AlterG Bionic Leg Dan Lewis, PT Deb Soares OTR/L ----- Meeting Notes (4/10/14 07:29) -----

Anti-Gravity Treadmill AlterG Products Anti-Gravity Treadmill Bionic Leg AlterG AlterG now offers two unique high-tech mobility solutions for the rehab market. Both products facilitate greater amounts of rehab activities and the ability to progress patients to higher level activities than would otherwise be possible. ----- Meeting Notes (4/10/14 07:29) ----- DAN

Potential Influence of AlterG Technology AlterG Bionic Leg & AlterG Anti-Gravity Treadmill Motor and Sensory Input Increased ROM, strength Varied repetition at limit of performance. Feedback from successful performance Neuroplasticity/ Motor Learning Improved Performance Reduce Support (BW %, Threshold, Assistance) Burridge, Feb 2009. Participation in greater massed practice, with feedback leads to strength gains. Varying the practice conditions to keep the patient challenged near their current limit of performance leads to greater potential for motor learning. Customizable settings allow the therapy to be progressed for continual challenge to the patient. ----- Meeting Notes (4/10/14 07:29) ----- DAN

AlterG Bionic Leg The Bionic Leg translates patient intention into robotic assistance. It does this through weight sensors under the patient’s foot, along with motion sensors at the knee. The assistance is entirely customizable by the treating clinician. ----- Meeting Notes (4/10/14 07:29) ----- DAN

The Bionic Leg - What is it? Robotic leg orthosis Robotic assistance based on patient initiated movement Two dynamic motors High torque for up and down High speed to enable swing phase Foot sensors are miniature load cells that sense downward pressure to activate the leg Programmable for appropriate level of assistance as patient progresses Again, the key is active patient participation in initiating movement that is required to trigger the assistance from the device. The high-speed motor allows the device to move “out of the way” when assistance is NOT required. This allows for the maximum participation by the patient. This ability to “get out of the way” is referred to as “transparency” in robotic devices and is believed to help drive functional improvements by allowing for greater patient participation. ----- Meeting Notes (4/10/14 07:29) ----- DAN

Dynamic, “As Needed” Assistance Weight shift triggers: Assistance (stand) Resistance (sit) Stabilization (walk) Weight shift and knee motion trigger assistance with knee extension and resistance to knee flexion. This, along with the physical support of the device act to stabilize the patient’s weak leg in all standing activities. The amount of assistance and resistance provided are highly customizable, based on the patient’s needs. ----- Meeting Notes (4/10/14 07:29) ----- DAN Easily Programmable to Match Patient’s Functional Level

Leg Specs Leg weight approx. 8 lbs. Minimum to maximum patient height 5’-6’6” Minimum to maximum weight appx 100-300 lbs. Battery life-1-2 hours, requires only 45 min to charge Foot sensors 4 sizes each side, total of 8 included ----- Meeting Notes (4/10/14 07:29) ----- DAN

Clinical Benefits: Confidence for Patients and Therapists Allows patients to safely do more repetitions of higher level activities Strengthens muscles and enables active motor learning Allows therapist to focus on function-not lifting patient Improves functional mobility with carry over Pre Gait Activities - Improve stance stability, weight shift, balance Safely supports patient, protects therapist ----- Meeting Notes (4/10/14 07:29) ----- DEB

Clinical Benefits Another “tool in the toolbox” for therapists Allows low mobility patients to perform standing/functional activities Something to integrate into existing therapy to be more effective Provides stance stability Gives patient and therapist a stable base to work from Like an “extra set of hands for the therapist” Allows the therapist to better facilitate quality of motion Patients will usually have instability further up the chain from the knee. I initially hear this from therapists, but by stabilizing at the knee, we now have a stable base for the patient to work from, performing standing functional activities that can strengthen at the hip, pelvis and trunk. ----- Meeting Notes (4/10/14 07:29) ----- DEB

Maximizes Inputs Needed for Effective Therapy Effective, Durable Therapy Improves Confidence Maximizes Repetitions Increases Intensity, Engagement Corrects Biomechanical Movement

First patients: (57 Year old, 8 Years s/p stroke) Before - “Compensatory for Life” After - “Independent Safety” Today, 2 years post study: .45 m/s Ambulation (m/s) Endurance (m) Berg Balance .05 23 Initial assessment Show 1st and last 5 sec .13 38 40 After 4 weeks, 2 sessions/week .17 66 50 1 month after end of treatment

DIAGNOSES Difficulty with sit to stand Poor gait symmetry IMPAIRMENTS Lower extremity weakness Decreased stance stability Decreased standing tolerance Ataxia Asymmetrical weight-bearing Decreased active knee extension Decreased terminal knee extension control Decreased proprioreception/sensation Inattention/neglect *Balance dysfunction FUNCTIONAL DEFICITS Difficulty with sit to stand Poor gait symmetry Flexed posture Stairs DIAGNOSES CVA TBI Incomplete Spinal Cord Injury Parkinson’s MS Post-hip or knee replacement When I train clinicians, I try to focus on impairments and functional deficits rather than diagnoses. This is to create the broadest “filter” for inclusion initially and narrow down from there who the device is appropriate for. ----- Meeting Notes (4/10/14 07:29) ----- DEB

Precautions and Contraindications What are the contraindications? Unresolved/resolving DVT Open wounds Active drug-resistant infection Recent/unstable fracture, ie. any weight-bearing restrictions And the precautions? Osteoporosis/long-term use of osteoporosis medications Consider this with all SCI patients Unstable cardiovascular conditions/unstable for exercise PAD (insufficiency) peripheral arterial disease Incontinence (multiple patient use) ----- Meeting Notes (4/10/14 07:29) ----- DEB

Programmable Settings Threshold % of body weight needed to activate Assistance Amount of assistance provided during knee extension Resistance Amount of resistance provided during knee flexion ----- Meeting Notes (4/10/14 07:29) ----- DEB

Sit to Stand Stair Climbing Gait Weight Shifting The device is used to assist patients in performing more of any standing activity, from early attempts to get patients up from sitting, to facilitating better and more symmetrical LE weight bearing, to improving gait symmetry and endurance. It’s also very useful in progressing patients to stair climbing and getting back to reciprocal stair climbing. ----- Meeting Notes (4/10/14 07:29) ----- DEB

Supporting Principles of Motor Learning Why Use the Bionic Leg?

Theories Have Evolved Research in motor control/motor learning has more recently begun to make an impact on the practice of rehabilitation. Rehabilitation typically focused on passive facilitation of isolated movements or teaching patients to compensate for lost movement Traditional view was that the motor cortex was static, with specific areas of the cortex dedicated to specific areas of the body. We now know this is not the case and that the firing patterns within the cortex are plastic and changeable and that they change based on the activities that are performed.

Neural circuits not actively engaged for an extended time degrade. Use It or Lose It Neural circuits not actively engaged for an extended time degrade. Use It & Improve It Plasticity can be induced in specific areas of the brain with extended training Specificity Neural changes are dependent on specific types of experience Repetition Permanent change is dependent on sufficient repetition Intensity Low intensity repetition = weakened response Higher intensity = long-term changes Time Learning is most effective when training begins soon after injury Salience Tasks that have meaning to the learner promote better learning

In a review of rehabilitation approaches after neurological injury, the greatest improvements were seen with high intensity, repetitive, task-specific interventions, regardless of impairment or technique being used Task Specific High Intensity Repetition Motor Learning TASK SPECIFC! The tasks practiced must be as close to the real world task as possible. Practicing isolated movements only leads to improved ability to perform those isolated movements. Therefore, rehab activities must be structured to maximize practice of varied and functional tasks. The BL allows for exactly this process – greater repetitions of higher-level functional activities.

Use It or Lose It Bionic Leg – Facilitates use of involved limb during mobility tasks. Drives increased engagement and attention of involved side. Volitional movement required to activate device Increased (customized) threshold = increased initiated movement of involved limb required to activate device. By facilitating active use of the involved limb, we are achieving task specific practice and can then customize the settings to appropriately and progressively challenge the patient. The therapy can be progressed to remain challenging for the patient as mobility improves.

Repetition The lesson is that there are multiple limiting factors in completing high levels of repetition. Patient weakness and fatigue, therapist fatigue and both patient and therapist safety. We know it requires very high repetitions to learn new tasks, so the BL allows us to safely complete more repetitions than could otherwise be completed.

High Repetitions Intensive practice means tons of reps…hundreds a day Canning C, et al., A randomized controlled trial of the effects of intensive sit-to-stand training after recent traumatic brain injury on sit-to-stand performance, Clinical Rehabilitation, 2003; 17:355-362. 24 subjects randomized (11 control/13 experimental) Trained over four weeks Targeted 100 reps of sit to stand and 60 step ups per day; five days a week Varied chair and step height over the four weeks 62% improvement in motor performance (sit to stand) for experimental compared to 18% for control. In addition to their usual rehabilitation Program subjects in the experimental group participated in 4weeks of intensive training of sit-to-stand and step-up exercises The control group did no additional sit-to-stand or step-up training.

Sensory Input/Feedback Feedback can enhance motor learning Self correction occurs when user applies feedback to performance enhancement Focuses users attention Feedback comes in many forms – including visual – consider videotaping your clients before and after device use Van Vliet P, et al., Extrinsic feedback for motor learning after stroke: What is the evidence?, Disability and Rehab, 2006; 28(13-14): 831-840. Engardt M, et al., Vertical ground reaction force feedback to enhance stroke patients' symmetrical body- weight distribution while rising/ sitting down., Scand J Rehab Med 1993; 25:41-48. Feedback is a key component to motor learning. Patients learn best when they are able to self correct in response to feedback. The device provides sensorimotor feedback, audible feedback and proprioceptive feedback during exercise. These afferent inputs are frequently missing in many neurologic conditions so use of the device give greater CNS input than is received without the BL.

Clinical Studies

Clinical Evidence: Summary of Findings UCSF Increased endurance, gait speed, stride length With carryover – improvements maintained post therapy Columbia University Improvements in endurance, gait speed, balance Again, maintained after the treatment - Carryover plus continued improvement Tested 1 month and 3 months post treatment University of Florida (Publication pending) Improved Antero-Postero Stability, i.e. decreased fall risk EMG phasing improved toward “normal” or less compensatory Two published and one pending study completed. Multiple single-patient case studies underway in a constant effort to create treatment examples and protocols. UCSF and Columbia looked at chronic CVA patients – notorious for plateauing in therapy and regressing over time. Difficult to change ingrained patterns but patients were able to make gains.

Outcomes from UCSF Study 10 meter walk test Pre Post +1 month % Change Patient 1 (5 yrs post) .59 m/s .81 m/s .95 m/s 61% Patient 2 (1.5 yrs post) .29 m/s .43 m/s .45 m/s 55% Patient 3 (10 yrs post) .83 m/s 1.03 m/s 1.14 m/s 37% 6 min walk test Pre Post +1 month % Change Patient 1 (5 yrs post) 170 m 207 m 250 m 47% Patient 2 (1.5 yrs post) 93 m 140 m 123 m 32% Patient 3 (10 yrs post) 271 m 300 m 285 m 5.2% Significant gains in therapy were maintained after the therapy was stopped – evidence of not just motor performance but motor learning, i.e. carryover.

Clinical Results International Conference on NeuroRehab Acute carryover in balance scores, stability in stance “The BL allows the user to involve their weaker leg more than would otherwise be possible...” Transfers Largest Studies to Date Gait Significant improvement in muscle engagement by EMG Symmetry of motion altered towards healthy “Changes post-stroke are consistently present and alter EMG towards normal…” Looked at more acute CVA patients in a more controlled gait lab that could measure gait symmetry, stability and muscle engagement via EMG.

Shepherd Center – TBI Case Study 23 y/o female s/p MVA Multiple skull fractures, L temporal SDH, IPH pons, midbrain, R cerebellar peduncle Patellar fracture, left transverse process fracture T1 Patient presented with: severe left hemiplegia poor spatial awareness mild left neglect poor visual acuity mild pushing tendencies

Mod/Max 2-3 (ARJO UE Support) 2 Min A (sit pivot) Mod A Initiated use of Bionic Leg 6 weeks post-admission (1 day after emergence from coma) 2-3 times per week for functional gait skills. Transfers Sit/Stand Gait 1 Max A (sit pivot) Dependent Mod/Max 2-3 (ARJO UE Support) 2 Min A (sit pivot) Mod A Dependent (ARJO < 50ft) Min A x 2 3 Min A (stand pivot) Min A Min A x 2 > 100 ft 4 Min A 1-2 200-300ft (no BL)

Activities 1 Pre-gait stance control, weight shifts, very limited gait (step-to pattern) Pusher Syndrome behaviors noted 2 Stance control, kicking ball with unimpaired LE while maintaining stance on left (20-30 reps), anterior weight shifts in sit/stands for increased symmetrical weight bearing during transitional movements, gait (step-through) 3 Continued ball kicks for weight acceptance left LE, lateral weight shifts to left, gait in open environments, stair training 4 Gait training without device, *no pushing behaviors noted

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