SOME NEUROMUSCULAR ASPECTS OF HUMAN MOVEMENTS AND THE CONSEQUENCES FOR THE MUSCULAR REHABILITATION

INTRODUCTION After a review. of training regimen normally used in sports and rehabilitation exercises the importance of the configuration of the stimuli with respect to the neuronal and muscular adaptations are discussed. Additionally it is important if rotatoric or translatoric movements are practiced and which type of muscle action is exercised: concentric, isometric, eccentric, stretch-shortening cycles with which contraction and movement velocity (for example isokinetic) or if combinations of the different possibilities are performed. METHODS The described investigations are based on dynamography, kinemetry, electro-myography, muscle biopsie techniques, computertomography, electrogoniometry and accelerometry as well as biochemical methods and others. RESULTS In training practice it is often believed that strength training merely calls for changes in enzymatic quantity or quality within the muscle which ultimately results in muscle cross-sectional increases. This can be true for different fiber types. Beside these effects the adaptation of the nervous system to the training stimulus plays an important role. Longitudinal studies on humans showed clear evidence that following a high intensity strength training there is an improvement in the ability to quickly mobilize greater innervations activities (faster recruitment, increases firing rate of motor units and more synchronized discharge of motoneurons). Another possibility for the improvement of the movement depends on the relation between excitatory and inhibitory mechanisms for one muscle for a specific movement. This can be shown very clearly in stretch-shortening cycles for inhibitory effects as well as for excitatory a. phenomena. Those inhibitory effects occur if the stretching load is to high. Consequently trained subjects are able to tolerate higher stretch loads. Same is true for unskilled and skilled persons. If subjects are fatigued or injured they also show a reduction of the EMG-pattern of the extensor muscles. In all described situations the inhibitory effects serve for a mrse regulation of the stiffness of the tendomuscular system in the initial ground contact. It is concluded that the inhibitory mechanisms are part of the dynamic performance dependent reaction, functionally serving as a protection system. A further way to improve movements results from better intermuscular coordination. lntermuscular coordination describes the ability of all muscles involved in a movement, agonists, antagonists and synergists, to cooperate wholly with respect to the aim of the movement. This type of adaptation is therefore movement specific and not transferable to another movement. CONCLUSIONS Based on the described results and con- siderations a model for neuromuscular rehabilitation is presented which involves a step-wise periodrsation of the training process. Especially movements which consist of stretch-shortening cycles must be a substantial part of the rehabilitation concept

COMPARISON OF DIFFERENT STRENGTH TRAININGS METHODS FOR THE DEVELOPMENT OF POWER

The purpose of this study was to identify the effect of three different training methods for increasing power output of the leg extension chain. Therefore three groups had to go through an eight week training program. One of the three groups had to perform counter movement jumps (CMJ) twice a week (group J) while the second group had to do two sessions with parallel squats every week. The third group (J + S) had to do the CMJs as well as the parallel squats twice a week. After the training period SJ and CMJ significantly increased in all experimental groups. No significant changes were found in the control group. Group J received an 8,8% increase in the SJ and an 8,9% increase in the CMJ while group S was able to enhance their jumping performance by 12,6% (SJ) and 11,8% (CMJ). Group J + S showed the biggest improvement by 15,5% in the SJ and 14,7% in the CMJ. The only significant difference between the three groups was found between group J and J + S in both testing conditions

Immediate effects after stochastic resonance whole-body vibration on physical performance on frail elderly for skilling-up training: a blind cross-over randomised pilot study.

Objective This pilot study examined the feasibility outcome recruitment, safety and compliance of the investigation for stochastic resonance whole-body vibration (SR-WBV) training. Another aim was to evaluate the effect size of one SR-WBV intervention session on Short Physical Performance Battery (SPPB), Expanded Timed Get Up-and-Go (ETGUG), isometric maximal voluntary contraction (IMVC) and rate of force development (IRFD) and chair rising (CR). Design Randomised double-blinded controlled cross-over pilot study. Method Feasibility outcomes included recruitment, safety and compliance. For secondary outcomes, SPPB, ETGUG, IMVC, IRFD and CR were measured before and 2-min after intervention. Nonparametric Rank-Order Tests of Puri and Sen L Statistics to Ranked Data were proposed. Wilcoxon signed-ranked tests were used to analyse the differences after SR-WBV intervention and sham intervention. Treatment effects between the interventions were compared by a Mann–Whitney U test. Results Among 24 eligible frail elderly, 12 agreed to participate and 3 drop out. The adherence was 15 of 24 intervention sessions. For secondary outcome, effect sizes (ES) for SR-WBV intervention on SPPB, ETGUG and CR were determined. Conclusion This pilot study indicate that the training protocol used in this form for frail elderly individuals is feasible but with modification due to the fact that not all defined feasibility outcomes target was met. SR-WBV with 6 Hz, noise level 4 shows benefit improvements on SPPB (ES 0.52), ETGUG (part sit-to-stand movement: ES 0.81; total time: ES 0.85) and CR (ES 0.66). Further research is desired to determine whether a new adapted training protocol is necessary for SR-WBV in the “skilling up” phase in frail elderly individuals. Keywords Feasibility Adherence Attrition Isometric maximal voluntary contraction Isometric rate of force developmen

NEURAL AND BIOCHEMICAL ASPECTS IN REHABILITATION TRAINING

Physiological training is a well known treatment in rehabilitation and prevention. Endurance training programs are used to optimize cardiovascular functions and thereby reduce the risk of heart diseases or stroke; strength training is efficient to avoid or reduce lower back pain or osteoporosis. However, in the last decade strong experimental evidences suggest that training stimuli are also beneficial in the treatment of neurodegenerative diseases (e.g. PD, MS) and neurotraumata (e.g. SCI). At this neurotrophic factors were identified to play a key role. The release function of these substances is highly related to sensory input, especially muscle spindle afferents. As voluntary muscular activation and motor control is impaired in multiple neurological patients and therefore sensory stimulations are reduced, alternative stimulation techniques are of crucial importance. With respect to natural stochastic behavior of nerve cells, neuromuscular activation can be generated using mechanical stochastic resonance (SR) stimulations. These signals are characterized by a coherent wave which is superimposed by noisy influences. Supra-threshold activations result from resonance like behavior between both stochastic signals

NEURAL AND BIOCHEMICAL ASPECTS IN REHABILITATION TRAINING

Physiological training is a well known treatment in rehabilitation and prevention. Endurance training programs are used to optimize cardiovascular functions and thereby reduce the risk of heart diseases or stroke; strength training is efficient to avoid or reduce lower back pain or osteoporosis. However, in the last decade strong experimental evidences suggest that training stimuli are also beneficial in the treatment of neurodegenerative diseases (e.g. PD, MS) and neurotraumata (e.g. SCI). At this neurotrophic factors were identified to play a key role. The release function of these substances is highly related to sensory input, especially muscle spindle afferents. As voluntary muscular activation and motor control is impaired in multiple neurological patients and therefore sensory stimulations are reduced, alternative stimulation techniques are of crucial importance. With respect to natural stochastic behavior of nerve cells, neuromuscular activation can be generated using mechanical stochastic resonance (SR) stimulations. These signals are characterized by a coherent wave which is superimposed by noisy influences. Supra-threshold activations result from resonance like behavior between both stochastic signals

SIMULATION OF VIBRATIONS IN ALPINE SKIING

Introduction: Simulation of movements has become a significant method in biomechanical research. Especially in alpine ski racing, which is characterized by a great variety of situations, this method is of crucial importance. The main component in alpine skiing technique is the control of vertical load distribution. A few studies have showed that this coordinating capability is considerably influenced by physical conditions. On the one hand, the physical load is related to high external forces, on the other hand, it is the result of oscillating ground reaction forces. The lack of knowledge of how to control vibrations in alpine skiing was the reason for this study. Because of the difficulties in analyzing neurophysiological parameters on the ski slopes, we have developed a simulation system to obtain more information about the control of vibrations in alpine skiing. Methods: To generate vibrations we used a roller ski system with eccentric rolls driven by a treadmill. In view of the results of field studies and theoretical considerations, we worked with a vibration frequency between 4 and 20 Hz and an amplitude between 4 and 21 mm. One group of persons involved in the study were ski teachers from the ‘German Ski Teachers’ Federation’, the other group were recreational skiers. The subjects were subjected to vibrations for about 20 sec. in an upright stance and for the same time in a crouching stance. To measure the generated vibrations and their influence on body movements we used a one dimensional acceleration sensor attached to the middle of the central axis of the ski (sampling frequency 500 Hz), a goniometer (attached to the right knee) and a video system. To assess the vibration control abilities of the subjects we used the parameters ‘resultant acceleration’ and ’amplitude of knee angle’. Results and Discussion: Depending on the used frequency and amplitude the maximum acceleration reached +50/-40 g, the average maximum acceleration in the course of 15 sec. reached +40/-30 g. The data for acceleration measurements on the slope proved to be similar. The statistical data analysis showed significant intra-individual (upright stance/crouching stance) and inter-individual (ski teacher/ recreational skier) differences in resultant acceleration and amplitude of knee angle. The differences depend on the characteristics of the vibration. Conclusion: At this point in our research, we believe that there is an individual optimum of vibration control in regard to frequency and amplitude, depending on anthromethric measurements and physical conditions. These aspects are being researched in a current study

Wie gezielte Unordnung im Training für Ordnung in der Bewegung sorgt : zufällige Schwingungen wirken auf Muskel- und Nervenzellen ein

Seit über zehn Jahren werden am Institut für Sportwissenschaften die Auswirkungen von Vibrationen auf die Bewegungssteuerung des Menschen erforscht. Das Team um Dr. Christian Haas und Prof. Dietmar Schmidtbleicher fand dabei ein weites Funktionsspektrum mit physiologisch positiven, aber auch negativen Effekten. So können gleichförmige hochfrequente Vibrationen zu Wahrnehmungsstörungen führen oder einen Verlust der Reflextätigkeit bewirken. Andererseits verbessert ein Training mit variablen Vibrationsreizen, so genannten »Stochastischen Resonanzen«, die Koordination. Diese ständig wechselnden Reize trainieren das Zusammenspiel zwischen Sensoren, Gehirn und Muskulatur und bewirken effizientere, an die jeweilige Anforderungssituation angepasste Bewegungsabläufe. Interessanterweise zeigen sich diese Effekte sowohl bei Hochleistungsathleten als auch bei Patienten mit Bewegungsstörungen

VIBRATION TRAINING IN REHABILITATION

Voluntary muscular activation is disturbed in both neurological disorders and orthopaedic injuries. Methods that enable bypassing this activation circle are of fundamental importance in order to set functional training stimuli. Besides electrical stimulation and robot supported gait the app'lication of vibration has become an alternative and complemental treatment method in rehabilitation. The most findings of physiological and motor control, effects of vibratory stimuli result from studies in sport science and basic neurophysiological research. Transferring the effects found in healthy subjects to the different areas of application in rehabilitation seems not possible in a linear way. This paper summarizes the different findings and discusses transfer possibilities and problems

Immediate effects after stochastic resonance whole-body vibration on physical performance on frail elderly for skilling-up training: a blind cross-over randomised pilot study

Objective: This pilot study examined the feasibility outcome recruitment, safety and compliance of the investigation for stochastic resonance whole-body vibration (SR-WBV) training. Another aim was to evaluate the effect size of one SR-WBV intervention session on Short Physical Performance Battery (SPPB), Expanded Timed Get Up-and-Go (ETGUG), isometric maximal voluntary contraction (IMVC) and rate of force development (IRFD) and chair rising (CR). Design: Randomised double-blinded controlled cross-over pilot study. Method: Feasibility outcomes included recruitment, safety and compliance. For secondary outcomes, SPPB, ETGUG, IMVC, IRFD and CR were measured before and 2-min after intervention. Nonparametric Rank-Order Tests of Puri and Sen L Statistics to Ranked Data were proposed. Wilcoxon signed-ranked tests were used to analyse the differences after SR-WBV intervention and sham intervention. Treatment effects between the interventions were compared by a Mann-Whitney U test. Results: Among 24 eligible frail elderly, 12 agreed to participate and 3 drop out. The adherence was 15 of 24 intervention sessions. For secondary outcome, effect sizes (ES) for SR-WBV intervention on SPPB, ETGUG and CR were determined. Conclusion: This pilot study indicate that the training protocol used in this form for frail elderly individuals is feasible but with modification due to the fact that not all defined feasibility outcomes target was met. SR-WBV with 6Hz, noise level 4 shows benefit improvements on SPPB (ES 0.52), ETGUG (part sit-to-stand movement: ES 0.81; total time: ES 0.85) and CR (ES 0.66). Further research is desired to determine whether a new adapted training protocol is necessary for SR-WBV in the "skilling up” phase in frail elderly individuals

Using stochastic resonance and strength training as part of a rehabilitation programme for recurrent low back pain treatment: a case study

Low back pain (LBP) is a common disabling health problem that can cause decreased spine proprioception. Stochastic resonance (SR) can influence detection performance, besides improving patients with significant sensory deficits, but have not been thoroughly tested for LBP. This study aimed to examine the application of SR therapy (SRT) and strength training for LBP treatment. The subject was a resistance-trained male in his early thirties. His back pain was unbearable after a strength training session. Standard pain relief alleviated the pain but the LBP developed at a similar intensity after 4 weeks. SRT (4–5 sets ×90 sec, 30-sec rest interval, supine position) was prescribed along with other exercises for 3 weeks (phase 1), and followed by tailor-made strength training for 16 weeks (phase 2). The Oswestry Disability Index was 66.7% (interpreted as “crippled”) prior to first SRT, and reduced to minimal levels of 15.6% and 6.7% after four and seven SRT sessions, respectively. Similarly, pain intensity was ranging from 5 to 9 (distracting-severe) of the Numeric Rating Scale (NRS-11) prior to the first session but this was reduced considerably after four sessions (NRS-11: 0–1). During phase 2, the patient performed without complaining of LBP, two repetitions of bench press exercise at a load intensity of 1.2 his body weight and attained 4 min of plank stabilisation. This LBP management strategy has a clinically meaningful effect on pain intensity, disability, and functional mobility, by receding the recurrent distracting to severe LBP