The purpose of this thesis is to describe the gait kinematics and kinetics of children with a lower limb deficiency. This thesis has furthered the knowledge and understanding of the adaptations made during gait, providing analysis techniques that can assist the rehabilitation clinic in making principled decisions regarding the care of this population. Participants in this study were examined while wearing their prescribed prosthesis, without any prosthetic intervention prior to testing. This unique approach has enhanced both our theoretical and practical understanding of the mechanical perturbation and its influence on inter-joint coordination and lower limb mechanics.
This thesis utilises three-dimensional gait analysis to investigate these adaptations. Fifteen lower limb deficient children participated and a multiple case study design was employed to detect individual differences associated with aetiology and prosthetic
componentry. Data from participants with similar levels of deficiency were also combined to develop a broader understanding of the potential contributors to the functional adaptations identified during locomotion.
A physiotherapy and prosthetic evaluation were completed prior to the participant being instructed to walk at a self-selected pace along an 8m walkway. Kinematic data were collected with a six camera ExpertVision system (Motion Analysis Corporation, CA) at a sampling rate of 60Hz. Three AMTI force plates (Newton, Massachusetts) collected data simultaneously at 1000Hz for the calculation of joint kinetics. All data were processed using specialised software to obtain joint rotations and joint kinetics. The topological dynamics of locomotion were used to describe patterns of control. These data were compared to data from age and height matched able-bodied children to identify and describe the mechanical and neuromuscular adaptations.
Adaptations are a function of the asymmetrical extrinsic compensation, which is variable in children due to factors such as growth, amputation level, and high physical demands that can break components or alter fit and alignment of the prosthesis. This thesis established that children with a partial foot amputation were unable to utilise the additional degree of freedom to generate power when compared to participants with an ankle disarticulation. This was in part compensated by a change in coordination between the ankle and hip joints. The dominant cause of adaptation in children with a below-knee amputation was related to the length of the prosthetic heel level. This was principally accommodated by a change in mechanics at the knee joint. These adaptations may be readily identified using a proposed classification system. This thesis also demonstrated that the prosthetic knee joint has an instrumental role in determining the control strategy adapted by participants with an
above-knee amputation, and that an individual's gait dynamics can be altered through changes in prosthetic componentry and alignment.
This thesis provides evidence that specific adaptations may be identified through three-dimensional analysis. A classification system, and symmetry indices developed in this thesis, assist in identifying the causes of adaptation during gait in children with a lower limb amputation to ultimately improve rehabilitation outcome through either physical therapy or prosthetic intervention.