Animals alter their locomotor mechanics to adapt to a loss of limb function. To better understand their compensatory mechanisms, this study evaluated the changes in the fore-aft ground forces to forelimb lameness and tested the hypothesis that dogs unload the affected limb by producing a nose-up pitching moment via the exertion of a net-propulsive force when the lame limb is on the ground. Seven healthy Beagles walked and trotted at steady speed on an instrumented treadmill while horizontal force data were collected before and after a moderate lameness was induced. Peak, mean and summed braking and propulsive forces as well as the duration each force was exerted and the time to reach maximum force were evaluated for both the sound and the lame condition. Compared with the sound condition, a net-propulsive force was produced by the lame diagonal limbs due to a reduced braking force in the affected forelimb and an increased propulsive force in the contralateral hindlimb when the dogs walked and trotted. To regain pitch stability and ensure steady speed for a given locomotor cycle, the dogs produced a net-braking force when the sound diagonal limbs were on the ground by exerting greater braking forces in both limbs during walking and additionally reducing the propulsive force in the hindlimb during trotting. Consistent with the proposed mechanism, dogs maximize their double support phases when walking. Likely associated with the fore-aft force adaptations to lameness are changes in muscle recruitment that potentially result in short- and long-term effects on the limb and trunk muscles. arabic 13 English 78
Jalal Mohamed Abdelhadi(12-2012)

Objective: To evaluate the load redistribution mechanisms in walking and trotting dogs with induced forelimb lameness. Animals: 7 healthy adult Beagles. Procedures: Dogs walked and trotted on an instrumented treadmill to determine control values for peak and mean vertical force as well as vertical impulse for all 4 limbs. A small sphere was attached to the ventral pad of the right forelimb paw to induce a reversible lameness, and recordings were repeated for both gaits. Additionally, footfall patterns were assessed to test for changes in temporal gait variables. Results: During walking and trotting, peak and mean vertical force as well as vertical impulse were decreased in the ipsilateral forelimb, increased in the contralateral hind limb, and remained unchanged in the ipsilateral hind limb after lameness was induced. All 3 variables were increased in the contralateral forelimb during trotting, whereas only mean vertical force and vertical impulse were increased during walking. Stance phase duration increased in the contralateral forelimb and hind limb during walking but not during trotting. Conclusions and clinical relevance: Analysis of the results suggested that compensatory load redistribution mechanisms in dogs depend on the gait. All 4 limbs should be evaluated in basic research and clinical studies to determine the effects of lameness on the entire body. Further studies are necessary to elucidate specific mechanisms for unloading of the affected limb and to determine the long-term effects of load changes in animals with chronic lameness arabic 10 English 72
Jalal Mohamed Abdelhadi(1-2013)

Poor performance in athletic horses due to musculoskeletal affections is very common in Libya. Two mature thoroughbred horses suffering from poor performance and history of moderate degree forelimb lameness were admitted to the Aswany Private Equine clinic in Tripoli, Libya. The study is aiming for presenting a simple, time effective, cost effective surgical procedure to treat distal simple splint bone fracture in thoroughbred horses. Horses were examined thoroughly for the common muscle, hoof, and tendons affections. A progressed unilateral left forelimb swelling involving the lateral distal part of the fourth metacarpal bones was noticed. Three radiographs were taken to each horse including latero- medial, dorsolateral-palmaromedial, and palmarolateral-dorsomedial views to assess both splint bones. The radiographs showed that there is a complete fracture involving the distal extremity (button) of the fourth metacarpal bones. Surgical excisions of the fractured part of the splint bones have been decided to treat these horses. To precisely locate the site of the bone fragments, 1.5 mm stainless steel wires were placed over the distal part of splint prior to taking the radiographs. The surgical sites were aseptically prepared, and the horses were then sedated via intravenous injection of xylazine at a dose rate of 1 mg/kg body weight. The site of surgical incision was infiltrated with 2% lidocaine. The bone fragments were then removed after performing the surgical incision. The sharp end at the distal end of the proximal part of the splint bone was then smoothening with a scissor. The surgical incisions were then routinely closed and the post-operative care and radiographs were taken. The surgical incision made complete healing within two weeks. Both horses were followed up for up to three years post-operation, and they did well compared to what has been done in other studies. We concluded that the surgical technique used to treat the two horses with splint bone fracture enrolled in the current study is a simple and effective procedure. arabic 19 English 106
Mohamed H. Abushhiwa, Osma K Sawesi, Khaled A. Milad, Aiman. A. Shalgum, Abdulrhman Mohamed Salah Alrtib(9-2019)