In a written statement, the pilot reported that as the airplane was about 3 miles from the destination airport, he configured for landing by adding full flaps. He opted to perform a soft-field landing for the purpose of practice and began managing the descent with the throttle control. As the airplane transitioned to short final, it was configured in a nose-high stabilized approach. With the airplane 150 feet from the runway threshold, the pilot added right rudder in attempt to gain visibility out the window straight ahead. As the airplane was 20 to 30 feet above ground level (agl) and 100 feet from the threshold, the pilot applied power to arrest the descent. The increase in power, in combination with the rudder input, resulted in the airplane's left wing contacting the ground. In the section titled "RECOMMENDATION" in the NTSB Pilot/Operator Report, form 6120.1/2, the pilot stated that the application of rudder while adding full power created enough instability to drop the wing. The pilot further added that there were no preimpact mechanical malfunctions or failures with the airframe or engine.