Biomedical subjects

C Peham

Publications and source records attributed to C Peham.

25 records · Page 2Linked to original sources

PubMed1999

Limb locomotion--speed distribution analysis as a new method for stance phase detection.

The stance phase is used for the determination of many parameters in motion analysis. In this technical note the authors present a new kinematical method for determination of stance phase. From the high-speed video data, the speed distribution of the horizontal motion of the distal limb is calculated. The speed with the maximum occurrence within the motion cycle defines the stance phase, and this speed is used as threshold for beginning and end of the stance phase. In seven horses the results obtained with the presented method were compared to synchronous stance phase determination using a force plate integrated in a hard track. The mean difference between the results was 10.8 ms, equalling 1.44% of mean stance phase duration. As a test, the presented method was applied to a horse trotting on the treadmill, and to a human walking on concrete. This article describes an easy and safe method for stance phase determination in continuous kinematic data and proves the reliability of the method by comparing it to kinetic stance phase detection. This method may be applied in several species and all gaits, on the treadmill and on firm ground.

Animals↗

PubMed1999

Supporting forelimb lameness: clinical judgement vs. computerised symmetry measurement.

The aim of this study was to compare supporting forelimb lameness determined by a motion analysis system with the subjective grading of a trained equine orthopaedic surgeon. Trotting on a treadmill, 29 individuals with a supporting forelimb lameness were measured with the SELSPOT II system and judged by the clinician. The vertical motion of the head was measured, analysed using Fourier transform, and the percentages of symmetry determined. The veterinarian evaluated the lameness and graded it according to a clinical routine. Veterinarian and system for motion analysis assigned the lameness to the same leg in all cases, but the grading of the lameness differed in 6 out of 29 cases. The results of this study indicate that motion analysis can be used as an informative tool supporting the subjective veterinary judgement.

Animals↗

PubMed1999

Sedation and antisedation as tools in equine lameness examination.

A kinematic study was performed to establish the locomotion pattern of horses under detomidine sedation and the effects of antagonization for possible use during lameness examinations in uncooperative horses. The kinematics of 17 Warmblood horses (9 sound, 8 lame with chronic forelimb lameness) were recorded on 2 days using a high-speed video system while trotting (3.9 m/s) on a treadmill. On each day a control measurement was carried out prior to sedation with detomidine (10 micrograms/kg bwt) and repeated recordings at 15, 25, 35, 45 and 60 min after sedation. On the second day, sedation was antagonized using atipamezole (100 micrograms/kg bwt) after the 15 min recording. Head height and pulse rate documented the level of sedation. The head dropped from mean 1.23 m (s.d. 0.13) to 0.50 m (0.26) following sedation to reach again 1.06 m (0.19) after 60 min. Antagonization reversed the height significantly at the 25 min recording to 1.06 m (0.11). Walking and trotting were possible in all sedated horses in response to voice commands only. Forelimb lameness symmetry parameter (Head Acceleration Asymmetry: HAAS) in 8 lame horses did not change significantly due to sedation. Stride length increased significantly from mean 2.53 m (0.18) to 2.66 m (0.20) 15 min after sedation and reversed to 2.56 (0.17) m after antagonization. Stride and stance durations changed accordingly. In conclusion, sedation did not change the degree of lameness, but did alter the general locomotion pattern. Antagonization diminished most of these effects, but small differences to the unsedated pattern remained.

Adrenergic alpha-Agonists↗

PubMed1998

Speed dependency of motion pattern consistency.

Treadmills are widely used in equine motion analysis. For the evaluation of the trot of a horse, a trotting speed with low variation between motion cycles is necessary to make the measurements reproducible. The aim of this study is to show how an individual 'optimum' trotting speed for lameness quantification can be determined. In this study, the stability of a horse's gait pattern was evaluated by calculating the standard deviation (S.D.) of motion-cycle speed (MCS). In trot, eighteen horses were analysed at several speeds. The measurements were taken with the ExpertVision System (Motion Analysis Corporation) every 3 km h(-1) (= 0.83 m s(-1)), from the lowest to the highest individual trotting speed. At the different speeds the S.D. of MCS and the asymmetry of the vertical head motion were compared. At the speed where standard deviation was minimum, motion asymmetry was maximum. In twelve horses this optimum speed was situated in the middle of the individual trotting speed range, and in six horses the optimum speed was the maximum speed. The method presented in this study allows the determination of an optimum trotting speed and so contributes to precision and consistency of equine lameness analysis.

Animals↗

PubMed1998

An objective method for evaluating the flexibility of the back of standing horses.

The spinal movements in maximum arching, dipping and left and right lateral flexion were measured in 10 horses without signs of back pain. A system for motion analysis (Expert Vision System) was used to identify the position of the markers placed on the head, the spinous processes of T5, T10, T16, L3, and on 2 of the sacral spines. By definition, the maximum of the spinal movement was set when the T16 marker reached its maximum deviation from the start position. The difference between start position and maximum position was presented as per cent of the horse's height at the withers. At T16 the mean results for flexion (arching) of the back were 5.9% (s.d.0.9), for extension (dipping) -2.4% (s.d.0.7), for flexion to the left 4.2% (s.d.1.1), and for flexion to the right 5.3% (s.d.1.3).

Animals↗

PubMed1997

Compensatory movements of horses with a stance phase lameness.

In order to study the mechanism of lameness transfer from fore- and hindlimb lamenesses 2 hypotheses were investigated. Hypothesis 1: Horses with a true supporting limb lameness in one hindlimb show a false supporting limb lameness in the ipsilateral forelimb. Hypothesis 2: Horses with a true supporting limb lameness in one forelimb show a false supporting limb lameness in the contralateral hindlimb. Fourteen horses with fore- or hindlimb lameness were used for this study. Each horse was measured at the trot on a treadmill with standardised speed, before and after diagnostic blocks (9 horses), or with and without induced lameness (5 horses). The head acceleration asymmetry (HAAS) and the sacrum acceleration asymmetry (SAAS) were used for quantification of fore- and hindlimb lameness respectively. Changes were documented by changes of the HAAS or the SAAS. In all 4 horses with a true hindlimb lameness a synchronous false lameness of the ipsilateral forelimb was documented. In 6 of 10 horses with a forelimb lameness a lameness transfer could be assessed according to hypothesis 2. The results of this study show, that horses with a true severe lameness in the forelimb show a false lameness in the contralateral hindlimb, and horses with a true hindlimb lameness show a false lameness in the ipsilateral forelimb. This indicates that the location of the truly lame limb can be deduced from the distribution of 2 lamenesses on a sagittal or diagonal axis.

Acceleration↗

PubMed1996

A method of signal processing in motion analysis of the trotting horse.

The aim of this paper is to present a method of signal processing necessary for motion analysis in the trotting horse. Motion analysis is widely used to assess lameness in horses. By definition, lameness in trot is present if the movements during the stance phases of both fore or hind limbs differ. The motion of the horse is recorded using a system for motion analysis (Selcom, 1983, SELSPOT II User Manual, Pad Nr. 6710) and the vertical motion of the head during both stance phases is compared. The symmetry is analyzed comparing the values of the Fourier coefficients. Additional head movements are 'single events' and present a problem. In this article we propose a mode of data processing using a system matched filter that neglects the nonperiodic additional movements and allows calculation of the representative Fourier coefficients. In comparison with a filtering method previously used in motion analysis this method is proved to be advantageous, as the precision of symmetry comparison increases.

Animals↗