The longissimus dorsi network - the backup of posture and motion

About 85% of Central Europe`s population suffer at least once during their lifetime of back pain, often of musculogenic origin. This frequent disease causes enormous financial loss, mainly in the form of therapy costs and sickness related absenteeism. The long back muscle (LBM) is a main protagonist in the spinal stability. Through its branched anatomical structure and complex function it is a multifaceted network sensitive to functional disorders. The complexity of the muscle makes it difficult to clarify the physiological mechanisms and the pathological responses to disease-related disorders. The aim of this project is to study the behavior of the long back muscle, a major muscle network in the backs of horses and humans, and to show whether data exchange between the two species may be useful. For this purpose, the function of the long dorsal muscle of humans and horses should be examined. The advantages of using horses are that they are readily available, cooperative (easy to handle) and that their muscles are relatively large compared to those of humans. This fact allows placing more electromyographic (EMG) electrodes on the long back muscles of horses than in humans. As first step the function of the LBM of 15 healthy humans and 15 healthy horses will be documented using a kinematic camera system combined with a synchronized EMG. An anatomy based mechanical model of each muscle network (human and horse) will be created, transformed into its electrical equivalent and then analyzed with the electrical engineering network tools available. In addition the behaviour of the LBM in patients with increased kyphosis (sagittal profile of> 50 ) and horses with side reins (Rollkur) will be compared. Expected results: Based on the network theory a method for analyzing muscle networks should be developed. These special network facilities are expected to support an easy data exchange between the two species. The project should show the coordination within a muscle network and how pain or pathological processes will interfere and influence the interaction within the muscle network and what the resulting long-term consequences (overload, disease) will be. In addition, findings in horses will be transformed/related to those in humans. This can be of practical as horses have a very large LBM compared to humans and therefore allow more detailed analysis of the muscle networks. Equine orthopedics will also benefit from these results.

About 85% of Central Europe`s population suffer at least once during their lifetime of back pain, often of musculogenic origin. This frequent disease causes enormous financial loss, mainly in the form of therapy costs and sickness related absenteeism. The long back muscle (LBM) is a main protagonist in the spinal stability. Through its branched anatomical structure and complex function it is a multifaceted network sensitive to functional disorders. The complexity of the muscle makes it difficult to clarify the physiological mechanisms and the pathological responses to disease-related disorders. The aim of this project was to study the behavior of the long back muscle, a major muscle network in the backs of horses and humans, and to show whether data exchange between the two species may be useful. For this purpose, the function of the long dorsal muscle of humans and horses was examined. Based on 5 horses the anatomy of the long back muscle was studied and a model developed. In the next step, the movements and the activity of the long back muscle of 15 horses were analysed using a kinematic- (18 cameras) and a synchronised surface electromyography (EMG) system and related to the data of the humans (15 healthy and 5 patients with an increased kyphosis (sagittal profile> 50 )). We could show that the results from the horse can be transferred to those of humans. The activity of the long back muscle is very similar in walking humans and trotting horses. Therefore the horse is an adequate model for humans to study the function of the long back muscle. Not surprisingly, because both walking man and trotting horse show a diagonal synchronism of the extremities. Human and horse models were used to simulate the muscle activity of the long back muscle and to compare the muscle networks. The foundation of the models facilitated the exchange of data between the two species and allowed the investigation of coordination within the muscle network e. g. how disorders will change the interaction or what will be the consequence of overload or illness. Because of the horses` long back muscles, which are very large compared to humans, more detailed muscle analyzes were possible, which could be transferred to humans. Of course, this knowledge can also benefit veterinary orthopedics.