Bokt.nl

Quir schreef:

Een rijbak moet een bodem hebben waar de voet van het paard niet verder dan 3cm in weg zakt (niet meer en niet minder). Dat is de beste bodem om op te rijden. Ook instappen en uitstappen op harde bodem is het beste (asfalt of iets dergelijks).

Ik stapte in Nederland ook vrijwel altijd op het harde uit, nu heb ik daar niet echt de mogelijkheid voor. Aangezien er vrijwel geen asfalt of harde wegen zijn.

Citaat:

Functional adaptation of articular cartilage from birth to maturity under the influence of loading: a biomechanical analysis
Reasons for performing study: The concept of functional adapatation of articular cartilage during maturation has emerged from earlier biochemical research. However, articular cartilage has principally a biomechanical function governed by joint loading.

Objectives: To verify whether the concept of functional adaptation can be confirmed by direct measurement of biomechanical properties of cartilage.

Hypothesis: Fetuses have homogeneous (i.e. site-independent) cartilage with regard to biomechanical properties. During growth and development to maturity, the biomechanical characteristics adapt according to functional (loading) demands, leading to distinct, site-dependent biomechanical heterogeneity of articular cartilage.

Methods: Osteochondral plugs were drilled out of the surface at 2 differently loaded sites (Site 1: intermittent impact-loading during locomotion, Site 2: low-level constant loading during weightbearing) of the proximal articular cartilage surface of the proximal phalanx in the forelimb from stillborn foals (n = 8), horses of age 5 (n = 9) and 18 months (n = 9) and mature horses (n = 13). Cartilage thickness was measured using ultrasonic, optical and needle-probe techniques. The osteochondral samples were biomechanically tested in indentation geometry. Young's modulus at equilibrium, dynamic modulus at 1 Hz and the ratios of these moduli values between Sites 1 and 2 were calculated. Age and site effects were evaluated statistically using ANOVA tests. The level of significance was set at P < 0.05.

Results: Fetal cartilage was significantly thicker compared to the other ages with no further age-dependent differences in cartilage thickness from age 5 months onwards. Young's modulus stayed constant at Site 1, whereas at Site 2 there was a gradual, statistically. significant increase in modulus during maturation. Values of dynamic modulus at both Sites 1 and 2 were significantly higher in the fetus and decreased after birth. Values for both moduli were significantly different between Sites 1 and 2 from age 18 months onwards. The ratio of values between Sites 1 and 2 for Young's modulus and dynamic modulus showed a gradual decrease from similar to1.0 at birth to 0.5-0.6 in the mature horse. At age 18 months, all values were comparable to those in the mature horse.

Conclusions: In line with the concept of functional adaptation, the neonate is born with biomechanically 'blank' or homogeneous cartilage. Functional adaptation of biomechanical properties takes place early in life, resulting in cartilage with a distinct heterogeneity in functional characteristics. At age 18 months, functional adaptation, as assessed by the biomechanical characteristics, has progressed to a level comparable to the mature horse and, after this age, no major adaptations seem to occur.

Potential relevance: Throughout life, different areas of articular cartilage are subjected to different types of loading. Differences in loading can adequately be met only when the tissue is biomechanically adapted to withstand these different loading conditions without injury. This process of functional adaptation starts immediately after birth and is completed well before maturity. This makes the factor of loading at a young age a crucial variable, and emphasises the necessity to optimise joint loading during early life in order to create an optimal biomechanical quality of articular cartilage, which may well turn out to be the best prevention for joint injury later in life.

Citaat:

Brommer adds, "The main risk of giving a young horse additional exercise is that the exercise may be too much, leading to overloading of the cartilage, which may result in damage on a young age, including joint disease and impaired performance. It is obvious that a thorough investigation in the search for a well balanced exercise program is of utmost importance to achieve the most optimal conditioning of the articular cartilage."