Abstract: A chiropractic adjusting instrument comprising a housing; thrust nose piece an impact head to contact a body, a preload switch plunger; a dampening spring; a solenoid having a core; a preload spring; a recoil spring; an electronic pulse system operatively connected to a power source to provide alternating current for energizing the solenoid to impart impulse energy from the core to the thrust nose piece which is reproducible and independent of the power source; and a trigger system for triggering the electronic pulse system comprising a switch activated by the preload switch plunger. Preferably, the chiropractic adjusting instrument includes one or more of the following: an intelligent universal AC power converter; optimized force-time waveform; pulse mode operation; a sensing device having a sense output and a suite of electromechanical components designed to promote reproducible dynamic force impulses and safe operation.

Abstract: A chiropractic adjusting instrument comprising a housing; a thrust nose piece and an impact head to contact a body; a preload switch plunger; a dampening spring; a solenoid having a core; a preload spring; a recoil spring; an electronic pulse system operatively connected to a power source to provide alternating current for energizing the solenoid to impart impulse energy from the core to the thrust nose piece which is reproducible and independent of the power source; and a trigger system for triggering the electronic pulse system comprising an switch activated by the preload switch plunger. Preferably, the chiropractic adjusting instrument includes one or more of the following: an intelligent universal AC power converter; optimized force-time waveform; pulse mode operation; a sensing device having an sense output and a suite of electromechanical components designed to promote reproducible dynamic force impulses and safe operation.

Abstract: A chiropractic adjusting instrument comprising a housing; a thrust nose piece and an impact head to contact a body; a preload switch plunger; a dampening spring; a solenoid having a core; a preload spring; a recoil spring; an electronic pulse system operatively connected to a power source to provide alternating current for energizing the solenoid to impart impulse energy from the core to the thrust nose piece which is reproducible and independent of the power source; and a trigger system for triggering the electronic pulse system comprising an switch activated by the preload switch plunger. Preferably, the chiropractic adjusting instrument includes one or more of the following: an intelligent universal AC power converter; optimized force-time waveform; pulse mode operation; and a suite of electromechanical components designed to promote reproducible dynamic force impulses and safe operation.

Abstract: Studies investigating posteroanterior (PA) forces in spinal stiffness assessment have shown relationships to spinal level, body type, and lumbar extensor muscle activity. Little objective evidence is available discerning variation in PA stiffness and its clinical significance. The aim of this prospective clinical study was to determine the stiffness index and neuromuscular characteristics of the asymptomatic and symptomatic low back. Twenty-two subject underwent physical examination and completed outcome VAS, Oswestry, and SF-36 questionnaires. A hand-held spinal manipulation instrument, equipped with a load cell and accelerometer was used to deliver high rate (<0.1 sec) PA manipulative thrusts (450 N) to several common spinal landmarks including the posterior superior iliac spine (PSIS), sacral base, and L5, L4, L2, T12, T8 spinous (SP) and transverse processes (TP).

Abstract: Studies investigating posteroanterior (PA) forces in spinal stiffness assessment have shown relationships to spinal level, body type, and lumbar extensor muscle activity. Little objective evidence is available discerning variation in PA stiffness and its clinical significance. The aim of this prospective clinical study was to determine the stiffness index and neuromuscular characteristics of the asymptomatic and symptomatic low back. Twenty-two subject underwent physical examination and completed outcome VAS, Oswestry, and SF-36 questionnaires. A hand-held spinal manipulation instrument, equipped with a load cell and accelerometer was used to deliver high rate (<0.1 sec) PA manipulative thrusts (450 N) to several common spinal landmarks including the posterior superior iliac spine (PSIS), sacral base, and L5, L4, L2, T12, T8 spinous (SP) and transverse processes (TP).

Abstract: A non-invasive method for determining the dynamic biomechanical characteristics (frequency response functions and natural frequency) of a musculoskeletal structure is provided. The method generally comprises exciting the musculoskeletal structure over a broad range of frequencies with a low amplitude, high velocity impulsive input force, measuring the input force with a force transducer, detecting the output motion response with an output transducer, processing input force and output response data into time-signal histories with a data acquisition and analysis means or digital computer, transforming the time-signal histories from the time domain to the frequency domain by applying Fourier analysis; and calculating a frequency response function and the natural frequency from the input force and dynamic output response time-signal histories.

Abstract: A non-invasive method and apparatus for determining the dynamic biomechanical characteristics (frequency response functions and natural frequency) of a musculoskeletal structure is provided. The method generally comprises exciting the musculoskeletal structure over a broad range of frequencies with a low amplitude, high velocity impulsive input force, measuring the input force with a force transducer, detecting the output motion response with an output transducer, processing input force and output response data into time-signal histories with a data acquisition and analysis means or digital computer, transforming the time-signal histories from the time domain to the frequency domain by applying Fourier analysis; and calculating a frequency response function and the natural frequency from the input force and dynamic output response time-signal histories.

Abstract: An improved chiropractic adjusting instrument and method is provided for use in spinal manipulative therapy and for exciting a human spine at its natural frequency. The chiropractic adjusting instrument includes a thrust element for delivering an input force, a body contact member removably attached to the thrust element, a spring member for propelling the thrust element and the body contact member outwardly, and an adjustment knob arranged on the thrust element for adjusting the amount of potential energy imposed on the spring member and for controlling the magnitude of the resulting input force. In use, the input force is mechanically tuned to the natural frequency of a musculoskeletal structure (e.g., a human spine) by positioning a shaped mass on the thrust element, by varying the stiffness of the removable body contact member, and/or by varying the stiffness of the spring member. The input force is then delivered to the musculoskeletal structure at its natural frequency.

Abstract: An improved chiropractic adjusting instrument is provided for use in spinal manipulative therapy and for exciting a human spine at its natural frequency. The chiropractic adjusting instrument includes a thrust element for delivering an input force, a body contact member removably attached to the thrust element, a spring means for propelling the thrust element and the body contact member outwardly, and an adjustment knob arranged on the thrust element for adjusting the amount of potential energy imposed on the spring means and for controlling the magnitude of the resulting input force. In use, the input force is mechanically tuned to a desired frequency (e.g., the natural frequency of a human spine) by positioning a shaped mass on the thrust element. By mechanically tuning the chiropractic adjusting instrument in this way, the dynamic output response of the spine is maximized while the requisite impact force is minimized.

Abstract: A dynamic prosthetic vertebral body for use in a cavity left by resection of a natural vertebral body and adjacent intervertebral discs. The prosthesis includes a pair of rigid housings joined by a connecting structure that is operable to shift the housings apart into supportive engagement with the healthy vertebral bodies adjacent the site of the resected body. Anchoring pins project outwardly in axial directions from the respective housings for secure fixation to the healthy vertebral bodies. Within the chamber of each housing is a rigid suspension plate surrounded by an elastomeric suspension medium, and the suspension plates of the two housings are joined by the expandable connecting structure. The relative sizes of the suspension plates and the chambers in which they are received allow limited movement of the housings, resulting in a prosthesis that provides the required support but also mimics the dynamics of a normal vertebra and adjacent discs.