Learning, practicing, and repetition are key to skill development as well as the development of strength. Executing a repetition better than you did before is important in progressive overload. If you are using manual resistance in your program, make sure each athlete learns the rules, practices the rules and performs each repetition optimally.
Manual Resistance Rules
1). Each athlete must know and understand the rules.
2). The Lifter begins each exercise with the goal of 6-8 reps. This requires pacing. In other words, the first repetition is not an all out effort. The effort must be increasing for every subsequent repetition.
2a). The Spotter should allow the lifter to perform each repetition at the same pace or speed of movement. This will require different amounts of pressure by the spotter during the rep (because of leverage). The lifter will feel as though the resistance is similar at all joint angles (the resistance will feel smooth).
3). The lowering phase of every repetition should be slower than the raising phase. A guide in learning manual resistance is raise the involved limbs up in 1-2 seconds or at a 1-2 count and lower them in 4-5 seconds or at a 4 or 5 count.
3a). The Spotter must make sure that they feel more force by the lifter during the lowering phase of each repetition.
4). The Lifter should continually contract their target musculature during the raising phase and the lowering phase of every repetition.
4a). The Spotter must give feedback to the lifter to ensure there is always a constant contraction on every repetition performed. The spotter should identify any relaxation or loss of force by the lifter during the movement.
5). The Lifter should pause with pressure against the spotter's resistance at the top of every movement. Pausing with pressure and no relaxation is extremely difficult.
5a). The Spotter should insure the lifter is applying force at the top of the movement. The spotter must feel if the lifter is relaxing. The spotter must ease slowly into the lowering phase of the exercise. Slowly easing into the lowering phase or decent is extremely important.
6). The exercise is completed when the athlete reaches momentary muscular failure.