A portable motion analysis system for detecting a deviation of a user movement from a motion profile for an improved exercising of a sport, the system comprising: a first sensor module with at least one first acceleration sensor or another motion sensor, a first data transmission unit and a first processing unit, wherein the first sensor module can couple to a body part of the user and is adapted to detect first acceleration values of the body part as first sensor data; and a second sensor module with at least one second acceleration sensor or another motion sensor, a second data transmission unit and a second processing unit, wherein the second sensor module can couple to a further part of the user and is configured to detect second acceleration values of the further body part as second sensor data, characterized in that the first sensor module and the second sensor module are installable or attachable to or in a sport equipment and each can couple to a motion of a corresponding leg of the user, wherein the first processing unit is adapted to compare the detected acceleration values from the first acceleration sensor with the motion profile, and the first data transmission unit is configured to transmit to the second sensor module at least those data related to the first acceleration values that deviate from the motion profile, and wherein the second processing unit is configured to compare the second acceleration values of the second acceleration sensor with the motion profile and with data transmitted from the first sensor module to thereby put the sensor data in a spatial and temporal relation and to enable an overall assessment, and to confirm a movement deviation of the user from the motion profile and to output it over the second data transfer unit. a first sensor module with at least one first acceleration sensor or another motion sensor, a first data transmission unit and a first processing unit, wherein the first sensor module can couple to a body part of the user and is adapted to detect first acceleration values of the body part as first sensor data; and a second sensor module with at least one second acceleration sensor or another motion sensor, a second data transmission unit and a second processing unit, wherein the second sensor module can couple to a further part of the user and is configured to detect second acceleration values of the further body part as second sensor data, characterized in that the first sensor module and the second sensor module are installable or attachable to or in a sport equipment and each can couple to a motion of a corresponding leg of the user, wherein the first processing unit is adapted to compare the detected acceleration values from the first acceleration sensor with the motion profile, and the first data transmission unit is configured to transmit to the second sensor module at least those data related to the first acceleration values that deviate from the motion profile, and wherein the second processing unit is configured to compare the second acceleration values of the second acceleration sensor with the motion profile and with data transmitted from the first sensor module to thereby put the sensor data in a spatial and temporal relation and to enable an overall assessment, and to confirm a movement deviation of the user from the motion profile and to output it over the second data transfer unit.