Malaysia 
Validation Studies
Validation Studies
The DAVID equipment has been subjected to several validation studies. In this overview you will find the most relevant studies and a complete list of all studies conducted so far. Ongoing research is being conducted on the validation of our equipment. When the studies are published they will be included on this page.
Isometric reliability test
Objective
To investigate the reliability of mobility measurement and isometric strength measurement in David spine devices.
Method
Measurements were performed on three different days by an experienced tester. The time interval between each examination day was 72 hours. Tests were performed with David Spine devices.
Outcome
The isometric strength measurements showed a strong correlation (r=0.94-0.99). Also the correlation in mobility measurements (in those movement direction where it was measured) was strong (r=0.90-0.98).
Denner A. Muskuläre Profile der Wirbelsäule. Berlin, Heidelberg; Springer; 1997. Chapter 7.4, Ergebnisse Eigener Reliabilitäts- und Validitätsuntersuchungen; p. 163–178.
Muscle activity in target muscles in different movement directions of the spine
Objective
To analyze the muscle activity of the target muscles compared to other muscles in David Spine devices.
Methods
EMG was used to test the isolation of target muscles during maximal isometric contraction. In 110 and 130 devices also muscle activation during submaximal dynamic muscle work (70% of 1 RM) was tested.
Outcome
Fixation in David Spine devices seems to effectively activate target muscles and inhibit other muscles.
Denner A. Muskuläre Profile der Wirbelsäule. Berlin, Heidelberg; Springer; 1997. Chapter 7.4, Ergebnisse Eigener Reliabilitäts- und Validitätsuntersuchungen; p. 163–178.
Intra- and inter-tester reliability and reference values for isometric neck strength.
Objective
To determine intra- and inter-tester reliability and age- and sex-specific reference values for isometric neck strength in extension, flexion and lateral flexion in sitting position measured with David 140 device.
Methods
Reliability: Intra-tester reliability was studied in three repeated test trials, with 10 minutes of rest between the measurement series. Inter-tester reliability was studied by repeating the procedure with each of the three test leaders at the same time of the day, on three different occasions, with an interval of one week between test series.
Reference values: One maximal effort for about six to eight seconds was registered in each movement direction for each subject.
Outcome
Intra-tester reliability, for all three test leaders, expressed as the ICC value was 0.94–0.97 for neck strength in extension, flexion, lateral flexion (right/left). Inter-tester reliability among the three test leaders was 0.86–0.95 in the four directions. For all three test leaders, and for almost all directions, measurement one was found to have the highest value. Results show that Intra- and inter-tester reliability of the 140 was very good to excellent.
Peolsson A, ÖBerg B, Hedlund R. Intra- and inter-tester reliability and reference values for isometric neck strength. Physiotherapy Research International 2001;6(1):15-26.
Overview validation studies:
- Häkkinen K, et al. Scientific Evaluation of Specific Loading of the Knee Extensors with Variable Resistance, ‘Isokinetic’ and Barbell Exercises. Med Sport Sci. 1987;26:224-237.
- Häkkinen K, et al. Effects of fatiguing loading with a variable resistance equipment on neural activation and force production of the knee extensor muscles. Electromyogr Clin Neurophysiol. 1988;28(2-3):79-87.
- Denner A. Muskuläre Profile der Wirbelsäule. Berlin, Heidelberg; Springer; 1997. Chapter 7.4, Ergebnisse Eigener Reliabilitäts- und Validitätsuntersuchungen; p. 163–178.
- Denner A. Muskuläre Profile der Wirbelsäule. Berlin, Heidelberg; Springer; 1997. Chapter 7.4, Ergebnisse Eigener Reliabilitäts- und Validitätsuntersuchungen; p. 163–178.
- Kankaanpää M, et al. Lumbar paraspinal muscle fatigability in repetitive isoinertial loading: EMG spectral indices, Borg scale and endurance time. European Journal of Applied Physiology 1997;76(3):236-242.
- Kankaanpää M, et al. Reference change limits of the paraspinal spectral EMG in evaluation of low back pain rehabilitation. Pathophysiology 1998;5(3):217-224.
- Kankaanpää M, et al. Back and hip extensor fatigability in chronic low back pain patients and controls. Archives of Physical Medicine and Rehabilitation 1998;79(4):412-417.
- Taimela S, et al. A submaximal back extension endurance test utilising subjective perception of low back fatigue. Scandinavian Journal of Rehabilitation Medicine 1998;30(2):107-112
- Peolsson A, et al. Intra- and inter-tester reliability and reference values for isometric neck strength. Physiotherapy Research International 2001;6(1):15-26.
- Leinonen V, et al. Impaired Lumbar Movement Perception in Association With Postural Stability and Motor- and Somatosensory-Evoked Potentials in Lumbar Spinal Stenosis. Spine 2002;27(9):975-983.
- Elfving B. Lumbar muscle fatigue and recovery: Evaluation of electromyography in patients with long-term low-back pain and in healthy subjects. Karolinska Institutet. Doctoral Dissertation; 2002.
- Walker S, et al. Kinetic and electromyographic analysis of single repetition constant and variable resistance leg press actions. Journal of Electromyography and Kinesiology 2011;21(2):262-269
- Peltonen H, et al. Neuromuscular responses to different resistance loading protocols using pneumatic and weight stack devices. Journal of Electromyography and Kinesiology 2013;23(1):118-124.
- Kienbacher T, et al. Reliability of isometric trunk moment measurements in healthy persons over 50 years of age. Journal of Rehabilitation Medicine 2014;46(3):241-249.