Effects of Motor Imagery Intervention on Functional Recovery Following Total Knee Arthroplasty
Effects of Motor Imagery Intervention on Functional Recovery Following Total Knee Arthroplasty
The knee osteoarthritis becoming a leading cause of disability among older adults'
 population. When conventional treatments fail, a total knee arthroplasty (TKA) is suggested.
 Although TKA treatment significantly reduces pain and improve mobility of patients, there is
 still high prevalence of patients whose neuromuscular function is impaired up to three years
 following TKA, which can be directly prescribed to poor or/and inadequate rehabilitation
 practice. Thus, motor imagery (MI) is proposed as additional rehabilitation tool to
 convention physical therapy to reduce decline of neuromuscular function in early days
 post-surgery. Recent studies showed that MI could facilitate learning and acquisition of
 motor skills, as well as maintain and retain previously acquired motor skills, which may be
 beneficial for those who undergo TKA. It represents an incentive in the process of motor
 learning and the transfer of the mental scheme of the motion pattern into the process of
 movement execution. Measuring neuromuscular function pre- and post-TKA could be unique
 opportunity to provide empirical evidence about its additional therapeutic effects. Outcomes
 of proposed research project could serve to improve existing intervention programs applied in
 rehabilitation protocols following TKA surgery as well as other orthopedic interventions.
 This would also contribute to the successful return of individuals after an injury to their
 everyday working routine. We hypothesized that MI practice group will experience better both
 subjective and objective measures of functional performance compared to control group that
 will be subjected to routine physical therapy only.
TKA is widely considered to have a successful outcomes, comparing pre and postoperative
 scores on pain and both subjective and objective functional measures. Nevertheless, a
 significant proportion of patients report continuing pain, functional limitations, and
 dissatisfaction up to three years after the surgery. Thus we planed to conduct intervention
 study.

 OBJECTIVES:

 • Primary goal of the research is to determine how the MI practice intervention will
 influences on the recovery of neuromuscular and locomotor function following TKA.

 Specific goals of the research are as follows:

 -  To examine effects of MI practice intervention to other measured parameters as follows:

 1. maximal isometric strength of knee extensors,

 2. maximal voluntary activation level

 3. spatio-temporal gait parameters during different gait velocities under single- and
 dual-task conditions,

 4. contractile muscle parameters,

 5. electromechanical efficiency index,

 6. self-reported measure of knee function (OKS and LEFS),

 7. and pain level assessed by Visual Analogue Scale (VAS).

 HYPOTHESIS:

 The main hypothesis of this dissertation is that the group, which will perform
 motor imagery practice intervention will have fewer decline in motor functions
 following TKA surgery.

 H1: Motor imagery (MI) leads to lower functional decline at one-month period after
 surgery as compared to control group (CON).

 H1.1: Patients in MI intervention group have fewer decline in maximal isometric
 knee extensors strength.

 H1.2: Patients in MIp intervention group have fewer decline in spatio-temporal gait
 parameters during different gait velocities under single- and dual-task conditions.

 H1.3: Patients in MI intervention group have fewer decline in voluntary muscle
 activation level.

 H1.4: Patients in MI intervention group will not experience significantly greater
 decline in contractile muscle parameters as compared to CON group.

 H1.5: Patients in MI intervention group have fewer decline in electromechanical
 efficiency index.

 H1.6: Patients in MI intervention group have better self-reported knee function
 assessed by self-reported questionnaires.

 H1.7: Patients in MI intervention group have fewer pain level assessed by VAS.

 1. Methods

 Participants:

 N = 26 (man/woman) of which:

 1. Symptomatic population / n = 26; have already determined date for TKA surgery

 Participants will be recruited from Valdoltra orthopedic hospital (Ankaran,
 Slovenia).

 Inclusion criteria: scheduled for unilateral TKA secondary to osteoarthritis; age
 from 50 to 80 years old; participants were not engaged in preoperative treatments;

 Exclusion criteria: participants who had a previous history of TKA on the same side
 as the surgery; body mass index of 40 kg/m2 or higher; bilateral TKA's; patients
 with a history of any neurological disorder including Cerebral Vascular Attack,
 Multiple Sclerosis, or Parkinson's disease; patients with Rheumatoid Arthritis or
 active cancer; thrombose; bleeding after surgery; previously participation in
 imagery training.

 Sample Size:

 Isometric knee extension strength of the surgical leg was defined as the primary
 outcome variable for the power analysis. The sample size was calculated based on
 Hopkins recommendations (W. G. Hopkins, 2006) using online available spreadsheet
 (http://sportsci.org/resource/stats/index.html). Raw mean difference in change
 (RDC) was calculated based on pilot study of my own (RDC = 48,51 Nm) (unpublished
 data). Further, minimal clinically important change (MCIC) (MCIC = 21,89 Nm) (van
 der Roer, Ostelo, Bekkering, van Tulder, & de Vet, 2006) was calculated based on
 standard error of measurement (SEM) (SEM = 7,9 Nm) from study of Lienhard (Lienhard
 et al., 2013) that assessed reliability of isometric knee extensor strength of TKA
 patients. Given that in clinical practice the drop out of subjects is common
 because of many reasons (aging process, comorbidities, post-surgery complications),
 we adjusted originally calculated sample size by following formula: N1 = n/(1-d)
 (Sakpal, 2010) where N1 is adjusted sample size, n is the sample size required as
 per proposed formula ( N = 7 per group) and d is the drop-out rate (d = 0,25). This
 resulted in a target sample size of 10 in each of two groups (Mip and control). The
 recruitment of the patients will continue until the target sample size is achieved.

 2. Procedure

 - Ethical permission (already approved) - Ethics Committee of Valdoltra orthopedic
 hospital.

 - Measurement assessment participants PRE-surgery (one day before surgery on
 average)

 - MI practice intervention

 - Measurement assessment participants POST-surgery 1 (one month after surgery on
 average)

 - Measurement assessment participants POST-surgery 2 (one year after surgery on
 average)

 The patients will be randomized into two groups: the experimental MI practice group
 (MIp) and control group (CON), which will have common in patient and home-based
 physical therapy only. Subjects in both groups will receive one daily continuous
 passive motion (CPM) session (Kinetec Performa), beginning on the second day after
 TKA (immediately after intensive care) until discharge (5 to 7 days). Nurses will
 install the CPM device, by the standardized procedure. Identical installations will
 be performed for both groups: subjects laying supine in their bed, and the CPM
 device will be placed under the operated leg with the knee extended. For stability,
 one strap will surround the subject's thigh, another strap surrounds the subject's
 lower leg, and the apparatus will be prevented from sliding down by the edge of the
 bed. The CPM will be used for 45 minutes continuously, including a 5-minute warm-up
 period.

 Patients included in MI group will have intervention based on motor imagery
 technique with beginning immediately after intensive care. In detailed, they will
 be advised to imagine maximal voluntary isometric contractions (MViC). MViC imagery
 practice will be progressive. Thus, it will be performed in two sets of 25
 repetitions with 2 minutes of inter-sets rest period, with 10 additional trials in
 week three and four. Each MViC repetition should be sustained for 5 seconds,
 followed by 5 seconds of inter-repetition rest periods. Additionally, after every
 five contractions, participants will have a 20 seconds of rest in order to minimize
 the onset of mental fatigue (Rozand, Lebon, Stapley, Papaxanthis, & Lepers, 2016).
 Following 5 days of MIp the participants were advised to take a break from MIp for
 two days in a raw.

 After release from the hospital participants from MIp group will be supplied with
 audio description of exercise they need to perform in order to better concentrate
 to MIp task, rather than programme variables itself. Additionally, after release
 from hospital both groups will be supplied with a physical exercise program that
 they need to perform in home-based environment (like that one they will have in the
 hospital). In general, exercise programme considered active and passive knee
 flexion, abduction and adduction of the hip in the horizontal plane. Knee extensor
 muscle strengthening exercises such as unilateral knee extension with resistance of
 healthy leg, bilateral sit up from the higher chair/the high was adjusted by the
 pillow, unilateral weight bearing eccentric contraction supported with crutches
 etc. Next, functional exercises with weight bearing were adviced with attention of
 transferring the preasure (personal weight) on operated leg as much as possible.

 Each participant will be called by the phone every day in order to monitor their
 adherence to the prescribed exercise programme (lower than 80% of adherence will be
 excluded from the post analysis).

 Given that reported placebo effect in psychological outcomes of exercise training
 is small (ES = 0,20) (Lindheimer, O'Connor, & Dishman, 2015), to control it and
 additional socio-psychological influence of MIp instructor on the MIp outcomes, we
 will ensure the same conditions for the other group and spend the same amount of
 time with them (approximately 15 minutes per day) with each patient (verbal
 communication on site/in hospital or by telephone call/after discharge) regardless
 of his randomization to the group.

 Measurement assessments:

 Measurement assessment will be conducted in period before TKA (BT), and 1 month
 after the surgery.We will evaluate:

 I. Cognitive assessment:

 - Montreal Cognitive Assessment (MoCA): cognitive screening tool for Mild Cognitive
 Impairment

 II. Anthropometry:

 - Body weight and height (Stable stadiometer Seca, Birmingham, UK) and body
 composition (Bio-impedance system MALTRON BF-906).

 III. Functional status:

 - flexibility of knee joint (flexion and extension ROM) - assessed by manual
 goniometer

 - agility and dynamic balance (Timed "Up & Go" Test)

 - Sit to stand (30 seconds)

 - spatio-temporal gait parameters (STGP) during different gait velocities will be
 measured by OPTOGAIT system (Microgate, Bolzano, Italy) under single- and dual-task
 conditions.

 -  Hand grip strength along with both the knee extensors and flexors muscles
 maximal voluntary isometric strength (MViC) (isometric dynamometer S2P)

 -  Self - reported functional assessment (OKS and LEFS questionnaires)

 IV. Muscle function:

 -  contractile muscle parameters (Tensiomyography)

 -  electromechanical efficiency index (Tensiomyography and M-wave module)

 -  Voluntary activation level (using double interpolated twitch technique) V.
 Pain level - Visual analogue scale (VAS)
Inclusion Criteria:

 -  patients scheduled for unilateral TKA secondary to osteoarthritis;

 -  age from 50 to 80 years old;

 -  participants were not engaged in preoperative treatments

 Exclusion Criteria:

 -  participants who were undergoing a revision TKA;

 -  body mass index (BMI) greater than 40 kg/m2;

 -  participants who were receiving a bilateral TKA's;

 -  uncontrolled hypertension;

 -  diabetes mellitus;

 -  a history of any neurological disorder;

 -  multiple sclerosis;

 -  Parkinson's disease;

 -  patients with rheumatoid arthritis or active cancer;

 -  previous history of deep vein thrombosis;

 -  contralateral knee OA (as defined by pain greater than 4/10 with activity)