THE INTIAL INVESTIGATION OF THE CHURCH PEW EXERCISE (CPE) TO FACILITATE QUADRICEPS FUNCTION FOLLOWING TOTAL KNEE ARTHROPLASTY
500,000 total knee replacements are performed in the USA annually.1 Knee replacements are expected to rise to 3 million by 2030.2 When surveyed total knee replacement patients rate their satisfaction as very high when the studied question is inquiring about pain differences pre and post surgery. In contrast to the self reported outcomes, functional performance measures, such as the timed stair-climbing or walking test, depict only modest improvements following TKA. 3Total knee arthroplasty reduces pain and improves health-related quality of life in 90% of patients.4 However when these same patients are asked about function they rate their satisfaction very low one year post knee replacement. 5, 6 The goals of total knee arthroplasty are to decrease pain, improve functional mobility, such as walking, stair climbing and to promote return to physical activity. It is well established that TKA reduces pain post surgery however 30% of patients report dissatisfaction in their physical abilities 1 year following the surgery. 5 Statistically one year after post-op TKA patients walk 18% slower and climb stairs 51% slower and have quadriceps deficits of nearly 40% than their age matched non total knee counterparts. 6,7 Approximately 75% of TKA patients report difficulty negotiating stairs. 6 Another staggering statistic is that 24% of total knee patients fall in the first year. 8 In 2000 Lingard reported that only 26% of TKA patients are referred to outpatient rehabilitation following total knee arthroplasty.9 Based on the above mentioned information it is imperative that today’s rehabilitation programs for TKA needs to be critically examined and a new thinking process be implemented . Failure to do so can definitely impede the ability of the TKA patient’s long term functional abilities.
Individuals with knee osteoarthritis prior to undergoing a traditional Total Knee Arthroplasty on average have a 20% quadriceps deficit.10 It has been reported that at one year that deficit is 40% despite standard rehabilitation programs.7,11 Investigators have linked the decline in walking speed, stair climbing ability and falls to the persistent quadriceps deficit.7 Researchers who have incorporated neuromuscular electrical stimulation into the post –operative rehabilitation to augment traditional strengthening exercises found that patients who had the NMES walked and performed stairs faster and had less torque deficits than those patients who did not incorporate NMES into the rehabilitation program.12,13,14
So, what is it about the NMES? To answer this we must first review some basic electrical stimulation modality principles as well as the effects post operative effusions can have on quadriceps inhibition. NMES selectively recruits fast twitch type II muscle fibers before slow twitch type I fibers. Type II fibers are the first to atrophy following disuse immobilization. So can we speculate that the selective fiber recruitment of the NMES provides the necessary neural drive to the quadriceps muscle thus reducing the inhibitory effects of disuse immobilization following TKA surgery? Can we also clinically reason that post operative NMES delivered to the quadriceps has a muscle pumping effect thus reducing effusion?
Joint Replacement Quadricep Facilitation Exercise-"The Church Pew": it has been documented in the literature that prior to a knee replacement surgery the patient can have at least a 20% quadricep deficit. This deficit persists following a total knee replacement. Traditional knee replacement exercises do not specifically address the neural inhibition that occurs in the quadricep muscle. The persistent inhibition of the quadricep muscle affects a total knee replacement patient’s walking and stair climbing abilities. The "church pew" exercise facilitates the quadricep by causing an involuntary muscle contraction, just the way the quadricep muscle functions during the gait cycle. Traditional quadricep exercises are volitional contractions and thus do not stimulate the muscle functionally. The "church pew" exercise is a great way to get that neurological-re-education and augment the traditional exercises. The church pew exercise is for neuromuscular re-education of the quadricep and augments all the other traditional quadricep exercises. I recommend that you assess your patients gait before and after the exercise and document the change in stance time, speed and the patients subjective comments post exercise.
CHURCH PEW EXERCISE
Following my investigation of the quadriceps deficit that occurs following total knee arthroplasty and the review of the literature of implementing NMES I decided to explore where exactly does the TKA patients gait deviate. I studied many hours of TKA patients gait and concluded that those patients that had a gait deviation in stance phase resulted in a two to five inch excursion at initial contact to mid stance. Patients either had a genu recurvatum or a flexion moment type gait upon initial contact to weight acceptance .Another interesting finding was that the patients I studied all had a different ankle strategy than non TKA patients. The TKA patients consistently had a more rigid ankle from initial contact through stance phase. The patients I looked at were on average 6-9 weeks post and was either ambulating with a cane or no assistive device. The ankle was stiff and they would strike, deviate into recurvatum or slight flexion buckle. All of the patients that I studied had full extension passively and at least good quadriceps strength with manual muscle testing. My objective was to create an exercise that promoted an involuntary quadriceps contraction at the specific functional position that total knee patients gait deviates. So over a course of two months I experimented with various methods of implementing the CHURCH PEW EXERCISE. I had patients perform the exercise for 3o seconds, 60 seconds, and 90 seconds and there was no change in their gait speed or stair climbing speed. However when they tried it for two minutes there was a change so I tried three minutes and found it to be no more effective than two so I settled on two minutes. I then proceeded to study the church pew and compare it to patients who did not perform the exercise. Listed below are my initial investigation findings. The most striking finding was that during the sway (lowering) phase of the exercise both the quadriceps and hamstrings are working virtually in a co-contraction manner.
I then randomly assigned patients to two groups post TKA. Both groups had patients who were at least 3 weeks post TKA and not more than 7 weeks. The patients were from various orthopedic surgeons in Greensboro, North Carolina. They all underwent the traditional surgical approach. All patients went through the same rehabilitation regimen and kinetic activities however the 22 patients in the investigational group performed the CHURCH PEW EXERCISE for 2 minutes 4 times per day for 3 weeks. My investigation wanted to look at whether patients who performed the CHURCH PEW EXERCISE would have faster walking and stair climbing times. My outcome measurements were the Ten Meter Walk Test –TMWT and the 12 Step Stair Test.
INITIAL INVESTIGATION –EMG FINDINGS OF THE CHURCH PEW EXERCISE-CPE
When observing this very initial evidence it appears that the church pew exercise might be more relevant to improve activation of the quadriceps during weight acceptance.
So the question we should be asking ourselves was how could a simple exercise like the CHURCH PEW EXERCISE acutely improve TKA patients walking speed and stair climbing abilities? I would like to discuss a couple of thoughts I have. First of all the CHURCH PEW EXERCISE facilitates an involuntary quadriceps contraction at the specific angle of motion that the lower extremity goes through during gait. This result in a neural drive to the kinetic chain that does not exist with any of the standard therapeutic and kinetic activities performed during TKA rehab. I believe that triggering this neuromuscular drive enhances the effectiveness of the traditional hypertrophy exercises clinicians use to strengthen patients and improve gait following total knee arthroplasty. I also strongly feel that the CHURCH PEW EXERCISE facilitates ankle mobility that is often lacking following TKA. As stated previously TKA patients tend to hold their ankle in a rigid position at initial contact through push off. This results in the inability of the kinetic chain to properly go through the necessary supination at initial contact, pronation at mid stance and re-supination at push off. If the ankle joint is held rigid, the sequence of the gait cycle is obviously compromised. The CHURCH PEW EXERCISE allows the natural femoral and tibia rotational movements during gait creating the necessary stride length , cadence and proprioception.
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