The study investigated whether high-intensity (HI) strength training increased pain after total knee replacement (TKR) compared to low-intensity (LI) training. It found that the HI group experienced no more pain or stiffness than the LI group. Both groups improved significantly from baseline on all outcomes measured. The HI exercises were well tolerated, with no patients withdrawing. The study concluded that progressive, submaximal exercise after TKR is safe and tolerated by patients, and more intense interventions should be considered to potentially provide better long-term benefits.

1. DOES HIGH INTENSITY TRAINING INCREASE PAIN
AFTER TOTAL KNEE REPLACEMENT?
A PROSPECTIVE COHORT STUDY
Results
The HI group experienced no more pain or stiffness
than the LI group (p>0.05) (Figure 1). The high-
intensity exercises were well tolerated, and no
patient withdrew from treatment. Both groups
improved significantly from baseline for all outcomes
(p<0.05). No significant differences between groups
were found for all investigated functional outcomes
after treatment (p>0.05).
Conclusions
Introducing progressive submaximal exercise after
TKA is safe and well tolerated by patients. The
implementation of more intense interventions should
be considered. Further studies with longer follow-up
are needed to investigate the long term effects on
symptoms and functional outcomes in patients after
TKA.
Discussion
The addition of high-intensity exercises initiated
early in the course of recovery after TKA did not
increased pain or stiffness, and the knee
performance of the two groups was comparable at a
short-term follow-up post rehabilitation. At discharge,
all the subjects in both groups compared to baseline
assessment performed about 10 seconds faster on
the walking test, and showed a mean decrease in
pain of about 2 VAS-points.
02468
H L
vasd_t0 vasd_t1
Graphs by gruppo
References
1. Pozzi F, Snyder-Mackler L, Zeni J. Physical exercise after knee arthroplasty: a systematic review of controlled trials. Eur J Phys Rehabil Med.
2013;49(6):877-92.
2. Silva M, Shepherd EF, Jackson WO, Pratt JA, McClung CD, Schmalzried TP. Knee strength after total knee arthroplasty. J Arthroplasty. 2003;18:605-611.
3. Bade MJ, Stevens-Lapsley JE. Early high-intensity rehabilitation following total knee arthroplasty improves outcomes. J Orthop Sports Phys Ther
2011;41:932-41.
1Student at School of Physiotherapy, University of Eastern Piedmont, Fossano (CN), Italy
2Unit of Rehabilitation and Functional Recovery, Casa di Cura La Residenza, Rodello (CN), Italy
3Student at School of Physiotherapy, University of Eastern Piedmont, Novara, Italy
4Laboratory of Ergonomics and Musculoskeletal Disorders Assessment, Division of Physical Medicine and
Rehabilitation, Istituti Clinici Scientifici Maugeri IRCCS, Veruno, (NO), Italy.
Low Intensity group
(n=21)
High Intensity group
(n=18)
Frequency: 3/week
Intensity: 60-
80%1RM
Type: leg extension -
squat
Time: 15’/session
Volume: 10-15 rep
(week 1), 8-12 rep
(week 2)
Morra Valentina1 PTs, Piano Leonardo2 OMPT, Marivo Simone3 PTs,
Sartorio Francesco4 MSc, Vercelli Stefano4 PhD
Material and Methods
This study had an observational, randomized,
controlled, pragmatic design. One week after surgery,
39 inpatients were randomized to a HI (n=18) or LI
(n=21) group. Both groups performed two-to-three
weeks of rehabilitation aimed to improve strength (with
low-intensity exercises), range of motion (ROM), and
gait. In addition, the HI group performed two high-
intensity strength exercises (leg extension and squat)
3 times/week (Box 1). The primary outcomes were
symptoms, i.e. pain during gait (VAS) and stiffness
(WOMAC stiffness subscale), while secondary
outcomes were function (10meter walking test, 5 times
sit-to-stand, WOMAC function subscale). The two
groups were compared by two-way ANOVA. Any
further complaint (swelling, decreased walking
endurance or knee ROM) was also recorded for safety
assessment of the high-intensity regimen.
Background and Objectives
Rehabilitation programs after total knee arthroplasty (TKA) usually include exercises to improve muscle
strength.1,2 Fear of symptoms exacerbation - such as pain, stiffness, or swelling - often induces clinicians to use
exercises at low-intensity, despite growing evidence that high-intensity exercises may produce better
outcomes.3
This study aimed to investigate the effects on symptoms of high-intensity (HI) strength training as an adjunct to
a comprehensive rehabilitation program based on low-intensity (LI) exercises.
Figure 1. Comparison of pain and stiffness between groups over time (Tukey box
plots). On the left is shown pain, expressed as visual analogue scale score; on
the right is shown stiffness, expressed as WOMAC stiffness subscale score.
02468
H L
wstiff_t0 wstiff_t1
Graphs by gruppo
Box 1. both group underwent the same rehabilitation program except for the
intensity of strength training parameters. HI exercises were set according to
American College of Sports Medicine (ACSM) following the FITT-V principles.
Frequency: 3/week
Intensity: <60% 1RM
Type: leg extension -
squat
Time: 15’/session
Volume: 10-15 rep
(week 1), 8-12 rep
(week 2)
subjects recruited
(n=39)
Pain (VAS)
8
4
2
6
t0 t1 t0 t1t1t0 t0t1
HILI LI
Stiffness
HI