Improvement Through Movement - Balance Control and Somatosensory Function in People With Diabetes Mellitus Type 2

Standing balance is measured with four modified Romberg conditions of increasing difficulty, each performed with eyes open and eyes closed. Each position is held as long as possible up to 30 seconds. Timing starts once a steady stance is achieved and stops at loss of position or at 30 seconds. Three trials are permitted per condition and the best trial counts. Scores from all eight conditions are summed to a total score ranging from 0 to 240 seconds.

Dynamic balance is assessed with the Timed Up and Go test using a standardized protocol, in which participants rise from a chair, walk three metres, turn, return and sit down. The time needed to complete the test is recorded in seconds. The test is performed in three trials and the best performance is retained.

Dynamic balance is assessed with a tandem gait test in which participants attempt 20 consecutive heel to toe steps along a straight tape line. The test ends at 20 steps or at violation of the test guidelines. The score is the number of correctly performed steps, ranging from 0 to 20, and is obtained in three trials with the best performance retained.

Balance control is assessed with the Mini Balance Evaluation Systems Test, a 14 item performance based test covering anticipatory postural adjustments, reactive postural control, sensory orientation and dynamic gait. Each item is scored from 0 to 2, giving a total score ranging from 0 to 28, with higher scores indicating better balance control.

Touch pressure thresholds are assessed with Semmes Weinstein monofilaments using the 4-2-1 stepping algorithm. A set of 20 logarithmically ordered filaments is applied and at each step the same filament delivers five stimuli. Testing covers six foot sites across plantar and dorsal regions and the threshold is reported per site as the filament scale value.

Vibration thresholds are assessed with a Howell neurothesiometer. Vibration at 56 Hz is delivered while the voltage increases from 0 to 50 volts and the participant signals when vibration is first perceived. That voltage is recorded as the vibration detection threshold, with lower values indicating better vibration sense.

Vibration sense is assessed with a 128 Hz Rydel Seiffer tuning fork. The fork is struck maximally and placed on standardized reference points until the vibration fades, and the participant signals when it is no longer felt. The result is read from the 0 to 8 scale of the fork, with higher scores indicating better vibration sense.

Habitual physical activity is assessed with the International Physical Activity Questionnaire Short Form, a self reported questionnaire covering the preceding seven days. Participants report the number of days on which vigorous activity, moderate activity and walking were performed, counting only bouts of at least ten minutes. The frequency is reported separately for each of the three domains and expressed in days per week, with a possible range of 0 to 7 days.

Habitual physical activity is assessed with the International Physical Activity Questionnaire Short Form, a self reported questionnaire covering the preceding seven days. Participants report the usual duration of vigorous activity, moderate activity and walking on the days these were performed, counting only bouts of at least ten minutes. Durations reported in hours and minutes are converted to minutes and multiplied by the number of days per week, giving the total weekly duration for each of the three domains, expressed in minutes per week and reported separately per domain.

Sedentary behaviour is assessed with the International Physical Activity Questionnaire Short Form as the time spent sitting on a typical weekday during the preceding seven days, including sitting at work, at home, while studying and during leisure time, and excluding time spent sleeping. Participants report this in hours and minutes, which are converted into a single value expressed in minutes per day.

Objective physical activity is monitored with the Garmin Vivosmart 5 worn on the wrist continuously throughout the monitoring period and removed only for charging. The device estimates total daily energy expenditure from accelerometry and heart rate data, combining resting and activity related expenditure. Values are averaged across all valid recording days, defined as days with sufficient wear time, to arrive at a single value expressed in kilocalories per day.

The same wrist worn activity tracker records heart rate continuously by optical sensor throughout the monitoring period. Recorded values are averaged across all valid recording days, defined as days with sufficient wear time, to arrive at a single value expressed in beats per minute.

The Garmin vivosmart 5 activity tracker registers daily step counts that are averaged across all valid recording days, defined as days with sufficient wear time, to arrive at a single value expressed in steps per day

Activities-Specific Balance Confidence Scale (ABC scale) describes 16 activities that the participant has to score from 0 to 100%, meaning having no confidence in not losing balance when performing the activity to having maximal confidence. A total score of 1600 can be obtained and will be calculated to a score of 100%, in which a score <50% indicates low levels of functioning, 50-80% indicates a moderate level of functioning and a score of >80% means the subject has a high level of functioning.

Symptoms of anxiety are assessed with the anxiety subscale of the Hospital Anxiety and Depression Scale, a self reported questionnaire covering the preceding week and excluding physical symptoms. The subscale consists of 7 items, each scored from 0 to 3, giving a total score ranging from 0 to 21. Higher scores indicate more symptoms of anxiety.

Symptoms of depression are assessed with the depression subscale of the Hospital Anxiety and Depression Scale, a self reported questionnaire covering the preceding week and excluding physical symptoms. The subscale consists of 7 items, each scored from 0 to 3, giving a total score ranging from 0 to 21. Higher scores indicate more symptoms of depression.

Body weight is measured with a digital scale to the nearest 0.1 kilogram and body height is measured with the participant standing against a wall. Both measurements are combined to calculate body mass index as weight divided by height squared, expressed in kilograms per square metre (kg/m^2).

Glycated haemoglobin is obtained by blood sampling or retrieved from the electronic health record, and reflects average blood glucose concentration over the preceding two to three month, expressed in %.