TY  - JOUR
A1  - Heinke, Lars N.
A1  - Knicker, Axel J.
A1  - Albracht, Kirsten
T1  - Evaluation of passively induced shoulder stretch reflex using an isokinetic dynamometer in male overhead athletes
JF  - Isokinetics and Exercise Science
N2  - BACKGROUND: Muscle stretch reflexes are widely considered to beneficially influence joint stability and power generation in the lower limbs. While in the upper limbs and especially in the muscles surrounding the shoulder joint such evidence is lacking. OBJECTIVE: To quantify the electromyographical response in the muscles crossing the shoulder of specifically trained overhead athletes to an anterior perturbation force. METHODS: Twenty healthy male participants performed six sets of different external shoulder rotation stretches on an isokinetic dynamometer over a range of amplitudes and muscle pre-activation moment levels. All stretches were applied with a dynamometer acceleration of 10,000∘/s2 and a velocity of 150∘/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexes were not observed in all experimental conditions. The reflex latencies revealed a significant muscle main effect (F (2,228) = 99.31, p< 0.001; η2= 0.466; f= 0.934) and a pre-activation main effect (F (1,228) = 142.21, p< 0.001; η2= 0.384; f= 1.418). The stretch reflex amplitude yielded a significant pre-activation main effect (F (1,222) = 470.373, p< 0.001; η2= 0.679; f= 1.454). CONCLUSION: Short latency muscle reflexes showed a tendency to an anterior to posterior muscle recruitment whereby the main internal rotator muscles of the shoulder revealed the most consistent results.
Y1  - 2018
U6  - http://dx.doi.org/10.3233/IES-184111
SN  - 1878-5913
VL  - 26
IS  - 4
SP  - 265
EP  - 274
PB  - IOS Press
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Chloé, Radermacher
A1  - Malyaran, Hanna
A1  - Craveiro, Rogerio Bastos
A1  - Peglow, Sarah
A1  - Behbahani, Mehdi
A1  - Pufe, Thomas
A1  - Wolf, Michael
A1  - Neuss, Sabine
T1  - Mechanical loading on cementoblasts: a mini review
JF  - Osteologie
N2  - Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments.
KW  - Cementoblast
KW  - Compression
KW  - Tension
KW  - Mechanotransduction
KW  - Forces
Y1  - 2022
U6  - http://dx.doi.org/10.1055/a-1826-0777
SN  - 1019-1291
VL  - 31
IS  - 2
SP  - 111
EP  - 118
PB  - Thieme
CY  - Stuttgart
ER  -