatment to 
induce 448kHz capacitive monopolar radiofrequency and facilitate warming up of deep tissues. 
After all treatments participants are asked to rate their thermal sensation and comfort.  
 
After the 10-minute diathermy treatment, the participants are seated in the ILEX machine in a 
semi-seated position with the feet placed on a footrest. The lumbar back is leaning against a 
round restraint that is free to rotate on its axis, the thoracal back against a squared restraint, 
hosting the load cells measuring torques produced by the left and right side separately. The 
machine incorporates a counterweighting procedure to counterbalance the effect of gravity 
acting on the upper body. Restraining belts are secured around the pelvis and around both 
shoulders. Over the anterior part of the upper thigh a restraint pad is positioned. All restraints 

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are tightened until a pressure but not pain occurs. These restraints prevent unwanted vertical 
movement of the pelvis or thighs. 
 
Training will take place twice a week, beginning with a dynamic warm-up of the lumbar extensor 
for 120s, followed by three sets of resistance training lasting 120s, 120s, and 150s respectively, 
and concluding with a final set of dynamic recovery lasting 60s. 30-second recovery will be 
provided between every set. A low load will be used for the warm-up and recovery. The initial 
load is based on the maximum isometric force and subsequently increased until volitional 
fatigue. Repetitions will be executed by taking three seconds from complete flexion to complete 
extension, ensuring standardization at 20 repetitions per minute. A metronome with 40 beats 
per minute will provide audible feedback. The ILEX machine emits an audible signal upon 
completion of each phase of the repetition to guarantee a complete range of motion (ROM) is 
achieved. Subsequent to every training session, participants will be requested to provide their 
effort (RPE-E) and discomfort (RPE-D) values. 
 
Baseline (BL) measurements are conducted before the initiation of training, and two follow-up 
measurements (F/U 1 and F/U 2) carried out after the sixth and twelfth session, with a minimum 
break of 48 hours after the last training session to ensure proper recovery and to prevent 
inaccuracies in muscle thickness measurement arising due to acute edema. At BL, participants 
need to give written informed consent and be familiarized with the ILEX machine and Category-
Ratio-Scale (CR10) for the assessment of perceived effort and discomfort as well as a 9-point 
Likert scale for thermal sensation and 5-point scale for comfort. BL assessment include 
epidemiological data such as age, sex, height, and weight. Physical activity is assessed using 
the self-administered short German version of the International Physical Activity Questionnaire 
(IPAQ) with a “last 7 d recall” (IPAQ Research Committee, 2005) at BL, F/U1 and F/U2. At all 
three measurements (BL, F/U 1, F/U 2), the lumbar extensor musculature thickness (M. erector 
spinae), the maximum ROM, the maximum voluntary isometric contraction, the lower back 
flexibility, and the isometric back extension endurance are measured. Skin temperature is 
measured using an infrared thermal imaging (FLIR A615 series, Emitec Industrial, Rotkreuz, 
Switzerland) after the first and final diathermy treatment.  
 
4 
STUDY POPULATION AND STUDY PROCEDURES 
4.1 Inclusion and exclusion criteria, justification of study population 
Power analysis was conducted with G*power to determine participants numbers (n) calculating 
a treatment effect size of 0.46 from previous research with the comparable MedX ILEX device in 
healthy volunteers (Fisher et al., 2018). The priori sample size was calculated (α = 0.05; effect 
size = 0.46; test family = F test, and statistical test = analysis of variance (ANOVA) repeated 
measures, within-between interaction; number of groups = 2; number of measurements = 3; 
power = 0.8) and revealed n = 10 participants. 14 healthy volunteers will be recruited according 
to the following criteria:  
 
Study inclusion criteria:  
- 
Healthy (no acute musculoskeletal injuries or illness),  
- 
Pain free, 
- 
Sufficient understanding of the German language,  
- 
Able to give informed consent as documented by signature, 
- 
Between 18 and 50 years old 
 
Study exclusion criteria: 

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- 
Pregnant (urine pregnancy test is given to participating woman) or lactating women, 
- 
Medication, 
- 
Previous surgery in the lumbar spine, 
- 
Knee or hip disorders contraindicating the use of ILEX device, 
- 
Currently experiencing LBP, 
- 
History of LBP or lumbar spine pathologies or known deformities, 
- 
Psychological or neuromuscular disorders, spinal pathologies or any other injuries or 
illness that would restrict normal movement, 
- 
Previous (last 12 months) or current isolated training of the lumbar extensor. 
 
This study will be conducted in healthy people. The risk of injury will be low in this population 
group.  
 
4.2 Recruitment, screening and informed consent procedure 
Participants will be recruited on the websites of the physiotherapy schools Thim van der Laan 
(www.physioschule.ch) and University of Applied Sciences of Southern Switzerland SUPSI 
(www.supsi-landquart.ch). An electronic advertisement will be activated on the screens in the 
building of the Thim van der Laan AG in Landquart. The advertisement texts are in line with the 
guidelines published by the Zurich Cantonal Ethics Committee.  
During the initial contact, potential participants are informed about the procedure and risks of 
the study, as well as the conditions and the amount of compensation. A checklist is used as the 
basis for telephone contact. During the first telephone contact, a questionnaire will be 
completed by the investigator to assess suitability for participation in the study. 
The investigators will explain to each participant the nature of the study, its purpose, the 
procedures involved, the expected duration, the potential risks and benefits and any discomfort it 
may entail. Each participant will be informed that the participation in the study is voluntary and 
that he or she may withdraw from the study at any time and that withdrawal of consent will not 
affect his or her subsequent medical assistance and treatment.  
The participant will be informed that his or her medical records may be examined by authorised 
individuals other than their treating physician. 
All participants for the study will be provided a participant information sheet and a consent form 
describing the study and providing sufficient information for participant to make an informed 
decision about their participation in the study. Enough time will be given to the participant to read 
the written informed consent at home, ask questions to the responsible examiner and decide 
whether to participate or not.  
The formal consent of a participant, using the approved consent form, will be obtained before the 
participant is submitted to any study procedure.   
The consent form will be signed and dated by the investigator or his designee at the same time 
as the participant sign. A copy of the signed informed consent will be given to the study participant. 
The consent form will be retained as part of the study records. The original signed informed 
consent form will be stored as a study document in a locked filing cabinet.  
Upon successful completion of the training sessions and the 3 test days, the participants are 
receiving a remuneration of 200 Swiss Francs.   
The advertisements, questionnaire, and checklist for the first contact can be found in the 
enclosure. 
4.3 Study procedures 
A table listing all study visits, relevant procedures, as well as all timelines, can be found in 

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appendix 1. 
12 sessions of back extensor resistance training on the ILEX machine take place over a 6-week 
period (twice a week). Before each exercise, a diathermy treatment is taking place. Before, after 
6 sessions and after completion of the 12 sessions, tests are conducted on separate days.  
On intervention days, the participants enter the RES laboratory in Landquart wearing sports 
clothing. First, they lay on an examination table in a prone position receiving a treatment with the 
diathermy device for 10 minutes from a trained examiner. The intervention group is treated with 
the diathermy device inducing 448kHz capacitive monopolar radiofrequency, warming up the 
deep tissues. The sham group receives a massage with the diathermy device without 
radiofrequency. Directly after the first and last diathermy treatment, a picture will be taken with an 
infrared camera (FLIR A600 series, Emitec Industrial, Rotkreuz, Switzerland). Then, participants 
translocate to the ILEX machine and are seated according to their individual settings. The training 
session lasts 12 minutes. Participants begin the training session with a dynamic warm-up of the 
lumbar extensor for 120s, followed by three sets of resistance training lasting 120s, 120s, and 
150s respectively, and concluding with a final set of dynamic recovery lasting 60s. Between each 
set, a 30-second recovery is provided. Repetitions will be executed by taking three seconds from 
complete flexion to complete extension, ensuring standardization at 20 repetitions per minute. A 
metronome with 40 beats per minute will provide audible feedback. The ILEX machine emits an 
audible signal upon completion of each phase of the repetition to guarantee a complete ROM is 
achieved. A low load is used for the warm-up and recovery. For the three training sets, the initial 
load is based on the maximal isometric force and subsequently increased until volitional fatigue. 
Immediately subsequent to each training session, participants will be requested to provide their 
effort (RPE-E) and discomfort (RPE-D) values. Immediately after the first and final diathermy 
treatment before dislocating to the ILEX machine, participants skin temperature is measured while 
laying prone on the examination table making an imaging with the FLIR camera.  
On the examination days (BL, F/U1 and F/U2), the participants enter the RES laboratory in 
Landquart wearing sports clothing. At baseline, participants are asked to sign an informed consent 
form and are screened for inclusion and exclusion criteria. Participants are then asked for their 
age and sex, height is measured using a stadiometer (GPM Stadiometer, Zurich, Switzerland), 
and weight and lower body fat percentage are measured using a scale (TANITA-TBF 611 scale, 
Tokyo, Japan). At all three measurements (BL, F/U1 and F/U2) participants are asked to complete 
the IPAQ to assess physical activity. Next participants are placed on the examination table in a 
prone position for an ultrasound scan to measure the thickness of the M. erector spinae on the 
right side. The probe head is coated with coupling gel and applied perpendicular to the muscle 
on the right side without pressure to not compress the dermal surface. The images are saved, 
and the distance is measured later. Participants are then familiarised with the ILEX machine and 
positioned for individual adjustments. After a warmup for 120s with a low load and a short break, 
participants are asked to move dynamically into full flexion and full extension over the full ROM 
for three times. The test is repeated a second time. After a 2-minutes break, participants are asked 
to slowly move backwards to maximal tension and repeat the isometric force test after 2-minutes 
break. Next, the participant is seated in front of the sit-and-reach test box keeping the knees fully 
extended and the feet dorsiflexed against the foot-support. The participant is moving actively, 
slowly forward, bringing the body to the pain-free limit. The participant's hands move along the 
scale on the block until the movement is terminated because the participant can go no farther. 
The final position is held with an isometric contraction for 2 seconds, and the distance is read on 
the scale. After a 2-minutes break, the test is repeated. The rating scales for perceived effort, 
discomfort and thermal sensation are then presented for familiarization. Finally, the isometric back 
extension endurance is measured through the Biering-Sørrensen test. The participant is lying 
prone on an examination table with the upper border of the iliac crests in line with the edge of the 
table. The lower body is secured to the table by three straps around the pelvis, knees, and ankles. 
With the arms folded across the chest, the participant is asked to hold the upper body isometrically 
in a horizontal position. A stopwatch is used to measure the time the participant can keep the 
unsupported upper body in contact with a horizontal object. The examination takes about 1 hour.  

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Withdrawal and discontinuation 
Participants can withdraw from the study at any time without giving a reason. Previous research 
has shown that training the back extensor muscles with ILEX machines once a week is as 
effective as training two or three times a week for increasing isometric lumbar extension strength 
(Carpenter et al., 1991; Graves et al., 1990). Missed training sessions are analysed on a case-
by-case basis to decide whether to withdraw from the study. Participants will be withdrawn from 
the study if an impending injury or illness contraindicates the use of the ILEX device. For scientific 
and economic reasons, data already collected are included in the analyses as far as possible. 
5 
STATISTICS AND METHODOLOGY 
5.1. Statistical analysis plan and sample size calculation 
A priori sample size calculation was performed using G*power (Version 3.1, Franz Faul, Germany) 
to determine participants numbers (n) (α = 0.05; effect size = 0.46; test family = F test, and 
statistical test = analysis of variance (ANOVA) repeated measures, within-between interaction; 
number of groups = 2; number of measurements = 3; power = 0.8) and revealed n = 10 
participants. The effect size was estimated based on previous research with a comparable ILEX 
device in healthy volunteers (Fisher et al., 2018).  
Assumption of normality will be verified using the Shapiro-Wilk test. Mauchly’s test will indicate 
the violation of the assumption of sphericity. Normally distributed data will be analysed applying 
ANOVA repeated measures with within-between interactions to compare the means of each 
variable over the three repeated observations (within) and between the intervention and sham 
group (between). Not normally distributed data will be examined using non-parametric statistics 
(Friedman’s two-way ANOVA). Post hoc Bonferroni test correction will be applied. Probability 
values p < 0.05 will be considered statistically significant. 
Men and women are included in this study and will be part of the randomization process. The 
planned sample size of this study does not allow for gender-specific analysis. A gender difference 
analysis will have to be part of a future study.  
Analyses will be performed using RStudio Team (2023) (RStudio: Integrated Development 
Environment for R. Boston, MA) and IBM SPSS Statistics (Version 27, IBM Corp., Armonk, NY, 
USA).  
5.2. Handling of missing data and drop-outs 
Missing data, missed training sessions or discontinuation are recorded on the CRF. Data from 
patients who drop out are achieved and stored. Drop-outs are not replaced by recruitment of new 
participant. If consent is withdrawn, the data already collected are included in the analysis for 
scientific and safety reasons. These are only anonymised after the analysis (Art. 9 ClinO). 
6 
REGULATORY ASPECTS AND SAFETY 
6.1 Local regulations / Declaration of Helsinki 
This study is conducted in compliance with the protocol, the current version of the Declaration of 
Helsinki, the ICH-GCP, the HRA as well as other locally relevant legal and regulatory 
requirements.  
6.2 (Serious) Adverse Events and notification of safety and protective measures 
An Adverse Event (AE) is any untoward medical occurrence in a patient or a clinical investigation 
subject which does not necessarily have a causal relationship with the trial procedure. An AE can 

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therefore be any unfavourable or unintended finding, symptom, or disease temporally associated 
with a trial procedure, whether or not related to it. 
 
A Serious Adverse Event (SAE) (ClinO, Art. 63) is any untoward medical occurrence that 
- 
Results in death or is life-threatening, 
- 
Requires in-patient hospitalisation or prolongation of existing hospitalisation, 
- 
Results in persistent or significant disability or incapacity, or 
- 
Causes a congenital anomaly or birth defect  
 
Both Investigator and Sponsor-Investigator make a causality assessment of the event to the trial 
intervention, (see table below based on the terms given in ICH E2A guidelines). Any event 
assessed as possibly, probably or definitely related is classified as related to the trial intervention. 
 
Relationship 
Description 
Definitely 
Temporal relationship 
Improvement after dechallenge* 
Recurrence after rechallenge 
(or other proof of drug cause) 
Probably 
Temporal relationship 
Improvement after dechallenge 
No other cause evident 
Possibly 
Temporal relationship 
Other cause possible 
Unlikely 
Any assessable reaction that does not fulfil the above conditions 
Not related 
Causal relationship can be ruled out 
*Improvement after dechallenge only taken into consideration, if applicable to reaction 
 
Both Investigator and Sponsor-Investigator make a severity assessment of the event as mild, 
moderate or severe. Mild means the complication is tolerable, moderate means it interferes with 
daily activities and severe means it renders daily activities impossible.  
 
No (serious) Adverse Events are expected.  
 
Reporting of SAEs (see ClinO, Art. 63) 
All SAEs are documented and reported immediately (within a maximum of 24 hours) to the 
Sponsor-Investigator of the study. 
If it cannot be excluded that the SAE occurring in Switzerland is attributable to the intervention 
under investigation, the Investigator reports it to the Ethics Committee via BASEC within 15 days. 
 
Follow up of (Serious) Adverse Events 
Not applicable, no SAE are expected in this study design.  
  
Notification of safety and protective measures (see ClinO, Art 62, b) 
If immediate safety and protective measures have to be taken during the conduct of the study, 
the investigator notifies the Ethics committee of these measures, and of the circumstances 
necessitating them, within 7 days. 

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6.3 (Periodic) safety reporting 
An annual safety report (ASR) is submitted once a year to the local Ethics Committee by the 
Investigator (ClinO, Art. 43 Abs 1). 
6.4 Radiation 
The radiofrequency electromagnetic field caused by the diathermy device induces 448kHz 
capacitive monopolar radiation. This electromagnetic energy generates heat by oscillation and 
friction of charged molecules (Guy et al., 1974). Ultrasound is using high-frequency sound 
waves and not ionizing radiation to capture images like X-ray imaging. Therefore, no hazardous 
radiation is used in this study.  
6.5 Pregnancy  
Pregnant or breastfeeding woman are excluded from participating in the study. A urine 
pregnancy test is given to the women together with the participant information. The negative 
test result must be presented on the first examination day. In the event of a positive test, women 
will be asked to report this by telephone and will not be included in the study.  
No risks regarding contraception of any kind are to be expected; to date, no such risks are 
known for this procedure. Participants who become pregnant during the study must inform their 
investigator immediately and may not continue to participate in the study.  
6.6 Amendments 
Substantial changes to the study setup, organization, protocol and related study documents will 
be submitted to the Ethics Committee for approval prior to implementation.  
Under emergency circumstances, deviations from the protocol to protect the rights, safety and 
well-being of human subjects will be documented and reported to the Ethics Committee as soon 
as possible. 
6.7 Notification and reporting upon completion, discontinuation or interruption of the 
study 
Upon regular study completion, the Ethics Committee is notified via BASEC within 90 days (ClinO, 
Art. 38).  
The Sponsor-Investigator may terminate the study prematurely according to certain 
circumstances, e.g. 
- 
Ethical concerns, 
- 
Insufficient participant recruitment, 
- 
When the safety of the participants is doubtful or at risk (e.g. when the benefit-risk 
assessment is no longer positive), 
- 
Alterations in accepted clinical practice that make the continuation of the study unwise, or 
- 
Early evidence of harm or benefit of the experimental intervention 
Upon premature study termination or study interruption, the Ethics Committee is notified via 
BASEC within 15 days (ClinO, Art. 38). 
A final report is submitted to the Ethics Committee via BASEC within a year after completion or 
discontinuation of the study, unless a longer period is specified in the protocol (ClinO, Art. 38). 
6.8 Insurance 
In the event of study-related damage or injuries, the liability of the institution Thim van der Laan 
AG provides compensation, except for claims that arise from misconduct or gross negligence.  

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7 
FURTHER ASPECTS 
7.1 Overall ethical considerations 
The study is being carried out on healthy volunteers. However, ILEX machines are also designed 
to provide a safe way for people with back problems to exercise. Therefore, training experience 
with ILEX machines will help not only healthy people, but also patients with back problems. In 
addition, heat therapy has the potential to support hypertrophy in resistance training. The results 
from the diathermy therapy will provide guidance for patients who are unable to examine 
resistance training to voluntary fatigue. Future studies in patients are planned to investigate the 
effect of training and preheating in relation to back problems.  
7.2 Risk-benefit assessment  
There are no health risks associated with participating in this study. The ILEX machine is CE-
certified and based on equipment that has already been tested. The product is used in accordance 
with the instructions for use. The training sessions take place at low load and with a slow increase 
in load, which means that there is a negligible risk of injury. It is possible that fatigue of the back 
muscles or slight muscle soreness limited to the back may occur as a result of the training.  
The use of diathermy therapies has been common practice for two decades. Treatment with the 
diathermy device is safe and most people find it very pleasant. Very sensitive skin may experience 
temporary redness and/or tingling. The tecar device is CE-certified and is used in accordance 
with the instructions for use.  
Participation in the study does not result in any direct benefits for the test person. Ideally, the test 
participants improve the strength of the back extension muscles. The results of the study will help 
future people with back pain to receive effective treatment.  
8 
QUALITY CONTROL AND DATA PROTECTION 
8.1 Quality measures  
For quality assurance the sponsor, the Ethics Committee or an independent trial monitor may visit 
the research sites. Direct access to the source data and all study related files is granted on such 
occasions. All involved parties keep the participant data strictly confidential.  
8.2 Data recording and source data 
For this study, all data will be reported in the paper CRF and translated into a Microsoft Excel 
file (Version 16.79 (2023), Microsoft Corporation, Redmond, Washington, USA). Maximum 
isometric force and ROM of the back extensor are both automatically saved in Microsoft Access 
(Version 6_4, Microsoft Corporation, Redmond, Washington, USA), translated to the CRF and 
exported to Microsoft Excel. The image of the M. erector spinae, generated through the 
ultrasound system Mylab2 (Esaote, Maastricht, Netherlands), is exported to the software 
HorosTM (Horos Project, Annapolis, MD, USA). The result of measuring the muscle thickness is 
reported on the CRF file and entered into Microsoft excel. Epidemiologic data, inclusion and 
exclusion criteria, measurements of the sit-and-reach test, Biering-Sørrensen test, ratings of 
perceived effort, discomfort, thermal sensation, and comfort, and details of each training 
session are recorded directly on the CRF and transferred to Microsoft Excel. 
8.3 Confidentiality and coding 
Trial and participant data will be handled with uttermost discretion and is only accessible to 
authorized personnel who require the data to fulfil their duties within the scope of the study. On 

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the CRFs and other study specific documents, participants are only identified by a unique 
participant number.  
The generated data are coded by a unique participant number. The Excel file is stored in Microsoft 
Teams classic (version 1.6.00.29954, Microsoft Corporation, Redmond, Washington, USA), 
which is accessible by the team of the Rehabilitation and Exercise Science Laboratory RESlab in 
Landquart with a password. The participation identification list is stored separately in Microsoft 
Teams in a password-protected area accessible only to the principal investigator of the study. 
Printed documents (CRF) are stored in a separate lockable filing cabinet. Only the principal 
investigator has the key to this cabinet. An automatic back-up of the Microsoft team takes place 
every night. 
8.4 Retention and destruction of study data and biological material 
All study data are archived for 10 after study termination or premature termination of the study. 
The generated data are transferred to a password-protected archive in Microsoft teams 
accessible for the RESLab team. The participation identification list is stored separately in 
Microsoft Teams in a password-protected area accessible only to the principal investigator of the 
study. Printed documents are stored in a separate lockable filing cabinet, only accessible for the 
principal investigator.  
 
9  MONITORING AND REGISTRATION 
The monitoring will be done by Dr. Ursula Hohenauer Küng from the institution THIM – Die 
internationale Hochschule für Physiotherapie, Weststrasse 8, 73002 Landquart.  
Dr. Küng will ensure that trial is conducted and documented properly by carrying out the 
following activities when relevant and necessary to the trial: 
- 
Verifying that the investigator has adequate qualifications and resources and remain 
adequate throughout the trial period, that facilities, including laboratories, equipment and 
staff, are adequate to safety and properly conduct the trial and remain adequate throughout 
the trial period. 
- 
Verifying for the study interventions: 
o That the intervention conditions are acceptable. 
o That the study interventions are supplied only to subjects who are eligible to receive 
it. 
o That subjects are provided with necessary instructions on the study interventions. 
- 
Verifying that the investigator follows the approved protocol and all approved amendments, 
if any. 
- 
Verifying that written informed consent was obtained before each subject participation in the 
trial. 
- 
Ensuring that the investigator and the investigator’s trial staff are adequately informed about 
the trial. 
- 
Verifying that the investigator is enrolling only eligible subjects. 
- 
Reporting the subject recruitment rate. 
- 
Verifying that the investigator provides all the required reports, notifications, applications, 
and submissions, and that these documents are accurate, complete, timely, legible, dated, 
and identify the trial. 
- 
Adverse events, concomitant medications and intercurrent illnesses are reported in 
accordance with the protocol on the CRFs 
- 
Visits that the subjects fail to make, tests that are not conducted and examinations that are 
not performed are clearly reported as such on the CRFs. 
- 
All withdrawals and dropouts of enrolled subjects from the trial are reported and explained 
on the CRFs. 
 

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This study will be registered on the Swiss National Clinical Trial Portal.  
10. FUNDING / PUBLICATION / DECLARATION OF INTEREST 
The Thim van der Laan AG, headed by Thim van der Laan Jr., is responsible for the 
management of a Bachelor’s degree course in physiotherapy for the University of Applied 
Sciences of Southern Switzerland (SUPSI), which includes a scientific research laboratory. The 
study is financed by the University of Applied Sciences of Southern Switzerland SUPSI. The 
sponsor is Thim van der Laan AG.  
 
The diathermy device is provided by Wintecare (Wintecare SA, Chiasso, Switzerland) and the 
ILEX machine by Heftec (Heftec GmbH, Oberurnen, Switzerland) for the duration of the study.  
 
The examiners ensure that the participant's privacy is guaranteed. In particular, data protection 
and confidentiality are guaranteed, and no personal data is presented or published or passed 
on to outsiders or unauthorised persons. Gender effects are analysed and published.  

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Appendix 1: Schedule of assessments 
 
Visit 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
Week 
1 
1 
2 
2 
3 
3 
4 
6 
6 
6 
7 
7 
8 
8 
10 
Time (hour) 
1 
½ 
 
½ 
 
½ 
 
½ 
 
½ 
 
½ 
 
1 
½ 
 
½ 
 
½ 
 
½ 
 
½ 
 
½ 
 
1 
Therapy and 
training 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Skin 
temperature 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Rating of 
perceived 
effort 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Rating of 
perceived 
discomfort 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Rating of 
thermal 
sensation 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Rating of 
perceived 
comfort 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Examination 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Maximal 
isometric 
force 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Maximal 
range of 
motion 
(ROM) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Sit-And-
Reach-Test 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Biering-
Sørensen 
test 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ultrasound 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Physical 
activity