Khao Trong / เข่าตรง
The straight knee, known as Khao Trong in Thai, is the foundational knee strike in Muay Thai and serves as the entry point for all knee technique development. This powerful linear strike drives the knee directly upward along the centerline of the body, targeting the solar plexus, abdomen, and chest of the opponent. The straight knee is one of the most frequently used weapons in the clinch and is a staple of Thai stadium fighting, where fighters in the later rounds often rely heavily on knee exchanges to score decisive points with the judges.
To execute the straight knee properly, the fighter begins from a balanced Muay Thai stance with weight distributed evenly across both feet. The rear foot pushes off the ground as the hip drives forward and upward, propelling the knee along a vertical trajectory toward the target. The striking surface is the top of the kneecap and the area just above it on the lower quadriceps. The standing leg remains slightly bent to maintain balance and structural integrity, while the hips thrust forward to add mass and momentum to the strike. The arms play a critical role in the technique: the fighter should pull the opponent toward the knee using a collar tie, double collar tie, or body clinch, effectively doubling the impact force by combining the forward pull with the upward drive of the knee. The torso leans slightly back at the moment of impact to create additional clearance and power.
In traditional Thai fighting, the straight knee is considered one of the most honorable and effective weapons. Thai judges score knee strikes very favorably, especially when they visibly affect the opponent. Fighters like Dieselnoi Chor Thanasukarn, known as the Sky Piercing Knee, built entire careers around the devastating effectiveness of the straight knee from the clinch. The technique is deeply embedded in Muay Thai culture, with training camps across Thailand drilling straight knees into heavy bags, pads, and banana trees from a fighter's earliest days of training.
The straight knee can be set up in numerous ways. From range, a fighter can use a jab or push kick to close distance before entering the clinch and driving the knee home. In the clinch itself, the straight knee is thrown whenever the fighter achieves inside position or a dominant collar tie. It can also be used defensively as a counter when an opponent rushes forward recklessly, meeting their momentum with a well-timed knee to the midsection. Defense against the straight knee involves creating distance with frames and push-offs, turning the hips to deflect the strike, or scooping the incoming leg to off-balance the attacker. The straight knee is the essential building block upon which all other knee techniques are constructed, and mastering it is non-negotiable for any serious Muay Thai practitioner.