Pain and the resulting gait are the main problems of patients with knee osteoarthritis. Here, we propose The Lower Body Positive Pressure Treadmill Intervention Protocol, which includes both clinical assessment and treatment models for the rehabilitation of lower extremity motor functions in knee osteoarthritis. The LBPP treadmill protocol allows people to achieve exercises with relatively low heart rate, blood pressure and oxygen consumption, so it is safer and more effective than full-weight exercises for knee OA patients with cardiopulmonary disease.
Visual demonstration of this method is critical for safe operation of the LBPP training system and understanding of our protocol. Demonstrating the procedure will be Dr.Junjie Liang, Dr.Qiang Lin, PT Hongxin Chen, and Dr.Shijuan Lang from my lab. Begin the clinical assessment by asking the patient to describe their pain intensity from zero to 10 where zero is no pain and 10 is the worst pain.
Then conduct the active/passive knee joint range of motion assessment using a handheld two arm goniometer. Then conduct the Western Ontario and McMaster Universities Osteoarthritis Index or WOMAC by asking the patient to mark the corresponding position of pain or limited function on a straight line for five pain-related items, two stiffness items, and 17 functional items. Zero indicates no pain or no function limitation.
10 indicates severe pain or extreme limited function. Following the WOMAC, conduct two optional assessments:the Knee Injury and Osteoarthritis Outcome Score or KOOS, and/or the European Five Dimensional Health Scale, EQ-5D, to assess pain symptoms and quality of life. Then for the 10-meter walk test ask the patient to perform three consecutive 10-meter walk test trials at a self-selected pace for safety and comfort.
Ask the patient to walk without assistance for 10 meters and measure the time taken for the middle six meters. Next, to conduct The Timed Up and Go test ask the patient to perform three consecutive trials at a self-selected pace. Stand up, walk three meters, turn, walk back and sit down.
Lastly, perform a 3D gait analysis. To do this, position 22 spherical markers on the patient's anatomical landmarks based on the Davis Protocol. Then position six surface EMG electrodes on the bilateral rectus femoris, semitendinosus and long head biceps femoris of the patient.
Ask the patient to hold an orthostatic position for at least three to five seconds with the feet aligned in order to avoid having one foot in the more anterior or posterior position with respect to the other. Instruct the patient to walk with a self-selected speed along the fiver-meter walkway five times. Finally, remove all the spherical markers and EMG electrodes from the patient and save all the collected data for later processing.
Begin by introducing the lower body positive pressure or LBPP treadmill training process and related precautions to the patient. Next, check the patient's blood pressure and heart rate. Determine the size of the air seal shorts according to the waist circumference of the patient and ask the patient to put on the shorts.
Turn on the treadmill by operating the switch located on the front cover of the system and run the self-testing of the antigravity treadmill. Lower the cockpit. And have the patient step into the fabric enclosure of the antigravity treadmill.
Lift the cockpit to the appropriate height according to the LBPP training model such that the cockpit height is at the anterior superior iliac spine with a walking model, and slightly below the femur's great trochanter for the squatting model. Once the cockpit is in place, zip the patient into the antigravity treadmill. Use the safety lanyard supplied with the machine to secure the clip onto the patient's clothing, which is essential for emergency stopping during the training process.
Then instruct the patient to stand still on the surface of the treadmill belt to allow the system to hold and weigh the patient's a full body weight without any support from any part of the system, and then press the start button to perform an antigravity treadmill system calculation for accurate unweighting. Lastly, adjust the positions of three cameras supplied with the machine to obtain the synchronized video feedback during the training process to help the patient correct abnormal movement patterns. For the training session, start the warm-up with the following settings:five minutes with the speed zero to two miles per hour, BW 65%incline 0%Increase speed by 4 miles per hour and body weight support in 7%increments per minute.
Then perform the walking model session with the following settings:15 minutes with the speed at two miles per hour, BW at 65%and incline at 0%Perform the cool down session with the following settings:five minutes with the speed at two to zero miles per hour, BW 65 to 100%incline at 0%Decrease speed by 4 miles per hour, and body weight support in 7%decrements per minute. End up with the squatting model session with the following settings:five minutes with the speed at zero miles per hour, BW 50%incline 0%AROM zero to 50 degrees or the maximum tolerable joint range of motion within 50 degrees, 30 seconds of squatting followed by a 30-second rest period. Finally after two weeks of the LBPP training session, reevaluate the patient using the standardized tests and 3D gait analysis.
These results indicate that the 10-minute walk test decreased from 4.1 seconds at pre-training to 3.3 seconds at post-training. The TUG test decreased from 9.1 seconds at pre-training to 8.2 seconds at post-training. After two weeks of LBPP training, patients showed an improvement in total WOMAC scores, pain subscales, stiffness subscales, and function subscales.
The total VAS pain scores did not change after two weeks of treatment. The right swing phase increased. And left swing phase decreased from pre-training to post-training.
The right side length decreased, but the left side stride length increased from pre-training to post-training. Further, the mean velocity and cadence increased from pre-to post-training, but the step width decreased. Our LBPP training session consists of the walking and squatting modules.
The walking module focuses on improving walking function and the squatting module focuses on enhancement of the tight muscles'joints. If the patient can not tolerate the squatting training module, only perform the walking module.
