## 2 Case Report
The exercise volumes and external loads for other resistance exercises ranged between body mass and 25 kg (Table 1). Initially, the patient performed an aerobic exercise on a stationary bike, which was also aimed at improving knee flexion angle. Once a knee flexion angle was recovered by 90% of the preoperative level, the patient performed a treadmill jog. Due to the association of hip joint flexibility and knee pain [15], static stretch (especially on hip joint flexion and extension) was performed as a cool-down strategy. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Treatments** & \multicolumn{2}{c}{**Parameters**} \\ \hline NSAIDs & \(\bullet\) & Celecoxib 200 mg per day \\ • & \(\bullet\) & Naproxen/Esomeprazole 500/20 mg twice a day \\ \hline Cryotherapy & \(\bullet\) & Focal knee joint cooling: an ice bag (filled with 1 L of cubed ice) on top of the patella for 30 min \\ • & \(\bullet\) & Cold-water immersion (17–19 \({}^{\circ}\)C): up to the iliac crest for 20 min \\ \end{tabular}
\end{table} 
Table 1: Summary of postoperative interventions. Figure 1: Magnetic resonance images for diagnosis (left: (**A**); right: (**C**)) and arthroscopy images (**B**,**D–F**). Note that (**E**,**F**) are images obtained after surgery. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Treatments** & & **Parameters** \\ \hline \multirow{4}{*}{Electrotherapy} & \(\bullet\) & NMSE: 2500 carrier frequency, burst at 50 Hz, on/off time: 10/20 s, maximum tolerable intensity for 30 min \\  & \(\bullet\) & TENS: 150 \(\upmu\)s with 150 Hz for 30 min at sensory level (no visible muscle contraction) for 30 min \\ \hline \multirow{4}{*}{Resistance Exercise (intensity)} & \(\bullet\) & Straight leg raises: 10 reps \(\times\)3 sets on each leg (5–20 kg) \\  & \(\bullet\) & Standing hip abductions: 15 reps \(\times\)2 sets on each leg (5–10 kg) \\  & \(\bullet\) & Knee extensions: 7–8 reps \(\times\)3 sets on each leg (DAPRE \\  & & technique) \\  & \(\bullet\) & Leg presses: 7–8 reps \(\times\)3 sets (DAPRE technique) \\  & \(\bullet\) & Half squats: 15 reps \(\times\)2–3 sets (5–25 kg) \\  & \(\bullet\) & Dead lifts: 7–8 reps \(\times\)3 sets (5–25 kg) \\  & \(\bullet\) & Lunges: 15 reps \(\times\)2–3 sets (body mass) \\ \hline \multirow{4}{*}{Aerobic exercise} & \(\bullet\) & Stationary bike: within pain-free knee flexion angle for 20 min \\  & \(\bullet\) & Treadmill walk/jog: 2\% inclination at 5.5 to 8.7 km/h for 30 min \\ \hline \multirow{4}{*}{Stretching Exercise} & \(\bullet\) & Passive stretching using a stretching strap: hamstring, iliopsoas, and hip adductors (a 30-s hold \(\times\)3 sets) \\ \cline{1-1}  & & \\ \cline{1-1}  & & \\ \cline{1-1}  & & \\ \  
During the rehabilitation period, the NPRS during daily activities and the circumference (same measurement as the initial evaluation) and skin temperature of the right knee joint (on the lateral boarder of the patella) were measured daily. A thermistor probe connected to a digital thermometer logger (N543, NT logger, NKTC, Tokyo, Japan: 60 Hz) and covered with film dressing was used to record skin temperature [16]. Functional outcomes using the Kujala AKP scale [17], International Knee Documentation Committee score [18], and lower-extremity functional scale [19] were obtained biweekly, and a percentage of each outcome score was averaged. Knee flexion ROM (the same measurement as the initial evaluation) and external loads for knee extension and leg press exercises were also recorded every two weeks.