Table 3 Constructs, assessment methods, parameters and data collection schedule

Physical functions

 Mobility and function of the lower extremities

Timed Up-and-Go Test¹

Time (s) to complete the task

X

X

X

 Functional exercise capacity and dynamic postural control

Six-minute walk test with inertial measurement units (IMUs) and an electro-cardiogram

Walking distance (m) in 6 min, gait kinematics (e.g. minimum toe clearance, gait variability) and heart rate

X

X

X

 Functional leg extensor muscle power

Five-repetition sit-to-stand test on a force plate

Time (s) and rate of force development

X

X

X

 Flexibility

Instrumented trunk range of motion assessment

Active range of motion (°)

X

X

X

Subjective health state

 Back pain associated disability in daily life

Oswestry Disability Index

Total score (0–100%)

X

X

X

 Health-related quality of life

EQ-5D-5L

Index value (−0.66 to 1) and subjective overall health state (0–100)

X

X

X

Motor-cognitive dual task performance

 Static and dynamic postural control during a cognitive challenge, haemodynamic response in the prefrontal cortex (PFC) and dual task costs

Single and dual task bipedal stance performance on a force plate (with and without closed eyes) as well as gait analysis with IMUs, functional near-infrared spectroscopy and finger oximeter

Deviation of the center of pressure (e.g. sway and velocity), gait kinematics (e.g. minimum toe clearance, gait variability, gait velocity), oxy- and deoxyhaemoglobin concentrations in the PFC, number of correct calculations and peripheral oxygenation

X

X

X

Executive functions

 Inhibitory control

Colour-Word-Interference Test

Time (s) and error rate

X

X

X

 Cognitive flexibility

Trail Making Test

Time (s) and error rate

X

X

X

Psychosocial aspects

 Fear of movement

Tampa Scale of Kinesiophobia

Total score (11–44)

X

X

X

 Pain coping strategies

Coping Strategies Questionnaire

Total score for each coping strategy (0–36)

X

X

X

Additional

 Sociodemographic data

Intake form

e.g. age, sex, education

X

 Physical characteristics

Intake form

e.g. height, weight

X

X

X

 Current pain intensity

Numerical rating scale

Score (0–10)

X

X

X

 Specific characteristic and treatment history of chronic pain

German Pain Questionnaire

Descriptive data, time period (months) of chronic pain, pain intensity (0–10) in the last 4 weeks

X

X

X

 Level of everyday activity

Freiburger Questionnaire on Physical Activity

Time (h) of physical activity in a week

X

X

X

 State fatigue

Fatigue subscale of the Profile of Mood States

Score (0–42)

X

X

X

 Depression

Beck Depression Inventory II

Total score (0–63)

X

X

X