Leg problems and disorders are of major concern for the poultry industry and animal welfare. Previous studies suggest that it may be possible to improve skeletal characteristics through nutrition. Omega-3 fatty acids, including Docosahexaenoic acid (DHA), are essential nutrients and are known to play an important role in bone tissue development. FORPLUS™ (Alltech, Inc.) is an unextracted, whole-cell microalgae (Aurantiochytrium limacinum CCAP 4087/2) that contains 64% fat and 16% DHA. Zinc (Zn) is a trace element and essential nutrient for growth and skeletal development. Bioplex® Zn (Alltech, Inc.) is a Zn proteinate that has been shown to be more bioavailable to broiler chickens compared to inorganic sources of Zn. One objective of this research was to investigate the effects of 2 dietary levels of FORPLUS™ (0% vs. 2%) and 2 dietary Zn sources (ZnO vs. Bioplex® Zn) on skeletal characteristics and reproduction of broiler breeders. Breeders were maintained on these diets throughout the entire pullet and layer phases. Subsequent studies were conducted to evaluate the effect of breeder diet and offspring dietary Zn sources (ZnO vs. Bioplex® Zn) and microalgae supplementation (0% vs. 1%) on offspring performance and skeletal characteristics. During the broiler breeder pullet phase, dietary supplementation of 2% FORPLUS™ increased (P < 0.05) femur ash content and length. Pullet uniformity was in increased (P < 0.05) by Bioplex® Zn vs ZnO when microalgae was not included in the diet. Hen day production (HDP) was increased (P < 0.05) by ZnO vs. Bioplex® Zn supplementation during post-peak lay. During post-peak lay, hatchability and hatch of fertile eggs were improved (P < 0.05) by dietary supplementation of 2% FORPLUS™ or Bioplex® Zn in breeder diets, however egg weight, egg yolk weight, offspring hatch weight, and offspring body weight gain (BWG) significantly were decreased (P < 0.05) by 2% FORPLUS™. Bioplex® Zn in breeder diets increased (P < 0.05) growth plate zone heights, bone-specific alkaline phosphatase enzyme activity, and dimensions of offspring bones at hatch. At 3 weeks of age, offspring from breeders fed Bioplex® Zn during peak-lay had greater (P < 0.05) Zn content in tibia ash and bone dimensions, while offspring from breeders fed 2% FORPLUS™ vs. 0% FORPLUS™ had longer (P < 0.05) femurs. No interaction effect of breeder diet and offspring diet on early performance was observed. Offspring fed diets containing Bioplex® Zn vs. ZnO had greater (P < 0.05) body weight (BW) and tibia dimensions at 3 wk of age. Offspring fed diets containing 1% FORPLUS™ had decreased feed conversion (feed intake: BWG), but no main effects were observed on skeletal characteristics. Overall, dietary microalgae supplementation in broiler breeder diets improved early bone development in broiler breeders, early bone development in broiler breeder offspring, and hatchability of offspring during post-peak lay, while Bioplex® Zn supplementation in broiler breeder diets improved broiler breeder pullet uniformity, offspring hatchability during post-peak lay, embryonic skeletal development of offspring, and offspring bone quality. Bioplex® Zn in offspring diets also improved offspring early growth performance and leg bone morphology.

In children, joint hypermobility (typified by structural instability of joints) manifests clinically as neuro-muscular and musculo-skeletal conditions and conditions associated with development and organization of control of posture and gait (Finkelstein, 1916; Jahss, 1919; Sobel, 1926; Larsson, Mudholkar, Baum and Srivastava, 1995; Murray and Woo, 2001; Hakim and Grahame, 2003; Adib, Davies, Grahame, Woo and Murray, 2005:). The process of control of the relative proportions of joint mobility and stability, whilst maintaining equilibrium in standing posture and gait, is dependent upon the complex interrelationship between skeletal, muscular and neurological function (Massion, 1998; Gurfinkel, Ivanenko, Levik and Babakova, 1995; Shumway-Cook and Woollacott, 1995). The efficiency of this relies upon the integrity of neuro-muscular and musculo-skeletal components (ligaments, muscles, nerves), and the Central Nervous System’s capacity to interpret, process and integrate sensory information from visual, vestibular and proprioceptive sources (Crotts, Thompson, Nahom, Ryan and Newton, 1996; Riemann, Guskiewicz and Shields, 1999; Schmitz and Arnold, 1998) and development and incorporation of this into a representational scheme (postural reference frame) of body orientation with respect to internal and external environments (Gurfinkel et al., 1995; Roll and Roll, 1988). Sensory information from the base of support (feet) makes significant contribution to the development of reference frameworks (Kavounoudias, Roll and Roll, 1998). Problems with the structure and/ or function of any one, or combination of these components or systems, may result in partial loss of equilibrium and, therefore ineffectiveness or significant reduction in the capacity to interact with the environment, which may result in disability and/ or injury (Crotts et al., 1996; Rozzi, Lephart, Sterner and Kuligowski, 1999b). Whilst literature focusing upon clinical associations between joint hypermobility and conditions requiring therapeutic intervention has been abundant (Crego and Ford, 1952; Powell and Cantab, 1983; Dockery, in Jay, 1999; Grahame, 1971; Childs, 1986; Barton, Bird, Lindsay, Newton and Wright, 1995a; Rozzi, et al., 1999b; Kerr, Macmillan, Uttley and Luqmani, 2000; Grahame, 2001), there has been a deficit in controlled studies in which the neuro-muscular and musculo-skeletal characteristics of children with joint hypermobility have been quantified and considered within the context of organization of postural control in standing balance and gait. This was the aim of this project, undertaken as three studies. The major study (Study One) compared the fundamental neuro-muscular and musculo-skeletal characteristics of 15 children with joint hypermobility, and 15 age (8 and 9 years), gender, height and weight matched non-hypermobile controls. Significant differences were identified between previously undiagnosed hypermobile (n=15) and non-hypermobile children (n=15) in passive joint ranges of motion of the lower limbs and lumbar spine, muscle tone of the lower leg and foot, barefoot CoP displacement and in parameters of barefoot gait. Clinically relevant differences were also noted in barefoot single leg balance time. There were no differences between groups in isometric muscle strength in ankle dorsiflexion, knee flexion or extension. The second comparative study investigated foot morphology in non-weight bearing and weight bearing load conditions of the same children with and without joint hypermobility using three dimensional images (plaster casts) of their feet. The preliminary phase of this study evaluated the casting technique against direct measures of foot length, forefoot width, RCSP and forefoot to rearfoot angle. Results indicated accurate representation of elementary foot morphology within the plaster images. The comparative study examined the between and within group differences in measures of foot length and width, and in measures above the support surface (heel inclination angle, forefoot to rearfoot angle, normalized arch height, height of the widest point of the heel) in the two load conditions. Results of measures from plaster images identified that hypermobile children have different barefoot weight bearing foot morphology above the support surface than non-hypermobile children, despite no differences in measures of foot length or width. Based upon the differences in components of control of posture and gait in the hypermobile group, identified in Study One and Study Two, the final study (Study Three), using the same subjects, tested the immediate effect of specifically designed custom-made foot orthoses upon balance and gait of hypermobile children. The design of the orthoses was evaluated against the direct measures and the measures from plaster images of the feet. This ascertained the differences in morphology of the modified casts used to mould the orthoses and the original image of the foot. The orthoses were fitted into standardized running shoes. The effect of the shoe alone was tested upon the non-hypermobile children as the non-therapeutic equivalent condition. Immediate improvement in balance was noted in single leg stance and CoP displacement in the hypermobile group together with significant immediate improvement in the percentage of gait phases and in the percentage of the gait cycle at which maximum plantar flexion of the ankle occurred in gait. The neuro-muscular and musculo-skeletal characteristics of children with joint hypermobility are different from those of non-hypermobile children. The Beighton, Solomon and Soskolne (1973) screening criteria successfully classified joint hypermobility in children. As a result of this study joint hypermobility has been identified as a variable which must be controlled in studies of foot morphology and function in children. The outcomes of this study provide a basis upon which to further explore the association between joint hypermobility and neuro-muscular and musculo-skeletal conditions, and, have relevance for the physical education of children with joint hypermobility, for footwear and orthotic design processes, and, in particular, for clinical identification and treatment of children with joint hypermobility.