Movement strategies and thoracic range of motion during dynamic mobilisation exercises

Dynamic mobilisation exercises (DME) have been shown to increase multifidus size and symmetry. Chin between fetlocks DME, resulting in flexion of the cervical and thoracic spinal regions, has been shown to have a short-term thoracic flexion effect of an hour. In clinical practice the movement strategies used by the horse to reach the food bait during flexion DME are seen to vary, which may affect efficacy. This study aimed to investigate the relationship between movement strategies and thoracic range of motion (ROM) in horses repeating chin between fetlock DME. Twelve horses (14.3±4.1 yr) with no history of back pain were videoed repeating chin between fetlocks DME nine times. Markers were placed on withers, lowest dorsal spinal point and T18 and change of thoracic angle measured with 2D kinematic analysis software. Movement strategies were categorised, frequency of occurrence recorded and association of movement strategy to ROM assessed with Spearman’s rho. The four highest frequency movement strategies observed were horses moving their trunks caudally (86.1%), carpal flexion ipsilateral to the handler (72.2%), wither lowering (55.6%) and stepping backwards (33.3%). The median thoracic flexion ROM was 15.1° (IQR 11.8-16.2°) and there was a significant negative association between ROM and movement strategies (rs(36)=-0.462, P<0.005). Horses with more movement strategies, such as carpal flexion, had less thoracic flexion ROM. Altered movement strategies may be a method of the horse reaching the bait without achieving the desired thoracic flexion. Therefore, identifying the cause of these strategies and assessment of clinical impact is recommended.Acute effect of an elastic resistance band system on vertical movement symmetry in riding horsesE. Persson-Sjödin1, A. Byström1, A. Pedersen2, M. Johansson2, E. Smidt2 and A. Bergh21Swedish University of Agricultural Sciences, Department of Anatomy, Physiology and Biochemistry, Box 7011, 75007 Uppsala, Sweden, 2Swedish University of Agricultural Sciences, Department of Clinical Sciences, Box 7054, 75007 Uppsala, Sweden; [email protected] horses, back pain is a reason for reduced physical performance. The use of an elastic resistance band system claims to increase the activity and movement symmetry of the equine hind limbs and improve core stability. The aim of this randomised crossover study was to compare vertical movement symmetry of the head and pelvis with the elastic bands, with a girth, and without gear. Seven healthy horses, the majority with mild vertical movement asymmetry, were measured in trot during lunging and on straight line, using an inertial measurement unit system. Data were analysed in mixed models. Significance level was set to P<0.05. Elastic bands increased asymmetry of pelvic maximal (PDmax) position compared to without gear (+1.4 mm, P<0.001) and girth (+1.5 mm, P<0.001), respectively, on straight line but not during lunging. Girth had small, inconsistent effects during lunging only (0.4-0.7 mm, P=0.007-0.002). The results indicate that the elastic resistance band system may cause a small acute increase in vertical movement asymmetry, but the clinical significance of this is uncertain as it was not investigated if this effect is long-term consistent. Further studies are need to determine the effect of longer use of elastic resistance bands on the symmetry of horses.